A kind of method that in Ethernet, realizes differentiated service model QoS
Technical field
The present invention relates to Differentiated Services building block technique field, be specifically related to a kind of method that in Ethernet, realizes differentiated service model QoS.
Background technology
In broadband network, QoS (Quality of Service, professional quality assurance) is a very important notion.The parameter of QoS comprises: time delay (delay), delay variation (delayjitter), Loss Rate (lossrate), bandwidth (bandwidth) etc., and different business can require network that different qos parameters is provided, and wherein, the most basic is bandwidth.
Broadband network need utilize various QoS mechanism, to reach following several objects:
1), preferentially guarantees high-grade user's bandwidth to the user of different brackets.
2) to the user of same grade, guarantee that each user enjoys the bandwidth of its reservation, whether the part that exceeds reservation has remaining bandwidth to determine whether abandoning according to network.
3) have under the situation of remaining bandwidth at network, distribute remaining bandwidth according to each user's qos requirement.
Broadband network is made of a plurality of network equipments usually, as shown in Figure 1.At present, there are two kinds of methods can realize the QoS of whole network.
Method one: each equipment in the network all identifies all users, and the qos parameter according to the user carries out QoS processing, promptly so-called Integrated Services model then.
Method two: only on user's access device, identify the user, and carry out qos parameter at the user and handle, stamp different marks such as user's priority and reserved bandwidth that whether flow exceeds the user etc. according to result to customer flow simultaneously.Other equipment then only need carry out QoS according to the mark of flow and handle promptly so-called Differentiated Services model.The access device here is meant the direct-connected equipment with the user, and in Fig. 1, equipment 1 is the access device of domestic consumer 1.
Because the extension of network that Integrated Services model is unfavorable for is so broadband network selects for use Differentiated Services model to realize the QoS of whole network usually.
Concerning Differentiated Services model, service traffics need the mark mode that the whole network is unified.In the 802.1p agreement, when ethernet frame carries VLAN TAG, can carry precedence information by the user_priority among the VLAN TAG (User Priority) territory.
The form of VLAN TAG as shown in Figure 2.
Among Fig. 2, VLAN TAG is made up of two bytes, and wherein, the highest 3bit of first byte is user_priority, and User_priority is used to represent the priority of customer service, and the priority corresponding relation of the priority of customer service and equipment is as shown in table 1.
Table 1
In the table 1, Number of available Traffic Classes refers to the supported priority number of equipment.Content representation in the table 1: when equipment is only supported a priority, 0 to 7 these 8 all corresponding these priority of coding of user_priorty; When equipment is supported 2 priority, 0~3 corresponding device priority, 0,4~7 corresponding device priority 1s of user_priorty; When equipment is supported 3 priority, 0~3 corresponding device priority, 0,4~5 corresponding device priority 1s of user_priority, 6~7 corresponding device priority 2s; When equipment was supported 4,5,6,7,8 priority, the rest may be inferred.
In the labeling method of above-mentioned service traffics, user_priority can only represent the priority of customer service, can not represent whether service traffics have exceeded user's reserved bandwidth.Because in the broadband network, whether equipment can only perception have remaining bandwidth with the link that it directly links to each other, and can not understand other links in real time whether remaining bandwidth is arranged also, therefore, access device is when carrying out the QoS processing to customer flow, with the link that it directly links to each other whether remaining bandwidth is arranged, all must abandon whole promise breaking flows, promptly abandon the flow that exceeds user's reserved bandwidth.Otherwise next stage equipment is not having can to adopt the mode of random drop to the flow of same priority under the situation of remaining bandwidth, thereby causes the promise breaking flow to tie up the situation of legitimate traffic.
With Fig. 1 is example, sets all link bandwidths and is 10M, and the reservation flow of all advanced level users all is 5M.The actual flow of advanced level user 1 is 10M, and the actual flow of advanced level user 2 is 5M.Because equipment 3 can not recognize the user, can only random drop 5M flow, the possibility of result is that two users respectively are dropped 2.5M, this is inequitable to advanced level user 2.
For avoiding above-mentioned situation to occur, access device is when carrying out the QoS processing to customer flow, with the link that it directly links to each other whether remaining bandwidth is arranged, all must abandon whole promise breaking flows, so, even remaining bandwidth is arranged in the network, the user also can only enjoy the bandwidth of its reservation, and this method is unfavorable for making full use of of Internet resources.
802.1ad revised the definition of user_priority, user_priority is renamed as PCP (Priority CodePoint, precedence level code territory), increased the definition of Discard Enable among the PCP, the definition of PCP is as shown in table 2.
Table 2
In the table 2, it is 8P0D, 7P1D, 6P2D, 5P3D that PCP can have 4 kinds of coded systems, and equipment need determine to support any coded system by configuration.For example, when equipment is supported 6P2D, express support for 6 priority, wherein 2 priority are supported Discard Enables, promptly PCP is 2,3 o'clock, is same priority 2, and simultaneously, permission equipment at first abandons PCP when remaining bandwidth is not enough be 2 flow.
