KR100772174B1 - Method for providing network time using timestamp of micro engine in line-card - Google Patents

Abstract

A method for providing network time of a line card by using a timestamp of a micro engine is provided to reduce a time error for forming the network time by the timestamp, by periodically correcting the relative time among the line cards connected to a statistical measurement server. A network system comprises an NTP(Network Time Protocol) server, a statistical measurement server for gathering statistics of packets and collecting measurement data, and multiple line cards for transmitting and receiving packet and control information to/from the statistical measurement server. A method for providing network time of the line card in the network system is composed of steps for receiving the packets from customers in each line card(S204); including a timestamp value provided from a micro engine embedded in each line card, to the received packet(S206); transmitting the packet to the statistical measurement server(S208); and obtaining the timestamp value included in the packet, in the statistical measurement server and setting the obtained timestamp value as the network time of the correspondent line card(S210).

Description

METHOD FOR PROVIDING NETWORK TIME USING TIMESTAMP OF MICRO ENGINE IN LINE-CARD}

1 is an exemplary configuration diagram of a network system to which the present invention is applied;

2 is a flowchart illustrating a method of providing network time of a line card using a time stamp of a micro engine according to an embodiment of the present invention; and

3 is a view showing a time calculation method using a time stamp according to the present invention.

Explanation of symbols on the main parts of the drawings

10: statistical measurement server 20: NTP server

30: Ethernet Network 40: Data Path

50: line card 51: time stamp

52: micro engine

The present invention relates to a method for providing network time of a line card. In particular, when a network time needs to be provided by a line card, the present invention can be implemented at low cost without complicated hardware logic by using a timestamp provided by a micro engine. The present invention relates to a network time providing method of a line card using a time stamp of a micro engine capable of providing time correction between each line card in a statistical measurement server.

In order to apply the internet pay-as-you-go system, it is necessary to provide statistics and network time of communication equipment. Currently, most line cards do not provide the network time of received packets.

In communication devices, it is important to measure the subscriber's network usage time and the number of packets. Also, the time the packet was received in the network is a major factor. In particular, in order to measure the reception time of the packet and the usage time of the subscriber in the equipment processing the data flow of the subscriber, it is necessary to provide the network time of receiving the packet from the line card. However, the micro engine responsible for the data path of the line card does not have the resources to provide network time, and it is difficult to add external devices and logic when using a commercial micro engine. In addition, the connection with the interface for providing standard vision such as Global Positioning System (GPS) is also complicated and difficult to implement.

There are two conventional methods for providing network time of equipment for collecting packet measurement and statistical data in a line card processing a high speed packet. That is, a method of adding a hardware time receiver such as GPS to an external additional logic and a method of setting the arrival time of a packet received by a statistical measurement server. However, the former hardware method has difficulty in adding expensive and complicated logic, and the latter method of processing a server receives packets according to packet processing time between line cards when multiple line cards are operated. The disadvantage is that it is not possible to determine the fair relative time between multiple line cards because the order can vary.

Conventionally, as a technology for implementing network synchronization, Korean Patent Laid-Open Publication No. 2004-56981 (published on July 1, 2004) discloses a system and method for implementing synchronization of a network using a synchronous mobile terminal as an external reference clock. have. In addition, Korean Patent Laid-Open Publication No. 2004-50151 (published on June 16, 2004) discloses a method of implementing time synchronization of an exchange through an external Ethernet matching unit. However, the above patents do not provide a method of providing network time to a line card by using a time stamp value provided by the micro engine of the line card, and do not suggest a method of correcting time deviation between a plurality of line cards.

Therefore, there has been a demand in the technical field for developing a technology that sets the network time of a line card, which operates as an important factor, of packet reception time for traffic specification and billing, etc. more easily and at low cost.

As a solution to the above-mentioned conventional problems, the first object of the present invention is to provide a network time of a received packet using a timer used as a time stamp in the micro engine of each line card, thereby providing additional hardware or logic. The present invention provides a method of providing network time of a line card using a micro engine time stamp that can be implemented at low cost.

In addition, a second object of the present invention is to perform a periodic time correction from the NTP server in the statistical measurement server for the time correction of the time stamp between each line card, and for the time stamp interval of the line cards according to the correction period The present invention provides a method for providing a network time of a line card using a time stamp of a micro engine to calculate a deviation to correct a relative time between line cards.

Network time providing method of the line card using the time stamp of the micro-engine according to the present invention for achieving the above object,

In a network system including an NTP (Network Time Protocol) server, a statistical measurement server for collecting packet statistics and measurement data, and multiple line cards for transmitting and receiving packets and control information with the statistical measurement server,

Receiving a packet from a subscriber in each of the line cards; A second step of including in the received packet a timestamp value provided by the micro-engine embedded in each line card; Transmitting the packet to the statistical measurement server; And a fourth step of acquiring a time stamp value included in the packet from the statistical measurement server and setting the network time of the corresponding line card.

In one embodiment of the invention, the second step preferably sets the timestamp value to metadata of the received packet.

In one embodiment of the present invention, prior to the first step, receiving a network base time from the NTP server at the statistical measurement server; And setting the received network reference time as an initial time of each line card.

In an embodiment of the present invention, after the fourth step, storing the obtained time stamp value at the statistical measurement server; Calculating a deviation value of an average of the difference between the currently stored time stamp value and the immediately stored time stamp value; And resetting the network time of the corresponding line card using the deviation value in the statistical measurement server. In this case, the steps are preferably performed according to a preset correction period of the network time.

