CN101651614A - Method and device for scheduling multiport queues - Google Patents

Abstract

The invention discloses a method and a device for scheduling multiport queues. The method comprises the following steps: when a new connection enters an empty queue in any one of ports, and if the first time value of a timer of the port is larger than or equal to a preset time delay value, setting a virtual start time scale of the empty queue to be a virtual time of a prior system; or when the present scheduling of the prior port is finished, and if the second time value of the timer of the prior port is larger than or equal to the preset time delay value, setting virtual end time scales of all empty queues in the prior port to be the virtual time of the prior system, and resetting the timer of the prior port. The embodiment of the invention provides one timer for each port and then executes the time scale update to the corresponding queue according to the size of the timer of the port, and in the application of multiport, the first time delay of the new queue enqueueing is controlledwithin the preset time delay value range.

Description

The scheduling multiport queues method and apparatus

Technical field

The embodiment of the invention relates to network communications technology field, relates in particular to a kind of scheduling multiport queues method, scheduling multiport queues device and data communications equipment.

Background technology

For at packet network, as asynchronous transfer mode (Asynchronous Transfer Mode, abbreviation ATM) provides service quality (Quality of Service in the packet switching network, abbreviation QoS) assurance, must be at grouped network equipment, as taking suitable scheduler in ATM switch, the atm router, utilize suitable array dispatching method to carry out the scheduling of formation, to guarantee the QoS performance of packet network.Usually, the QoS service parameter comprises packet delay, delay variation, Loss Rate and throughput etc., the qos parameter that different business needs is different, and for (the Constants Bit Tate of the fixed bit rate in the ATM packet switching network, be called for short CBR) professional, because the CBR business generally is used for supporting the real time business relatively more responsive to delay variation, as voice, video traffic etc., so it will be compared other business to the time delay in the qos parameter and time delay shake higher requirement is arranged.

Packet equity queuing (Packet Fair Queuing, abbreviation PFQ) dispatching algorithm is to use more and comparatively ripe a kind of packet scheduling algorithm at present, it can guarantee the reserved bandwidth that connects, maximum end-to-end time delay and delay variation, is the key technology that realizes QoS.The basic principle of PFQ dispatching algorithm is: for whole system is provided with a system virtualization function of time, offered the volume of services of all Business Streams in order to the recording dispatching device during current active; According to the reserved bandwidth and the system virtualization function of time that connect, to calculate one for each grouping that connects and write out falsely the beginning or finish markers, the markers of each formation is the markers of team's head grouping of formation for this reason; System is according to certain grouping selection strategy, according to the markers size of individual queue all formations sorted, and its team's head grouping is served one by one.

In the prior art, shaping dummy clock (Shaped Virtual Clock, abbreviation ShVC) dispatching algorithm is a kind of common PFQ dispatching algorithm, compare other PFQ dispatching algorithm, the empty function of time that defines in the ShVC dispatching algorithm and grouping selection strategy are respectively: adopt actual clock as the system virtualization function of time; Adopt preferential (the Smallest Eligiblevirtual Finished of minimum legal virtual end markers, abbreviation SEFF) principle is as the grouping selection strategy, when promptly the target grouping is served when preferentially selecting to have the virtual end of minimum, this grouping also need be satisfied the condition of " legal ", herein " legal " refers to, and the virtual beginning markers of this grouping should be less than or equal to the system virtualization clock.Because these characteristics of ShVC dispatching algorithm, it can well control professional time delay, shake, and also fairly simple in realization, therefore often is used in the CBR business in the atm network, especially is used in the single port application of ATM switch.

Because the grouping selection strategy that the ShVC dispatching algorithm is supported is the SEFF strategy, therefore current selected grouping of serving must be satisfied the condition that virtual beginning markers is less than or equal to current system virtualization clock, and because in the ShVC dispatching algorithm, what target size comparative approach adopted when virtual is annular method relatively, promptly in the count range of a virtual time function, the target difference is carried out size relatively to it when virtual by two, these two magnitude relationship of target when virtual are followed the change of both differences and are changed, therefore for any two virtual markers, if be designated as variate-value when one of them is virtual, then magnitude relationship between the two may change.

When the ShVC dispatching algorithm is applied in the ATM switch of multiport, for the current port that is not scheduled, when wherein certain empty queue has new connection to join the team, target was upgraded when system can't carry out virtual end to it, and can only one initial value be set for the virtual end markers of the last grouping of this formation, and this initial value is big or small indefinite, therefore when this port obtains the dispatcher meeting again, system is according to the indefinite initial value of this size, according to annular method relatively, the virtual beginning markers of this formation that calculates may not be less than or equal to the current system virtualization time, does not promptly satisfy the SEFF principle.And because port translation time uncertain between the port, may cause this new connection need wait for that the long period just can be scheduled, thereby cause in the ShVC dispatching algorithm, the time delay that the connection first of formation obtains dispatching is bigger, the bigger problem of promptly delaying time first.

Summary of the invention

The embodiment of the invention provides a kind of scheduling multiport queues method and apparatus, in order to solve in the prior art ShVC dispatching algorithm in the application scenarios of multiport, because be uncertain value the change-over time between the port, and the end markers of the head grouping of individual queue in the current port that is not scheduled can't obtain upgrading in time of system, thereby during the port translation that causes, the time delay that the connection of newly joining the team of empty queue may occur is big, need long defective of stand-by period, with guarantee multiport use in the requirement that time delay and time delay are changed of the CBR business of atm network.

The embodiment of the invention provides a kind of scheduling multiport queues method, comprising:

When having new connection to enter an empty queue in the arbitrary port in a plurality of ports, if the very first time of the timer record of described arbitrary port is worth more than or equal to default time delay value, the virtual beginning markers of described empty queue is set to the current system virtualization time;

Perhaps, when this when scheduling of finishing when front port, if second time value of described timer record when front port is more than or equal to described default time delay value, the virtual end markers of described all empty queues in front port is set to the current system virtualization time, and with described timer zero clearing when front port;

Described when front port be a port in described a plurality of port, described very first time value is dispatched to described new connection and enters the blanking time of described empty queue from finishing the last time for described arbitrary port, and described second time value is describedly to be dispatched to described blanking time of finishing described this scheduling when front port from finishing the last time when front port.

The embodiment of the invention provides a kind of scheduling multiport queues device, comprising:

The first virtual markers updating block, be used for when having new connection to enter an empty queue in arbitrary port of a plurality of ports, if the very first time of the timer record of described arbitrary port value is more than or equal to default time delay value, the virtual beginning markers of described empty queue is set to the current system virtualization time;

The second virtual markers updating block, be used for when this when scheduling of finishing when front port, if second time value of described timer record when front port is more than or equal to described default time delay value, the virtual end markers of described all empty queues in front port is set to the current system virtualization time, and with described timer zero clearing when front port;

Described when front port be a port in described a plurality of port, described very first time value is dispatched to described new connection and enters the blanking time of described empty queue from finishing the last time for described arbitrary port, and described second time value is describedly to be dispatched to described blanking time of finishing described this scheduling when front port from finishing the last time when front port.

The embodiment of the invention provides a kind of data communications equipment, comprises a plurality of communication port, also comprises above-mentioned scheduling multiport queues device, is used for described a plurality of communication port are carried out queue scheduling.

The scheduling multiport queues method and apparatus of the embodiment of the invention, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.

The annular of the time-delay of joining the team first that Fig. 1 produces when changing for ShVC dispatching algorithm middle port is schematic diagram relatively;

The flow chart of the scheduling multiport queues method that Fig. 2 provides for the embodiment of the invention one;

The flow chart of the scheduling multiport queues method that Fig. 3 provides for the embodiment of the invention two;

The flow chart of the scheduling multiport queues method that Fig. 4 provides for the embodiment of the invention three;

Annular when Fig. 5 joins the team for the new connection of the port A of the embodiment of the invention three under first kind of situation is schematic diagram relatively;

Annular when Fig. 6 joins the team for the new connection of the port A of the embodiment of the invention three under second kind of situation is schematic diagram relatively;

Annular when Fig. 7 joins the team for the new connection of the port A of the embodiment of the invention three under the third situation is schematic diagram relatively;

The structural representation of the scheduling multiport queues device that Fig. 8 provides for the embodiment of the invention four;

The structural representation of the scheduling multiport queues device that Fig. 9 provides for the embodiment of the invention five;

The structural representation of the data communications equipment that Figure 10 provides for the embodiment of the invention six.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment that is obtained under the creative work prerequisite.