Above-mentioned coded system more complicated is unfavorable for that equipment realization QoS handles.
Summary of the invention
The objective of the invention is to, a kind of method that realizes differentiated service model QoS in Ethernet is provided,, simplified the coding method of VLAN TAG, make QoS be easy to realize by using the Discard Enable position of 1 bit.
For achieving the above object, a kind of method that realizes differentiated service model QoS in Ethernet provided by the invention comprises:
A, the Discard Enable position of 1 bit is set;
B, access device are provided with the Discard Enable position of customer service according to user service flow amount and this user's primary bandwidth;
C, miscellaneous equipment judge whether all service traffics that need to send surpass bandwidth;
If surpass, from the customer service that the Discard Enable position is set to allow to abandon, choose and discarding traffic;
If be no more than, send the business that all need send; Described miscellaneous equipment is the network equipment that need proceed to transmit to the user traffic that described access device transmits except that described access device.
Described step a specifically comprises:
1 bit in the user_priority/PCP territory of VLAN TAG is set to the Discard Enable position.
Described step a also comprises:
All the other 2 bits are set to the user priority level in the user_priority/PCP territory of VLAN TAG.
Described step b specifically comprises:
Access device is monitoring the user service flow amount when being no more than this user's primary bandwidth, and the Discard Enable position of customer service is set to forbid abandoning.
Described step b specifically comprises:
Access device is monitoring the user service flow amount when surpassing this user's primary bandwidth and being no more than predetermined high bandwidth thresholding, and the Discard Enable position of customer service is set to allow to abandon.
Described method also comprises:
Access device abandons this customer service monitoring the user service flow amount when surpassing predetermined high bandwidth thresholding.
Described bandwidth comprises: the maximum bandwidth that described miscellaneous equipment can provide.
Described method also comprises:
Provide the excess bandwidth order business according to the Discard Enable position.
The charging policy of the different excess bandwidths in the described excess bandwidth order business is different with the charging policy of primary bandwidth.
Description by technique scheme as can be known, the present invention identifies this professional Discard Enable by adopt 1 bit in user service flow, as utilize the Discard Enable that 1 bit comes identification service of fixing in the user_priority/PCP territory among the VLAN TAG, simplified the coding method of VLAN TAG, made miscellaneous equipment can determine the Business Stream that can be dropped easily; Allow to abandon by being designated, each user's primary bandwidth can be fully guaranteed above the user traffic flow of primary bandwidth; The present invention utilizes this Discard Enable potential energy enough in the user provides bandwidth over-booking business, and can provide different tariff policy with different excess bandwidths for user's primary bandwidth, has enriched professional kind; Access device among the present invention is by carrying out dual rate monitoring to the user service flow amount, will surpass the service traffics of being scheduled to high bandwidth thresholding and directly abandon, and guaranteed that further each user can rationally use network bandwidth resources; Thereby realized simplification QoS implementation procedure by technical scheme provided by the invention, improved professional multifarious purpose.
Description of drawings
Fig. 1 is the broadband network schematic diagram;
Fig. 2 is the form schematic diagram of VLAN TAG;
Fig. 3 is the QoS implementation method flow chart in the differentiated service of the present invention.
Embodiment
Core of the present invention is: the Discard Enable position that 1 bit is set, access device is provided with the Discard Enable position of customer service according to user service flow amount, this user's primary bandwidth, miscellaneous equipment carries out business according to the value of the Discard Enable position of carrying in the customer service and abandons when determining to need discarding traffic.
Based on core concept of the present invention technical scheme provided by the invention is further described below.
Miscellaneous equipment among the present invention for except that access device need be to the user traffic network equipment proceeding to transmit of access device transmission, in Fig. 1, for advanced level user 1, equipment 1 is its access device, 3 of equipment are miscellaneous equipments.
Access device of the present invention at first need be provided with the Discard Enable position of 1 bit in user's business, this Discard Enable position can be arranged among the VLAN TAG, as takies 1 fixed bit position in the user_priority/PCP territory.
The user_priorty/PCP territory comprises three bits altogether, the present invention uses one of them fixing bit to represent Discard Enable, this fixing bit is the Discard Enable position, the different values of Discard Enable position can be used to expression and allow to abandon, forbid abandoning, as value is that 0 expression allows to abandon, and value is that 1 expression is forbidden abandoning.
Allow to abandon when being illustrated in miscellaneous equipment and needing discarding traffic, this business can at first be dropped, as with link that this miscellaneous equipment is connected on when not having remaining bandwidth, the business that other this equipment at first should abandon is: the Discard Enable position is set to allow the business that abandons.When forbidding abandoning the equipment of being illustrated in and needing discarding traffic, this business can not be dropped.