The ShVC dispatching algorithm is a kind of typical PFQ dispatching algorithm, because it has the advantage of energy better controlled time delay and shake, and also also simple relatively in realization, therefore often be used in the CBR business of the atm network that delay performance is had relatively high expectations.As a kind of queue scheduling algorithm, the ShVC dispatching algorithm comprises several typical features:

1) adopt actual clock as system virtualization function of time V (t), V (t)=t, t＞0;

2) each grouping P _i ^kCalculate a virtual beginning markers S for it during arrival _i ^kWith virtual end markers F _i ^k, and computation rule is as follows:

$S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]---\left(1\right)$

$F_i^k=S_i^k+\frac{L_i^k}{r_i}---\left(2\right)$

Wherein, a _i ^kAnd L _i ^kK the grouping P of i lined up in expression respectively _i ^kThe time of advent and block length, r _iThe reserved bandwidth of i, F are lined up in expression _i ^K-1The virtual end markers of k-1 grouping among the i is lined up in expression.Virtual beginning markers S _i ^kBe the maximum in the virtual end markers of lining up k of an i actual time that arrives of grouping and a last grouping; Virtual end markers F _i ^kConcluding time for k the traffic packets of lining up i sends, be specially virtual beginning markers and add that the block length of this traffic packets is divided by reserved bandwidth;

3) the grouping selection strategy be minimum legal virtual end markers preferential (Smallest Eligiblevirtual Finished is called for short SEFF), and promptly in legal grouping, target divides into groups to send when preferentially selecting to have minimum virtual end.The legal grouping of indication herein, the virtual beginning markers that refers to grouping generally speaking is less than or equal to current system virtualization clock, that is:

$S_i^k<=V\left(t\right)---\left(3\right);$

4) when two or more virtual times being carried out the size comparison, for example state formula (1) in the use and calculate grouping P _i ^kVirtual beginning markers S _i ^k, to grouping P _i ^kActual time of arrival V (a _i ^k) and P _i ^kThe virtual end markers F of a last grouping _i ^K-1When carrying out the size comparison, use the difference comparative approach of annular comparator.The basic principle of this comparative approach is: at the count range of a virtual time function, in the i.e. dispatching cycle (potential), judge their size according to the difference between two time values, for example: if the difference of time value A and time value B is less than or equal to potential/2 (A-B＜=potential/2), then obtain the conclusion of A greater than B; If the difference of time value A and time value B is greater than potential/2 (A-B＞potential/2), then obtain the conclusion of A less than B.Therefore, between A and B, if one of them time value is fixed value, and another time value is when being variable value, if need to change the magnitude relationship of A and B, then value needs times of wait potential/2 at most regular time.Potential dispatching cycle herein is relevant with the minimum discharge of queue scheduling system, a packet scheduling cycle that specifically refers to the port of bandwidth minimum in the ShVC dispatching algorithm, it is required maximum duration of grouping of scheduling in the system, and in this dispatching cycle, at least one grouping team that will be scheduled out, and each port all will obtain dispatch service chance at least once.

Several essential characteristics based on above-mentioned ShVC dispatching algorithm, the basic implementation procedure of this algorithm generally comprises following several steps: when each grouping arrives some formations, utilize formula (1), (2) to calculate the virtual beginning markers and the virtual end markers of this grouping, and, wherein be designated as the virtual markers of this formation during the head grouping of each formation virtual with its storage; Before each scheduling, from all formations, select virtual end markers minimum and satisfied according to the SEFF principle $S_i^k<=V\left(t\right)$ The formation of condition+spend team; After finishing once scheduling, the virtual end markers of all formations is upgraded, carry out the scheduling of next round more again.

Based on above-mentioned basic implementation, because when the ShVC dispatching algorithm is carried out selection scheduling to all formations, the target size sorts during not only according to the virtual end of individual queue, but also the size of the current system virtualization time during with scheduling is relatively selected according to the virtual markers of each formation, further, after each finishing scheduling, also the virtual end markers of all formations is upgraded, make it follow current system time, such implementation makes the ShVC dispatching algorithm when the ATM switch of single port or atm router are used, can control its professional time-delay and shake that sends well, have good QoS performance.

But in the prior art, when the ShVC dispatching algorithm is applied to the ATM switch of multiport or atm router, because in any given moment, have only a port can obtain dispatch service, therefore do not have serviced port for other current, comprising formation can not obtain virtual end the time target upgrade in time, if and have new connection to join the team this moment in these formations, when the formation that i.e. connection newly enters is an empty queue, at this moment, should new connect the head that should be this formation and connect, the head grouping of this new connection then one be that the head of this formation divides into groups.Because there is not a grouping that is scheduled in this empty queue, and before new connection entered, its virtual end markers was not upgraded timely yet.Therefore, system is using formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}](k=1)$ Timestamp when calculating the virtual beginning of this new grouping for it is because F wherein _i ⁰Value do not exist, system need promptly be provided with a F for it for one last one virtual end markers of dividing into groups of this formation supposition _i ⁰Initial value.

The annular of the time-delay of joining the team first that Fig. 1 produces when changing for ShVC dispatching algorithm middle port is schematic diagram relatively.As shown in Figure 1, the time of an annular is represented a system dispatching cycle (potential), supposes a new real time V (a who arrives an empty queue that connects _i ^k) be V (t ₁), and the F that system is provided with for this empty queue _i ⁰Initial value be V (t ₀), at this moment, utilizing formula $S_i^1=\max [V\left(a_i^1\right),F_i^0]$ Timestamp when calculating the virtual beginning of this new grouping, need relatively just be V (t ₁) and V (t ₀) the value size.And according to the difference comparative approach of the annular comparator in the ShVC dispatching algorithm, the very possible initial value V (t that sets ₀) and V (t ₁) when comparing, in the more interval potential/2 of annular a higher value, V (t ₀)-V (t ₁)＜=potential/2 then obtains $S_i^1=V\left(t_0\right).$ Like this, when scheduler is dispatched the port at this formation place again, according to the feature 3 of above-mentioned ShVC dispatching algorithm), the virtual beginning markers S of this formation _i ¹Must satisfy V (t ₀The condition of)≤V (t) just can obtain dispatching out the chance of team, the current system virtualization time when wherein V (t) is for scheduling, supposes that this time is V (t ₂).Because in default, therefore each port all can obtain the minimum time T of a service opportunity generally for whole potential, is a smaller value, according to the difference comparative approach of the annular comparator in the ShVC dispatching algorithm, T is after the time for process, very likely V (t ₀) and V (t ₂) when comparing, still be a higher value at potential/2.At this moment, this new connection is if will dispatch out team, and the time that needs to wait for is at least | V (t ₀)-V (t ₂) |, and according to annular ratio juris relatively, at most even may reach for 1/2 cycle (potential/2) if this dispatching cycle that is provided with in system is chronic, should newly connect the delay time that needs to wait for this moment also will be very long this section period.And because this delay time is owing to system is that the virtual end markers irrational " excessive " that the new empty queue that connects before entering is provided with causes, so be an irrational delay time, can traffic affecting QoS performance.

Therefore, at the defective of above-mentioned ShVC dispatching algorithm on multiport is used, the embodiment of the invention has proposed a kind of array dispatching method and scheduler, for each port is provided with a timer, write down per two second phases of each port and face the blanking time of scheduling, and dispatching preceding and when having new connection to enter empty queue at every turn, by inquiring about the size of this blanking time, satisfy under the condition of a certain size value at it, correspondingly all empty queues in the current scheduling port and the new virtual markers of this formation that connects when entering are upgraded, thereby the time delay of joining the team first that will newly connect is controlled within the magnitude range of some settings, solved in the multiport application the new delay problem first that connects well.

The flow chart of the scheduling multiport queues method that Fig. 2 provides for the embodiment of the invention one, as shown in Figure 2, this method comprises:

Step 100, when having new connection to enter an empty queue in the arbitrary port in a plurality of ports, if the very first time of the timer record of this arbitrary port value is more than or equal to default time delay value, the virtual beginning markers of this empty queue is set to the current system virtualization time;

The scheduling multiport queues method of the embodiment of the invention is applied in the ATM switch or atm router of multiport, and the scheduler in this ATM switch or the atm router carries out dispatch service to wherein a plurality of ports jointly.At each current time, scheduler is only dispatched one of them port, and does not have a serviced port for current, is marked on the renewal that just can not obtain scheduler when service not being arranged during all formations that comprise in this port virtual.Therefore, under this kind situation, probably can take place when system be a new connection that enters empty queue timestamp when calculating virtual beginning markers and virtual end, at using formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ The time, the virtual end markers F of a last grouping that should newly connect wherein _i ^K-1It is the irrational initial value that system sets in advance for this empty queue, the virtual end markers of the new connection that calculates so also is an irrational value, thereby make that when scheduler reschedules this port this new connection need be waited for irrational delay time of growing team that just can be scheduled out.