Two bits of in the user_priority/PCP territory all the other are represented service priority, and these two bits can be supported 4 priority at most, and each priority is all supported Discard Enable.
Operator can utilize this to encode and realize user bandwidth over-booking business (Overbooking), this business can be under the prerequisite of the primary bandwidth that guarantees the user, allow the user to use the excess bandwidth of some, but, do not guarantee the availability of this part excess bandwidth, promptly do not have under the situation of remaining bandwidth at network, this part flow will at first be dropped.
By bandwidth Overbooking is provided for the user business, operator can realize tariff policy more flexibly, as with the size of user's primary bandwidth as the basic grade of chargeing, on this basic grade basis, can determine different charging policy according to the quantity of excess bandwidth, promptly operator can be provided with different rate for user's primary bandwidth, different excess bandwidths.
Describe below in conjunction with 3 pairs of QoS implementation methods of the present invention of accompanying drawing.
Among Fig. 3, all be configured to support the mode of Discard Enable coding in step 300, with access device and miscellaneous equipment.
Receive the user service flow amount to step 310, access device.
To step 320, access device the user service flow amount is carried out the dual rate monitoring, judge that promptly whether the user service flow amount surpasses its primary bandwidth, whether surpasses predetermined high bandwidth thresholding, if the user service flow amount surpasses predetermined high bandwidth thresholding, to step 321, directly these service traffics are abandoned.
In step 320, if surpassing primary bandwidth, the user service flow amount do not surpass predetermined high bandwidth thresholding, to step 322, the corresponding bits position that the Discard Enable position of these service traffics is set to allow to abandon as in the user_priority/PCP territory is set to 0.Then, these service traffics are transferred to miscellaneous equipment.To step 330.
In step 320, if the user service flow amount does not surpass primary bandwidth, to step 323, the Discard Enable position of these service traffics is set to forbid abandoning, and is set to 1 as the corresponding bits position in the user_priority/PCP territory.Then, these service traffics are transferred to miscellaneous equipment.To step 330.
In step 330, other equipment are judged the Business Stream of its reception, definite needs send to the maximum bandwidth whether service traffics on the link can provide less than this link, promptly judged whether remaining bandwidth, if remaining bandwidth is arranged, to step 331, all Business Streams of its reception are all sent on the link.
In step 330, if there is not remaining bandwidth, to step 332, at first from the Business Stream that the Discard Enable position is set to allow to abandon, choose the Business Stream that need abandon, be set to 0 Business Stream as the corresponding bits position that at first abandons in the user_priority/PCP territory, then, the Business Stream that abandons of maximum bandwidth that can provide according to link and the needs chosen carries out business and abandons.
Describe below in conjunction with 1 pair of QoS implementation method of the present invention of accompanying drawing.
Equipment 1 to equipment 6 all is configured to support the mode of Discard Enable coding among setting Fig. 1, and equipment 1 to equipment 6 is all supported 2 kinds of customer service priority.All link bandwidths are 10M among Fig. 1, and the bare flow of all advanced level users all is 5M, and advanced level user 1 has registered bandwidth over-booking business, and excess bandwidth is 5M, and the actual flow of advanced level user 1 is 10M, and the actual flow of advanced level user 2 is 5M.Predetermined high bandwidth thresholding in equipment 1, the equipment 2 is 15M.
The service traffics of 1 pair of advanced level user 1 of equipment are carried out the dual rate monitoring, because the actual flow of advanced level user 1 is 10M, surpass its primary bandwidth, but do not surpass high bandwidth thresholding, so, the Discard Enable position that equipment 1 should surpass the service traffics of primary bandwidth part is set to allow to abandon, and is set to 0 as the corresponding bits position in the user_priority/PCP territory.
The service traffics of 2 pairs of advanced level users 2 of equipment are carried out the dual rate monitoring, because the actual flow of advanced level user 2 is 5M, do not surpass its primary bandwidth, so, the Discard Enable position of the service traffics of equipment 2 advanced level users 2 is set to forbid abandoning, and is set to 1 as the corresponding bits position in the user_priority/PCP territory.
Equipment 3 receives the service traffics of advanced level user 1 and advanced level user 2, because the high bandwidth that can provide in the link of equipment 3 is that the bandwidth sum of the service traffics of 10M and advanced level user 1 and advanced level user 2 is 15M, so, equipment 3 needs discarded part separate service flow, at this moment, the Discard Enable position of equipment 3 advanced level users 1 service traffics that are set to allow abandon, surpass the primary bandwidth part abandon.Thereby, guaranteed the primary bandwidth of advanced level user 1 and advanced level user 2.
Though described the present invention by embodiment, those of ordinary skills know, the present invention has many distortion and variation and do not break away from spirit of the present invention, and the claim of application documents of the present invention comprises these distortion and variation.