Therefore, in the present embodiment, system all is provided with a timer for each port, this timer can be regarded as a time-delay computing unit to each port, finish when once dispatching at each port, its corresponding timer picks up counting, till this port is finished another time scheduling again.And in the present embodiment, when having new connection to enter an empty queue in any one port in a plurality of ports, no matter this port is current is the state that is in the service of being scheduled, still be in the state of the service of not being scheduled, scheduler all at first will be inquired about the current time value of the timer record of this port, in the present embodiment, claim that this current time value is a very first time value, this very first time value record this port be accomplished to this from last time scheduling and be carved with new connection and enter blanking time between two time points of this formation.Scheduler should be worth the very first time with in default time delay value carry out the comparison of size, and according to this comparative result decision is that the virtual beginning markers of this new connection is upgraded, obtain the virtual end markers of this new connection with this, still according to virtual beginning markers in the ShVC dispatching algorithm and virtual end markers computing formula, calculate the virtual markers of this new connection according to existing computational methods.The default time delay value of indication is each port of being provided with in the native system for the new connection acceptable of joining the team the first higher limit of time delay first herein.

Particularly, if scheduler is learnt by comparative result, this moment timer record very first time value during more than or equal to default time delay value, after when this represents that this port finishes scheduling from the last time the virtual markers of wherein formation being upgraded, there has been one long period empty queue wherein not to be upgraded, therefore if the new connection of an empty queue that enters this port this moment is the common computing formula that is provided with according to system, the virtual end markers that calculates probably is an irrational value, and according to above-mentioned to be scheduled out the analysis of time delay of team of new connection, this irrational virtual end markers probably makes, should new connect when being scheduled out group and can produce bigger time delay, need to wait for long delay time, and this is an irrational delay time.Therefore, in the present embodiment, the very first time value that scheduler one inquires timer record this moment is during more than or equal to the time delay value preset, just directly will be somebody's turn to do the new virtual beginning markers that connects upgrades, the virtual beginning markers that is about to this empty queue is set to the current system virtualization time, the phenomenon than the long delay time when avoiding its appearance to dispatch out group.

And learn by comparative result as if scheduler, the very first time of timer record this moment is worth less than default time delay value, after when this represents that this port finishes scheduling from the last time the virtual markers of wherein formation being upgraded, be carved with the empty queue that new connection enters this port to this, be not separated by a long period, also do not have long to making this new connection can produce situation appearance when being scheduled than long delay, and enter the new connection of an empty queue of this port this moment if the common computing formula that is provided with according to system, be designated as a reasonable value during the virtual end that calculates, can not cause the situation when this new connection occurs dispatching out group than the long delay time, therefore this moment, scheduler can not upgrade the virtual beginning markers of this new connection.

Thus, when an empty queue has new connection to join the team, no matter this empty queue is current is to be in just in serviced port, still being in does not have in the serviced port, as long as the interval of the time that the time that this new connection enters this empty queue and this port last time are scheduled has met or exceeded the new acceptable time of time delay first that is connected of system's setting, scheduler all can will should the new virtual beginning markers that connects upgrade, thereby make in the present embodiment, even new the connection when entering in the current empty queue that does not have a serviced port, under situation about satisfying condition, the formation at this new connection place also can obtain when virtual target and upgrade.

Step 101, when this when scheduling of finishing when front port, if when second time value of the timer record of front port more than or equal to default time delay value, work as that the virtual end markers of all empty queues is set to the current system virtualization time in the front port, and will work as the timer zero clearing of front port.

Need to prove, also can enter arbitrary port of an empty queue in one embodiment when front port in the step 101 for new connection is arranged in the step 100.

In the array dispatching method of multiport, the common all ports of scheduler carry out dispatch service, its according to the ratio of each port reserved bandwidth separately successively, circulation and between each port, changing liberally, wherein, the higher port of the reserved bandwidth volume of services and the scheduling times that obtain dispatching will be higher relatively also.For example, supposing to exist reserved bandwidth is the port A of 2M and two ports of port B that reserved bandwidth is 1M, when scheduler carries out dispatch service to these two ports, according to its reserved bandwidth separately, the chance that port A obtains dispatching should be 2 times of port B, promptly may port A be scheduled after 2 times, port B just is scheduled 1 time, therefore, the formation in port B may need to wait for more delay time than port A, and this delay time also should for port B self the delay time that should accept.

Therefore, for some fixed port, scheduler is unfixed to the blanking time between its adjacent twice scheduling of carrying out, possible scheduler is after the once scheduling that finishes port A, continuation is carried out next time scheduling operation to it, also might scheduler after having dispatched port A, in succession several other ports are carried out scheduling again and just come back to port A, at this moment, be far longer than the blanking time between twice scheduling in succession of port A the blanking time of adjacent twice scheduling of port A.Therefore the size of the blanking time of the adjacent scheduling of each port is not a fixed value, and it is according to the decision of reserved bandwidth separately of all related ports.

Therefore in the present embodiment, scheduler can access the blanking time of adjacent twice scheduling of each port according to the time value of the timer record of each port setting.This timer can be regarded as one of each port time-delay computing unit, finishes when once dispatching at each port, and its corresponding timer picks up counting, and finishes up to this port till the scheduling second time of this port.So, for each port, its corresponding timer all can be noted the blanking time of adjacent twice scheduling of this port, especially when the situation of scheduler from a port translation to the another port, the timer of that port that is converted picks up counting after scheduler finishes the last scheduling of this port before being converted, till scheduler is dispatched this port again.Therefore, no matter between this twice adjacent schedule periods, scheduler to what ports is dispatched again, time value during this period of time all will be got off by the timer record of this port, thereby when this port obtains the dispatcher meeting again, scheduler is by the time value of the current record of the timer of this port of inquiry, just can very clearly understand the time between twice scheduling in front and back of this port, thereby can be by judging the size of this conversion interval time, to in this port some because blanking time of Port Scheduling long, target is upgraded and is handled in the time of may causing the formation of non-essential time-delay to be carried out, and makes it to avoid producing long delay time.

Particularly, in the present embodiment, whenever scheduler to finish once scheduling when front port after, all will carry out and once search for renewal process this port, this search renewal process is specially: at first, read the current time value when the timer record of front port, in the present embodiment, claim that this current time value is second time value, this second time value be scheduler to the last time scheduling carried out when front port with this that carries out when front port dispatched between blanking time.Scheduler compares this second time value and default time delay value, if this time value is during more than or equal to default time delay value, and all formations in front port of scheduler traversal search, target renewal when virtual ends carried out in all empty queues wherein.Scheduler is connected when entering empty queue new in the default time delay value of indication and the step 100 herein, to be worth the very first time with a default time delay value compare the same, for each port in native system for the new connection acceptable of joining the team the first higher limit of time delay first, according to the actual demand of business, can carry out concrete setting to this time delay value.

Particularly, if scheduler is learnt according to comparative result, this moment timer record second time value during more than or equal to default time delay value, after when this represents that this port finishes scheduling from the last time the virtual markers of wherein formation being upgraded, there has been one long period empty queue wherein not to be upgraded.Therefore if this moment is to carrying out target renewal when virtual when the empty queue of front port, when after this empty queue have new connection to enter, scheduler is according to formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Timestamp when calculating the virtual beginning of this new connection, F wherein _i ^K-1Be one for a long time not obtain the value upgraded, may influence itself and the actual time of arrival V (a that should newly be connected _i ^k) big or small comparative result, thereby make that the virtual end markers of the new connection calculate like this also is an irrational value, and when scheduler reschedules this port, this new connection need be waited for irrational delay time of growing team that just can be scheduled out.Therefore, in the present embodiment, second time value that scheduler one inquires timer record this moment is during more than or equal to default time delay value, just directly will work as the virtual end markers of all empty queues of front port upgrades, the virtual end markers that is about to all empty queues in front port is set to the current system virtualization time, the phenomenon than the long delay time when avoiding its appearance to dispatch out group.

So, by the end of scheduler in each scheduling, it is the beginning of another time scheduling, all equal or exceed under the situation of default time delay value in very first time value when the timer record of front port, virtual end markers to wherein empty queue is upgraded, it is set to the current system virtualization time, make afterwards when new connection enters this empty queue first, timestamp when calculating the virtual beginning of this new connection, entered before this empty queue owing to should newly connect, scheduler can be regarded as the virtual end markers of a last grouping of this new grouping for the virtual end markers of this empty queue setting, and virtual end markers of a grouping is in the process that the residing port of this empty queue is being scheduled on this, is constantly upgraded to obtain.Therefore when after have new connection to enter this empty queue, scheduler passes through formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Timestamp when calculating the virtual beginning of this new connection, be to arrive in the preceding last renewal operation to this port with new connection, the virtual end markers of being somebody's turn to do a new last grouping that connects for the virtual end markers conduct of this empty queue setting calculates, be designated as a reasonable value during the virtual end that calculates this moment, can not cause the situation when this new connection occurs dispatching out group than the long delay time.

In addition, in the present embodiment, when scheduler to after having carried out upgrading when the virtual end markers of the empty queue of front port, the timer that also will deserve front port carries out zero clearing, make it to restart timing, timer begins to carry out the timing operation of a new round again like this, this scheduling of front port and the time interval between next scheduling worked as in record, so that scheduler before scheduling next time according to this record value, judge whether to wherein empty queue carry out virtual the end time target renewal again operate.

And if after the scheduling of carrying out a new round, scheduler searches this empty queue once more when searching for, promptly still not new this moment the connection enters this formation, and simultaneously the timer of this port through second time value of record this moment after the reclocking, met or exceeded default time delay value again again, at this moment, scheduler will upgrade the virtual end markers of this empty queue again, make it to follow again the current system virtualization time.And a certain formation that yet might work as front port simultaneously is not an empty queue after this scheduling, and by after another the scheduling, last grouping in this formation team that is scheduled out, therefore after the scheduling of a new round, this non-empty queue becomes empty queue, and at this moment, scheduler is being searched for this port in the process of renewal, as long as this moment timer record second time value more than or equal to default time delay value, scheduler can carry out when virtual target to this new empty queue equally and upgrade operation.

The scheduling multiport queues method that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

The flow chart of the scheduling multiport queues method that Fig. 3 provides for the embodiment of the invention two, as shown in Figure 3, this method comprises:

Step 200 has new a connection to enter an empty queue in the arbitrary port in a plurality of ports;

Particularly, in the present embodiment, the port that can be the current service of being scheduled of the arbitrary port indication in a plurality of ports can not have a serviced port for current yet.There are a plurality of formations in each port, wherein some is a non-empty queue, promptly have one or more connections successively in this formation, each has one or more groupings in connecting successively, waiting for and being scheduled, and also have partition queue element in each port is empty queue, promptly do not comprise any connection and grouping in this formation, in the last time scheduling that is grouped in this port in possible this formation, all dispatched out team in the scheduling several times perhaps, also might never have connection and grouping in this formation, any new connection enters into this formation, all is the first connection of this formation.Therefore, for an empty queue, in case there is new connection to enter, promptly have new grouping to enter, this a new grouping just head that is decided to be this formation is divided into groups, and therefore the virtual markers that should divide into groups just should be the virtual markers of this formation.

Step 201 is if the very first time of the timer record of arbitrary port value is more than or equal to default time delay value, execution in step 202, otherwise execution in step 203;

The same with described in the embodiment one, in the present embodiment, jointly a plurality of ports are carried out in the process of dispatch service at scheduler, for each port all is provided with a timer, this timer is finished when once dispatching from this port and is picked up counting, till it finishes another time scheduling once more, write down the blanking time between adjacent twice scheduling of each port.Therefore, in the present embodiment, when having new connection to enter an empty queue in any one port, no matter this port is current is the state that is in the service of being scheduled, still be in the state of the service of not being scheduled, scheduler all at first will be inquired about the current time value of the timer record of this port, in the present embodiment, claim that this current time value is a very first time value, this very first time value record this port be carved with new connection from last finishing scheduling to this and enter blanking time two time points of this empty queue; Scheduler should be worth the very first time with in default time delay value carry out the comparison of size, and judge at this empty queue according to this comparative result, target is upgraded during from this new connection last virtual before entering, being carved with new connection to this enters, whether at interval the long period, thereby whether decision will be to this new connection in view of the above, promptly target is carried out when virtual in this formation and upgrades operation.

Particularly, the default time delay value of indication is that system is provided with for each port is unified herein, and new connection is the maximum of time-delay first, and in the present embodiment, this default time delay value TMP should satisfy T _PortThe condition of≤TMP≤potential/2, wherein, T _PortRepresent the scheduler polls all of the port minimum time once, at a T _PortIn, all ports can both obtain service opportunity at least once; And potential is a system dispatching cycle, represent a packet scheduling cycle of the port of bandwidth minimum in all of the port, in the queue scheduling algorithm of the embodiment of the invention, when the difference comparative approach of the annular comparator that adopts carried out the size comparison to two virtual markers, an annular cycle of annular comparator was the time of a potential.Therefore, in this default time delay value TMP, in the present embodiment, each port all can obtain a dispatcher meeting at least.

Step 202 is upgraded the virtual beginning markers of this new connection, execution in step 204;

Particularly, if scheduler is learnt by comparative result, this moment timer record very first time value during more than or equal to default time delay value, after when this represents that this port finishes scheduling from the last time the virtual markers of wherein formation being upgraded, there has been one long period empty queue wherein not to be upgraded, therefore if the new connection of an empty queue that enters this port this moment is the common computing formula that is provided with according to system, the virtual end markers that calculates probably is an irrational value, and analysis according to the time delay of team that new connection is scheduled out, this irrational virtual end markers can produce bigger time delay when probably making this new connection be scheduled out group, needs to wait for long irrational delay time.Therefore, scheduler will upgrade the virtual beginning markers of this new connection this moment, directly be somebody's turn to do the new virtual beginning markers that connects and be set to the current system virtualization time, make $S_i^1=V\left(a_i^1\right),$ Promptly no longer pass through formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Calculate S _i ¹, but it directly is set to V (a by the mode of direct setting _i ¹).Such setting will be avoided when using formula calculates, and what calculate should new virtual beginning markers and the system virtualization time that connects unmatched situation occur.

Thus, when an empty queue has new connection to join the team, no matter this empty queue is current is to be in just in serviced port, still being in does not have in the serviced port, as long as the interval of the time that this new connection enters this empty queue with the concluding time that this port last time is scheduled met or exceeded the time delay value TMP that presets, scheduler all can be with should the new virtual beginning markers that connects directly be set to this new connection and enter this empty queue the time the system virtualization time, the virtual end markers of the new formation after making this new connection enter is followed the current system virtualization time, thereby make in the present embodiment, even new the connection when entering in the current empty queue that does not have a serviced port, this new connection also can obtain when virtual target and upgrade.And when this port obtains service opportunity again, because this port is at most in time T _PortIn can arrive once new dispatcher meeting, and this T _PortLess than being a value less than potential/2.Therefore for this new connection, according to the virtual beginning markers of following its current system virtualization time that enters empty queue of system for its setting, this virtual beginning markers and elapsed time T _PortAfter this port obtain once more dispatcher can the current scheduling time compare, difference comparative approach according to annular comparator, it must be a smaller value, thereby this newly be connected this port obtain once more dispatcher can the time, should satisfy " legal " condition in the SEFF grouping selection principle, current system virtualization time when promptly the virtual beginning markers that should newly connect is less than scheduling, scheduler can be dispatched out team with it in current scheduling, can not have time-delay.

Need to prove in addition, because in the present embodiment, the new connection of indication enters an empty queue and comprises two kinds of situations: this empty queue be specifically as follows a last dispatching cycle or in several dispatching cycles, scheduler is dispatched out team with last connection in this formation, do not include any connection in feasible this formation this moment, be an empty queue, promptly this kind situation specifically can be called as the situation of a breakpoint transmission; Also might enter first connection that newly is connected to this formation of this empty queue in addition this moment, promptly before this, not have the connection of any team that is scheduled out in this formation, this kind situation specifically can be called as a situation about connecting first.And no matter be to connect first or in the situation of breakpoint transmission, scheduler all can be according to value writing time of the timer of its port of living in, and target renewal when it is carried out virtual beginning does not have any difference in concrete operations.

Step 203 is calculated new virtual beginning markers and the virtual end markers that connects, execution in step 204 according to formula;

Particularly, if scheduler is learnt by comparative result, the very first time of timer record this moment is worth less than default time delay value TMP, after when this represents that this port finishes scheduling from the last time the virtual markers of wherein formation being upgraded, be carved with the empty queue that new connection enters this port to this, be not separated by a long period, also do not have long to making this new connection can produce situation appearance when being scheduled than long delay, and enter the new connection of an empty queue of this port this moment if the common computing formula that is provided with according to system, be designated as a reasonable value during the virtual end that calculates, can not cause the situation when this new connection occurs dispatching out group than the long delay time.Therefore this moment, scheduler can not upgrade operation to the virtual beginning markers of this new connection, but can be according to virtual beginning markers during with virtual end the target computing formula this new connection is carried out when virtual target and calculates.The target computing formula is the computing formula that defines in the ShVC dispatching algorithm when this virtual beginning markers and virtual end, is specially: $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}],$ $F_i^k=S_i^k+\frac{L_i^k}{r_i},$ Wherein, V (a _i ^k) be the system virtualization time when newly connection i enters this empty queue, F _i ^K-1Be the new virtual end markers that connects the last grouping of i in this empty queue, L _i ^kThe new block length that connects k the grouping of i of expression, r _iThe new reserved bandwidth that connects i of expression.

Step 204 is when front port is finished once scheduling;

Need to prove, also can enter arbitrary port of an empty queue in one embodiment when front port in the step 204 for new connection is arranged in the step 200.

Step 205, if when second time value of the timer record of front port more than or equal to default time delay value, execution in step 206 is if second time value is less than default time delay value, execution in step 207;

For the port that is being scheduled, finish when once dispatching, scheduler all will be carried out a search procedure to deserving front port, in this search procedure, scheduler will at first be inquired about the current time value when the timer record of front port, be referred to as second time value, and this second time value and default time delay value compared, it should default time delay value be each port acceptable of setting in advance of native system higher limit of time delay first, according to the actual demand of business, can carry out corresponding modification to this time delay value.Because this very first time value is for being dispatched to this value blanking time between dispatching when last time of front port.Scheduler can be learnt the time interval state that the virtual markers when all formations, the especially empty queue of front port is not updated from this comparative result, therefore can carry out different operations according to different comparative results.

To carry out size time delay value relatively the same with very first time value in the default time delay value of indication and the step 201 herein, and the system that is similarly is provided with for each port is unified, the maximum that new connection is delayed time first, and also similarly, this time delay value TMP that presets should satisfy T _PortThe condition of≤TMP≤potential/2, wherein T _PortRepresent scheduler polls all of the port minimum time once, at a T _PortIn, all ports can both obtain service opportunity at least once; Potential is a system dispatching cycle, represents a packet scheduling cycle of the port of bandwidth minimum in all of the port.

Step 206 is upgraded the virtual end markers of working as all empty queues in the front port, and the timer zero clearing that will work as the front port correspondence, execution in step 208;

If second time value of scheduler by relatively obtaining timer record this moment is more than or equal to default time delay value, representative is not carried out target renewal when virtual when the existing time period more than or equal to default time delay value of the empty queue in the front port, therefore if this moment is not to carrying out target renewal when virtual when the empty queue of front port, when after this empty queue have new connection to enter, scheduler is according to formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Timestamp when calculating the virtual beginning of this new connection, F wherein _i ^K-1Be one for a long time not obtain the value upgraded, may influence itself and the actual time of arrival V (a that should newly be connected _i ^k) big or small comparative result, thereby make that the virtual end markers of the new connection calculate like this also is an irrational value, and when scheduler reschedules this port, this new connection need be waited for irrational delay time of growing team that just can be scheduled out.So according to this judged result, scheduler will be worked as the virtual end markers of all empty queues in the front port and be upgraded, it is set to the current system virtualization time, and will work as the corresponding timer zero clearing of front port, makes it restart timing.And for the non-empty queue in front port, scheduler can not carry out the operation that any virtual markers is upgraded to it.

Thus, by the beginning of scheduler in each scheduling, all equal or exceed under the situation of default time delay value in very first time value when the timer record of front port, virtual end markers to wherein empty queue is upgraded, it is set to the current system virtualization time, make afterwards when new connection enters this empty queue first, timestamp when the virtual beginning of the new grouping of calculating this new connection, owing to should new grouping enter before this empty queue, the virtual end markers of this empty queue can be regarded as the virtual end markers of a last grouping of this new grouping, and virtual end markers of a grouping is in the process that the residing port of this empty queue is being scheduled on this, constantly upgraded and to be obtained, system virtualization time when it constantly follows each upgrade, be complementary with current system virtualization time.Therefore when after have new connection to enter this empty queue, scheduler passes through formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Timestamp when calculating the virtual beginning of this new connection, be to arrive in the preceding last renewal operation to this port with new connection, the virtual end markers of being somebody's turn to do a new last grouping that connects for the virtual end markers conduct of this empty queue setting calculates, be designated as a reasonable value during the virtual end that calculates this moment, can not cause the situation when this new connection occurs dispatching out group than the long delay time.

Need to prove in addition, the empty queue of indication herein comprises two kinds of situations: this empty queue was specifically as follows in a last dispatching cycle, scheduler is dispatched out team with last connection in this formation, does not include any connection in feasible this formation at the moment, is an empty queue; This empty queue also can enter for this formation never connects in addition, is an empty queue that does not have any connection and grouping always.And no matter be at which kind of situation, scheduler all can be according to when the value writing time of the timer of front port, and it is carried out when virtual target upgrades, and does not have any difference in concrete operations.

Step 207, the timer zero clearing that will work as the front port correspondence, execution in step 208;

If second time value of scheduler by relatively obtaining timer record this moment is less than default time delay value, then represent scheduler that target when front port hollow formation last virtual is upgraded distance and do not reach the predetermined time delay spacing time this moment, according to the virtual end markers of last time to the empty queue renewal of this port, calculate this empty queue when having new connection to enter, timestamp during the new virtual beginning that connects, can not cause the virtual end markers of empty queue to compare the new situation that to connect the actual system virtualization time that arrives be a very big value occurs, therefore this moment, scheduler need not carry out target renewal when virtual when the empty queue in the front port, the timer that only needs to work as front port carries out clear operation, make it to restart timing, so that scheduler before scheduling next time according to this record value, judge whether to wherein empty queue carry out virtual the end time target renewal again operate.

Step 208 according to the legal virtual end markers priority principle of minimum, selects the formation of virtual end markers minimum to dispatch.

When scheduler finishes after upgrading operation when the search before the once scheduling of front port, will be according to the SEFF grouping selection strategy that defines in the ShVC dispatching algorithm, in the virtual end markers according to each formation, selection is less than or equal to the formation of the end markers minimum current system virtualization time and virtual as carrying out the formation of dispatch service in this scheduling, a packet scheduling of this formation is gone out team, just finished scheduling operation one time.

And after this scheduling is finished, scheduler will begin work as the operation that front port is dispatched next time, search procedure before restarting next time to dispatch, and read size again when the timer of front port, compare with default delay value, target is upgraded when working as front port hollow formation virtual according to comparative result, promptly restarts to carry out the flow process of present embodiment.And the port when a front port and a last scheduling that this moment, scheduler was dispatched might be a port, also might be different port, if scheduler has carried out the conversion of port, port for the last time scheduling, its timing that will proceed timer adds up, till scheduler is dispatched it again.And in the process of scheduling, if other does not have serviced port this is carved with new connection when entering an empty queue, scheduler equally can be according to the timer time size this moment of judging this empty queue place port, target was upgraded when virtual beginning was carried out in this new connection, occurred to avoid this new long situation of time-delay when connecting group.

Need to prove in addition, in the present embodiment, when the arbitrary empty queue in arbitrary port of step 200～step 203 has new connection to join the team, when the current time of the timer record of this port value more than or equal to default time delay value, target operation when then upgrading the virtual beginning of this empty queue, promptly can be at scheduler by to second time value when the record of the timer of front port, target when virtual end is carried out in all empty queues of front port is upgraded operation carries out before, promptly can before step 204, carry out, carry out after also can comparing with default time delay value in the size of second time value of record that scheduler will be worked as the timer of front port, promptly also can after step 204, carry out, itself in addition can be in the present embodiment any one carry out constantly.Promptly in embodiments of the present invention, as long as new a connection when entering an empty queue arranged in a certain port, scheduler just can be carried out this operation, and the execution of this operation is not subjected to the restriction of time.And in the present embodiment, just listed a kind of embodiment, and for the technical scheme of the operating sequence that comprises other, as long as belong to the inventive concept of the embodiment of the invention, all within the scope that the embodiment of the invention is protected.

The scheduling multiport queues method that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

Since the embodiment of the invention specifically at be in multiport is used, for the current port that does not obtain dispatch service, when new connection enters an empty queue, the long problem of scheduler latency first that should newly connect, and can avoid the generation of above-mentioned situation for the scheduling multiport queues method that the embodiment of the invention is described more fully, in the following embodiments, is example with the spy with a certain concrete port A, describe when above-mentioned situation occurs the handling process of the scheduling multiport queues method of the embodiment of the invention in detail.

The flow chart of the scheduling multiport queues method that Fig. 4 provides for the embodiment of the invention three, as shown in Figure 4, this method comprises:

Step 300, when scheduler is finished when once dispatching port A, if second time value of the timer record of port A is more than or equal to default time delay value, scheduler upgrades the virtual end markers of all empty queues among the port A, and with the timer zero clearing of port A;

In the present embodiment, suppose that port A is the current scheduling port that scheduler carries out dispatch service, when scheduler finishes once scheduling to port A after, current time value with the timer record of read port A, in the present embodiment, the current time value of timer record is called second time value with this moment.After scheduler reads this second time value, the time delay value TMP of this second time value and systemic presupposition is compared, judge that port A finishes the back to the time delay value that whether has met or exceeded systemic presupposition blanking time the current finishing scheduling from last scheduled.This time delay value is the delay time first of the acceptable maximum that is provided with of system, is generally one less than 1/2 system dispatching cycle (potential/2), and greater than scheduler polls all of the port minimum time T once _PortTime value, therefore in the time range of this section time delay value representative, each port of system can both obtain a dispatcher meeting at least.If second time value of this moment is more than or equal to this default time delay value, scheduler is with traversal search all empty queues in front port A, and target is carried out when virtual in all empty queues upgrade, the virtual end markers of all empty queues is set to current system virtualization time V (t), and the timer with port A carries out zero clearing simultaneously, makes it begin reclocking.In the present embodiment, suppose that the system virtualization time at this moment is V (t ₁), promptly upgrading by this, scheduler all is updated to V (t with the virtual end markers of all empty queues that comprise this moment among the port A ₁).

Particularly, upgrade in the search procedure at this, scheduler searches to port A in empty queue may have two kinds of situations: this empty queue be specifically as follows this dispatching cycle or on once so that in dispatching cycle several times, scheduler is dispatched out team with last connection in this formation, not including any connection in feasible this formation at the moment, is an empty queue; This empty queue also can enter for this formation never connects in addition, is an empty queue that does not have any connection and grouping always.And no matter be at which kind of situation, scheduler all can be according to when the value writing time of the timer of front port A, and it is carried out when virtual target upgrades, and does not have any difference in concrete operations.

Step 301, scheduler are transformed into other ports from port A and carry out dispatch service;

In the present embodiment, suppose that scheduler finishes last scheduled to port A, and the virtual end markers of empty queue that will be wherein all upgrade finish after, be not to continue port A is carried out dispatch service again, carry out dispatch service but be transformed into other ports, promptly port A is not at this moment for there being one of serviced port.And in the present embodiment, though this moment, port A was not serviced, when system is the last scheduled end of the timer of its setting from port A, just be in the state of the timing that adds up always, there is new connection to join the team so that work as this port, when perhaps obtaining the dispatcher meeting again, scheduler can learn that from the current time value of this timer record this port finishes to the blanking time that has new connection to join the team from last scheduled, perhaps the blanking time between twice scheduling of this port.

Step 302, a new empty queue that connects entry port A, if the very first time of the timer record of port A value is more than or equal to default time delay value at this moment, the virtual beginning markers of this empty queue of scheduler is set to the current system virtualization time;

In the present embodiment, suppose during the port A service of not being scheduled, have one newly to connect an empty queue that enters wherein, and the hypothesis system virtualization time at this moment is V (t ₂), promptly be carved with a new empty queue that connects the entry port A to this from the last finishing scheduling of port A, at interval V (t ₂)-V (t ₁) time, and should blanking time the time value that timer write down of port A this moment just.Therefore, scheduler at this moment will be at first the current time value that this moment writes down of the timer of read port A, in the present embodiment, claim current time value this moment to be worth for the very first time, this very first time value record the blanking time the empty queue of port A from last finishing scheduling to this new connection entry port A.Read after the very first time value of timer record this moment, the time delay value that scheduler should be worth the very first time with systemic presupposition carries out size relatively, if very first time value is more than or equal to the time delay value of systemic presupposition, scheduler will be somebody's turn to do the new virtual beginning markers that connects the place formation and upgrade, be updated to the current system virtualization time, promptly be updated to V (t ₂), but the timer of port A is not carried out zero clearing this moment, the timer timing operation that still adds up.

Particularly, in the present embodiment, the acceptable maximum delay value of its of supposing the system setting is T, and because this time delay value TMP should be a time value less than 1/2 system dispatching cycle (potential/2), and in the present embodiment, in interpretation, suppose that this time delay value TMP is potential/4 for convenient.Therefore, for the virtual time V (t of the empty queue among this new connection entry port A ₂), in the present embodiment, specifically there are three kinds of situations in it:

First kind of situation, the annular when Fig. 5 joins the team for the new connection of the embodiment of the invention three middle port A under first kind of situation is schematic diagram relatively.As shown in Figure 5, the very first time of timer record is worth V (t at this moment ₂)-V (t ₁) less than TMP, therefore, scheduler does not upgrade operation to the virtual markers of this new connection, because this moment is when the virtual beginning markers computing formula of utilization $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Timestamp when calculating the virtual beginning of this new connection, this new connection arrives the real time V (t of empty queue ₂) with the last one virtual end markers of dividing into groups that should newly be connected, i.e. last one virtual end markers V (t of this empty queue ₁) compare, its difference must be a value less than potential/2, therefore passes through formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ The virtual beginning markers of the new connection of this that calculates also one is decided to be V (t ₂), follow the current system virtualization time, this moment, scheduler need not the virtual end markers of this new connection is upgraded operation.

And because in the time range of default time delay value TMP, each port can obtain dispatcher meeting once at least, A is no exception for port, therefore port A is at least after time of TMP, just can obtain a dispatcher meeting, suppose that the current system virtualization time when port A obtains the dispatcher meeting once more is V (t ₃), V (t ₃)-V (t ₂)≤TMP because this time delay value TMP is again a value less than potential/2 simultaneously, therefore this moment for this new connection, its virtual beginning markers V (t ₂) with the current system virtualization time V (t in when scheduling ₃) compare, one is decided to be a smaller value, promptly necessarily satisfies " legal " condition in the SEFF grouping selection strategy.Therefore, when port A obtained the dispatcher meeting once more, this new connection was as long as the virtual end markers minimum in port A, just team can directly be dispatched out, do not wait for time-delay and can not exist, for this new connection, the stand-by period of its team from joining the team to be scheduled out mostly is time T MP most;

Second kind of situation, the annular when Fig. 6 joins the team for the new connection of the embodiment of the invention three middle port A under second kind of situation is schematic diagram relatively.As shown in Figure 6, the very first time of timer record is worth V (t at this moment ₂V (the t of) '- ₁) more than or equal to TMP, and V (t ₂V (the t of) '- ₁)＜potential/2, promptly this moment V (t ₂) ' with V (t ₁Though) difference more than or equal to default time delay value TMP, use the difference comparative approach of annular comparator, V (t ₂) ' in certain annular is relatively in the interval, with V (t ₁) compare still higher value, therefore this moment, what obtain should the new virtual beginning markers that connects also should be V (t if the virtual beginning markers computing formula of utilization is calculated ₂) ', follows the current system virtualization time, and in the present embodiment, it directly is set to follow the current system virtualization time, promptly directly is set to V (t ₁Target correctness when) ', guaranteed this new virtual beginning that connects more, and do not conflict mutually with virtual beginning markers computing formula.

The same with last a kind of situation, because in the time range of default time delay value TMP, each port can obtain dispatcher meeting once at least, therefore port A is at least after time of TMP, just can obtain a dispatcher meeting, suppose that the current system virtualization time when port A obtains the dispatcher meeting once more is V (t ₃) ', V (t ₃V (the t of) '- ₂The TMP of) '≤because this time delay value TMP is again a value less than potential/2 simultaneously, therefore this moment for this new connection, its virtual beginning markers V (t ₂Current system virtualization time V (t during) ' with scheduling ₃) ' compare, same one is decided to be a smaller value, promptly necessarily satisfies " legal " condition in the SEFF grouping selection strategy.Therefore, when port A obtained the dispatcher meeting once more, this new connection was as long as the virtual end markers minimum in port A, just team can directly be dispatched out, do not wait for time-delay and can not exist, for this new connection, the stand-by period of its team from joining the team to be scheduled out mostly is time T MP most;

The third situation, the annular when Fig. 7 joins the team for the new connection of the embodiment of the invention three middle port A under the third situation is schematic diagram relatively.As shown in Figure 7, the very first time of timer record is worth V (t at this moment ₂) " V (t ₁) not only greater than TMP, and V (t ₂) " V (t ₁)＞potential/2, promptly this moment V (t ₂) " with V (t ₁) difference not only greater than default time delay value TMP, and use the difference comparative approach of annular comparator, V (t ₂) " in certain annular relatively in the interval, with V (t ₁) be in a ratio of a smaller value, therefore this moment, what obtain should the new virtual beginning markers that connects should be V (t if the virtual beginning markers computing formula of utilization is calculated ₁).This moment is not if upgrade the virtual beginning markers of this new connection, then because in the time range of default time delay value TMP, each port can obtain dispatcher meeting once at least, so time of passing through TMP again, port A can obtain a dispatcher meeting at least, supposes that the system virtualization time of this moment is V (t ₃) ", as shown in Figure 7, use the difference comparative approach of annular comparator obviously, probably can cause the virtual beginning markers V (t of this new connection ₁) obtain the moment V (t that dispatcher is understood with port A ₃) " be in a ratio of a higher value; promptly do not satisfy the condition of " legal " in the SEFF grouping selection strategy; even therefore this moment, port A obtained dispatcher meeting; do not satisfy the grouping selection strategy owing to should newly connect; can not be dispatched timely; thereby this newly is connected when obtaining the dispatcher meeting, its time-delay of dispatching out team still can need be waited for the delay time of time T MP at least at least greater than time T.

And in the present embodiment, as long as because when having new connection to enter an empty queue, just scheduler will be somebody's turn to do the new virtual beginning markers that connects in time and upgrade, therefore, in the case, the virtual beginning markers that scheduler will be somebody's turn to do connection newly directly is set to V (t ₂) ", follow the current system virtualization time, therefore when port A obtained the dispatcher meeting once more, the promptly current system virtualization time was V (t ₃) " time, because V (t ₃) " V (t ₂) "≤TMP because this time delay value T is again a value less than potential/2 simultaneously, therefore this moment for this new connection, its virtual beginning markers V (t ₂) " with the current system virtualization time V (t in when scheduling ₃) " compare, same one is decided to be a smaller value, promptly necessarily satisfies " legal " condition in the SEFF grouping selection strategy.Therefore, when port A obtained the dispatcher meeting once more, this new connection was as long as the virtual end markers minimum in port A, just team can directly be dispatched out, do not wait for time-delay and can not exist, for this new connection, the stand-by period of its team from joining the team to be scheduled out mostly is time T MP most.

Because above-mentioned three kinds of situations have comprised that port A is not when being scheduled, the all situations that the very first time value of timer record may occur when having new connection to enter wherein an empty queue, therefore, in the present embodiment, by concrete analysis to above-mentioned three kinds of situations, can draw, which kind of no matter newly be connected in the empty queue of entry port A under the situation, in the present embodiment, by in time its virtual beginning markers being updated to the current system virtualization time when entering, the time-delay first that should newly connect the team that is scheduled out can be controlled within the scope of default time delay value TMP in new the connection.

Step 303, scheduler are transformed into port A again and serve;

Be transformed into port A again when scheduler is its service, be port A obtain again dispatcher can the time, because in the step 302 of present embodiment, before port A is obtaining again dispatch service chance, scheduler has carried out when virtual target for the new connection that enters an empty queue this period to be upgraded, therefore when scheduler is transformed into port A again and serve for it, the virtual markers of newly dividing into groups in this new connection satisfies the SEFF selection strategy that divides into groups, and is a grouping that can be scheduled out team.

Step 304, scheduler select the formation of virtual end markers minimum among the port A to dispatch according to the legal virtual concluding time priority principle of minimum.

Scheduler is transformed into after port A serves again, will be according to the legal virtual concluding time priority principle of minimum, i.e. and SEFF grouping selection principle selects the formation of virtual end markers minimum among the port A to dispatch.In the present embodiment, unless in the time that port A does not obtain dispatching, promptly in step 302, have simultaneously in the empty queue of several new connections difference entry port A, make scheduler need successively it to be dispatched out team uniform this moment and be engaged in, and in this case, because the blanking time between each in succession scheduling is shorter, therefore, each new connection does not need to wait for the long period yet; Perhaps in port A, also there is the non-new grouping of the team that is not scheduled out in the last scheduled, and the probability that this situation occurs is very little, not so in this step, according to SEFF grouping selection principle, the condition of scheduling is satisfied in the new connection that enters this port A in the step 302, and the device selection scheduling in this scheduling that will be scheduled goes out team.And after this finishing scheduling, because this formation changes empty queue into from non-empty queue again, scheduler will be again carries out when virtual target according to the current time value of timer record to all empty queues among the port A and upgrades operation, prepares for dispatching next time.And in scheduling next time, scheduler may continue as port A service, also might be transformed into other port again, and no matter be which kind of situation, as long as target is upgraded when according to the array dispatching method of the embodiment of the invention formation that satisfies condition in each port being carried out, all will make the scheduling of new connections all in the native system go out the requirement that team satisfies time-delay.

Need to prove in addition, though present embodiment only is described and explains at the scheduling of port A, but the scheduling multiport queues method of present embodiment is applicable in all of the port in the multiport, promptly when scheduler is dispatched port A, in other ports in the present embodiment when new connection enters empty queue, target was upgraded operation when this new connection also will be carried out virtual beginning, equally, when the virtual beginning markers when scheduler is joined the team to the new connection of port A is upgraded, for the current port that just is being scheduled of scheduler, after each finishing scheduling, target renewal in the time of also will obtaining virtual ends of empty queue.Further, in the current scheduling port of scheduler, when new connection entered empty queue, scheduler can will should the new virtual beginning markers that connects upgrade equally.

The scheduling multiport queues method that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can be finished by the relevant hardware of program command, aforesaid program can be stored in the computer read/write memory medium, this program is carried out the step that comprises said method embodiment when carrying out; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CD.

The structural representation of the scheduling multiport queues device that Fig. 8 provides for the embodiment of the invention four.As shown in Figure 8, the scheduling multiport queues device of present embodiment comprises:

The first virtual markers updating block 11, be used for when having new connection to enter an empty queue in arbitrary port of a plurality of ports, if the very first time of the timer record of this arbitrary port value is more than or equal to default time delay value, the virtual beginning markers of this empty queue is set to the current system virtualization time;

The second virtual markers updating block 12, be used for when this when scheduling of finishing when front port, if when second time value of the timer record of front port more than or equal to default time delay value, work as that the virtual end markers of all empty queues is set to the current system virtualization time in the front port, and will work as the timer zero clearing of front port;

Wherein, in the above-mentioned second virtual markers updating block 12 when front port be one of them in a plurality of ports in the first virtual markers updating block 11, very first time value is dispatched to the blanking time that new connection enters an empty queue for arbitrary port from finishing the last time; Second time value is for being dispatched to the blanking time of finishing this scheduling when front port when front port from finishing the last time.

Wherein, the first virtual markers updating block, the second virtual markers updating block and the related concrete course of work that present embodiment is related, can not repeat them here with reference to the related content of the related embodiment exposure of above-mentioned scheduling multiport queues method.

The scheduling multiport queues device that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

The structural representation of the scheduling multiport queues device that Fig. 9 provides for the embodiment of the invention five.As shown in Figure 9, the scheduling multiport queues device of present embodiment comprises:

The first virtual markers updating block 11, be used for when having new connection to enter an empty queue in arbitrary port of a plurality of ports, if the very first time of the timer record of this arbitrary port value is more than or equal to default time delay value, the virtual beginning markers of this empty queue is set to the current system virtualization time;

The second virtual markers updating block 12, be used for when this when scheduling of finishing when front port, if when second time value of the timer record of front port more than or equal to default time delay value, work as that the virtual end markers of all empty queues is set to the current system virtualization time in the front port, and will work as the timer zero clearing of front port;

Wherein, in the above-mentioned second virtual markers updating block 12 when front port be one of them in a plurality of ports in the first virtual markers updating block 11, very first time value is dispatched to the blanking time that new connection enters an empty queue for arbitrary port from finishing the last time; Second time value is for being dispatched to the blanking time of finishing this scheduling when front port when front port from finishing the last time.

Particularly, the default time delay value of indication all is meant what system was provided with for each port is unified in the first virtual markers updating block 11 and the second virtual markers updating block 12, the new maximum of time-delay first that connects, and should should satisfy T by default time delay value TMP _PortThe condition of≤TMP≤potential/2, wherein, T _PortRepresent the once required minimum time of scheduler polls all of the port, potential represents a system dispatching cycle, is a packet scheduling cycle of the port of bandwidth minimum in the described all of the port.

Further, on the basis of the foregoing description four, the scheduling multiport queues device of present embodiment also comprises:

Virtual markers computing unit 13 is connected with the first virtual markers updating block 11, be used for if the very first time value of the timer record of arbitrary port less than the time delay value of presetting, according to formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Calculate the virtual beginning markers of this new connection, and according to formula $F_i^k=S_i^k+\frac{L_i^k}{r_i}$ Calculate the virtual end markers of this new connection;

Wherein, V (a _i ^k) be the system virtualization time when newly connection i enters an empty queue, F _i ^K-1Be the new virtual end markers that connects the last grouping of i, L _i ^kBe the new block length that connects k the grouping of i, r _iThe new reserved bandwidth that connects i of expression.

Timer zero clearing unit 14 is connected with the second virtual markers updating block 12, be used for if when second time value of the timer record of front port less than default time delay value, will work as the timer zero clearing of front port.

Queue scheduling unit 15, be connected with the second virtual markers updating block 12, virtual markers computing unit 13 and timer zero clearing unit 14, be used for being set to the current system virtualization time in the virtual end markers of working as all empty queues of front port, and will work as after the timer zero clearing of front port, according to the legal virtual concluding time priority principle of minimum, be SEFF grouping selection principle, select the formation of virtual end markers minimum in front port to dispatch.

Wherein, related all unit of present embodiment, with and the related concrete course of work, the related content that can disclose with reference to the related embodiment of above-mentioned scheduling multiport queues method does not repeat them here.

The scheduling multiport queues device that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion well, the requirement of variation.

The structural representation of the data communications equipment that Figure 10 provides for the embodiment of the invention six.As shown in figure 10, the data communications equipment of present embodiment comprises: be used to carry out a plurality of communication port 1 of data communication, and the scheduling multiport queues device 2 that is connected with communication port 1, be used for jointly a plurality of communication port 1 being carried out queue scheduling.

Particularly, data communications equipment in the present embodiment is specifically as follows an ATM switch or an atm router, and the composition structure of scheduling multiport queues device wherein with and the related concrete course of work, the related content that can disclose with reference to the related embodiment of above-mentioned scheduling multiport queues method and scheduling multiport queues device does not repeat them here.

The data communications equipment that the embodiment of the invention provides, by a timer is set for each port, when certain port obtains the dispatcher meeting and newly connection enters an empty queue, result according to the size of the timer of judging this port, wherein empty queue and the new virtual markers that connects this formation after entering are upgraded, make it follow the current system virtualization time, thereby will newly connect the time delay first of joining the team is controlled within the time range of setting, make the ShVC dispatching algorithm when ATM switch that is applied to multiport or atm router, time delay and jitter problem when individual queue is scheduled in the time of also controlling the multiport conversion have well guaranteed that more atm network CBR business was to the requirement of time delay and time delay variation when multiport was used.

One of ordinary skill in the art will appreciate that all or part of flow process that realizes in the foregoing description method, be to instruct relevant hardware to finish by computer program, described program can be stored in the computer read/write memory medium, this program can comprise the flow process as the embodiment of above-mentioned each side method when carrying out.Wherein, described storage medium can be magnetic disc, CD, read-only storage memory body (Read-OnlyMemory, ROM) or at random store memory body (Random Access Memory, RAM) etc.

It should be noted that at last: above embodiment only in order to technical scheme of the present invention to be described, is not intended to limit; Although with reference to previous embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, and perhaps part technical characterictic wherein is equal to replacement; And these modifications or replacement do not make the essence of appropriate technical solution break away from the spirit and scope of various embodiments of the present invention technical scheme.

Claims (11)

1, a kind of scheduling multiport queues method is characterized in that, comprising:

When having new connection to enter an empty queue in the arbitrary port in a plurality of ports, if the very first time of the timer record of described arbitrary port is worth more than or equal to default time delay value, the virtual beginning markers of described empty queue is set to the current system virtualization time;

Perhaps, when this when scheduling of finishing when front port, if second time value of described timer record when front port is more than or equal to described default time delay value, the virtual end markers of described all empty queues in front port is set to the current system virtualization time, and with described timer zero clearing when front port;

Described when front port be a port in described a plurality of port, described very first time value is dispatched to described new connection and enters the blanking time of described empty queue from finishing the last time for described arbitrary port, and described second time value is describedly to be dispatched to described blanking time of finishing described this scheduling when front port from finishing the last time when front port.

2, scheduling multiport queues method according to claim 1 is characterized in that, described default time delay value TMP satisfies T _PortThe condition of≤TMP≤potential/2, wherein, T _PortRepresent the once required minimum time of poll all of the port, potential represents a system dispatching cycle, and described system dispatching cycle is a packet scheduling cycle of the port of bandwidth minimum in the described all of the port.

3, scheduling multiport queues method according to claim 1 and 2 is characterized in that, also comprises:

If the very first time of the timer record of described arbitrary port, value was less than default time delay value, according to formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Calculate the virtual beginning markers of described new connection, and according to formula $F_i^k=S_i^k+\frac{L_i^k}{r_i}$ Calculate the virtual end markers of described new connection;

Wherein, V (a _i ^k) system virtualization time when entering described empty queue for described new connection i, F _i ^K-1Be the virtual end markers of the last grouping of described new connection i, L _i ^kBe k the block length of dividing into groups of described new connection i, r _iThe reserved bandwidth of representing described new connection i.

4, scheduling multiport queues method according to claim 1 is characterized in that, also comprises:

If second time value of described timer record when front port is less than described default time delay value, with described timer zero clearing when front port.

5, scheduling multiport queues method according to claim 1, it is characterized in that, described in the front port the virtual end markers of all empty queues be set to the current system virtualization time, and with described after the timer zero clearing of front port, also comprise:

According to the legal virtual concluding time priority principle of minimum, select described formation of working as virtual end markers minimum in the front port to dispatch.

6, a kind of scheduling multiport queues device is characterized in that, comprising:

The first virtual markers updating block, be used for when having new connection to enter an empty queue in arbitrary port of a plurality of ports, if the very first time of the timer record of described arbitrary port value is more than or equal to default time delay value, the virtual beginning markers of described empty queue is set to the current system virtualization time;

The second virtual markers updating block, be used for when this when scheduling of finishing when front port, if second time value of described timer record when front port is more than or equal to described default time delay value, the virtual end markers of described all empty queues in front port is set to the current system virtualization time, and with described timer zero clearing when front port;

Described when front port be a port in described a plurality of port, described very first time value is dispatched to described new connection and enters the blanking time of described empty queue from finishing the last time for described arbitrary port, and described second time value is describedly to be dispatched to described blanking time of finishing described this scheduling when front port from finishing the last time when front port.

7, scheduling multiport queues device according to claim 6 is characterized in that, described default time delay value TMP satisfies T _PortThe condition of≤TMP≤potential/2, wherein, T _PortRepresent the once required minimum time of poll all of the port, potential represents a system dispatching cycle, and described system dispatching cycle is a packet scheduling cycle of the port of bandwidth minimum in the described all of the port.

8, according to claim 6 or 7 described scheduling multiport queues devices, it is characterized in that, also comprise:

Virtual markers computing unit, be used for if the very first time value of the timer record of described arbitrary port less than the time delay value of presetting, according to formula $S_i^k=\max [V\left(a_i^k\right),F_i^{k-1}]$ Calculate the virtual beginning markers of described new connection, and according to formula $F_i^k=S_i^k+\frac{L_i^k}{r_i}$ Calculate the virtual end markers of described new connection;

Wherein, V (a _i ^k) system virtualization time when entering described empty queue for described new connection i, F _i ^K-1Be the virtual end markers of the last grouping of described new connection i, L _i ^kBe k the block length of dividing into groups of described new connection i, r _iThe reserved bandwidth of representing described new connection i.

9, scheduling multiport queues device according to claim 6 is characterized in that, also comprises:

Timer zero clearing unit, be used for if second time value of described timer record when front port less than described default time delay value, with described timer zero clearing when front port.

10, scheduling multiport queues device according to claim 6 is characterized in that, also comprises:

The queue scheduling unit, be used for being set to the current system virtualization time in described virtual end markers when all empty queues of front port, and with described after the timer zero clearing of front port, according to the legal virtual concluding time priority principle of minimum, select described formation of working as virtual end markers minimum in the front port to dispatch.

11, a kind of data communications equipment comprises a plurality of communication port, it is characterized in that, also comprises as the arbitrary described scheduling multiport queues device of claim 6～10, is used for described a plurality of communication port are carried out queue scheduling.

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