In one embodiment of the present invention, the network time reset is preferably reset to the reference time set from the NTP server at the statistical measurement server + timestamp value of the received packet + deviation value.

In the following, a detailed description of a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, when it is determined that detailed descriptions of related well-known functions or constructions may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted so as not to obscure the subject matter of the present invention. will be.

1 is an exemplary configuration diagram of a network system to which the present invention is applied.

Referring to FIG. 1, in the network system 100 to which the present invention is applied, the statistical measurement server 10 is connected to an NTP (Network Time Protocol) server 20 in an NTP protocol in a client / server structure. The NTP is defined in Internet Standard 12 and RFC 1119 as a network time protocol for accurately maintaining time on the Internet. In addition, the statistical measurement server 10 and the plurality of line cards 50 transmits the control information and the measurement packet through the Ethernet network (30). Each line card 50 provides a data path 40 through a switch fabric or network. The statistical measurement server 10 sets and synchronizes network time from the NTP server 20, and the line card 50 provides a timestamp 51 to provide the network time of packets received from the network. ) And transmits the time and statistical information of the packet to the statistical measurement server (10). The statistical measurement server 10 always has a constant network time from the NTP server 20, and sets the time stamp of the line card 50 to the time of the statistical measurement server 10 in advance.

At this time, each line card 50 has a built-in micro engine (ME) (52) for processing packets. The micro engine (ME) uses a timestamp (51) using a timer that is synchronized with the clock of the micro engine to perform a quality of service (QoS) function such as metering and scheduling. to provide. The time stamp is increased in accordance with the synchronous clock of the line card 50. The increased time is periodically corrected by the statistical measurement server 10. In order to correct the time, the time value of the line card must be reset, and in order to reset the time, the function of the micro engine of the line card must be stopped. Therefore, the time correction of the line card 50 is performed only in the statistical measurement server 10.

Accordingly, the present invention is to provide a network time using the time stamp provided by the timer that most micro engines are built in. In this way, the timestamp setting function using the timer provided in the micro engine (ME) of the existing line card without expensive complicated hardware logic is used as network time for statistical measurement.

2 is a flowchart illustrating a method of providing a network time of a line card using a time stamp of a micro engine according to an embodiment of the present invention.

2, the network time of the statistical measurement server 10 from the NTP server 20 is set (S200). At this time, the statistical measurement server and NTP server (10,20) operates in a client-server structure. The statistical measurement server 10 sets a network base time set from the NTP server 20 as a preset time value of each line card 50 (S202). The initial time value is set to a time at which the timestamp driving starts after being initialized in advance before enabling the timestamp.

Subsequently, it is determined whether a packet is received at each of the line cards 50 (S204). If a packet is received at each of the line cards 50, the time stamp value provided by the micro engine of the line card is provided to the received packet. It includes (S206). More preferably, the micro engine of the line card 50 sets a time stamp value in the structure of metadata of the received packet. The timestamp time of the first received packet and the timestamp time of the last received packet in each flow of the received packet are maintained in a predetermined flow table. This information is information for calculating the network usage time of the subscriber. Furthermore, statistical information for calculating the number of packets and the number of bytes received for each flow of the packet is also maintained in the flow table. From this information, the data usage of the subscriber can be calculated, and the network efficiency and performance of the network equipment can be calculated.

As described above, the line card transmits the packet in which the time stamp value is set to the statistical measurement server 10 (S208). The statistical measurement server 10 obtains a time stamp value from the packets transmitted from the respective line cards 50 and sets the network time of the corresponding line card 50 (S210).

On the other hand, since the functions provided for each of the line cards 50 are not the same and a slight error may occur in the change of the time stamp value according to each characteristic, in order to provide relative reliability between the line cards 50, It is desirable to readjust the actual time stamp value according to the deviation value of the stamp value. However, since the timestamp value reset of each line card must be executed after the function of the micro engine is stopped, it is difficult to perform the continuous function of the apparatus. Therefore, when the statistical measurement server 10 collects the time stamp value from the received packet, it is necessary to correct the actual network time according to the deviation value of the time stamp value.

Accordingly, the statistical measurement server 10 collects a current time stamp value (new timestamp: n_ts) from each of the line cards 50 at the current period according to a preset network correction period. (S210), the time stamp value (old timestamp: o_ts) immediately before the collected in the last cycle is stored (S212). The variance of the time stamp value of each line card 50 is calculated using the current time stamp value n_ts collected in the current cycle and the time stamp value o_ts immediately before collected in the previous cycle (S214). . That is, the deviation value of the average value with respect to the difference (n_ts-o_ts) between the current timestamp value n_ts and the immediately preceding timestamp value o_ts is calculated. The deviation value represents the degree of change with respect to the average value of the time stamp values of the current and previous time of each line card 50. The collection of the timestamp value of the line card and the calculation of the variance are repeatedly performed at every correction period of the network time until a packet is received by the line card (S210).

Subsequently, the statistical measurement server 10 recalculates the timestamp value of the packets collected from the respective line cards 50 into actual network time (S216), and the recalculated each line card 50. The network time of each line card 50 is set using the timestamp value of (S218). In this case, the actual timestamp value of the received packet is recalculated by adding the timestamp of the received packet and the deviation value calculated as described above to a preset time value at which the timestamp starts to be driven. The recalculated result is calculated as a time value for the number of clocks of the micro engine of each line card 50.

3 is a view showing a time calculation method using a time stamp of the present invention.

Referring to FIG. 3, a method of calculating a time stamp value according to the present invention as an actual time will be described. The timestamp according to the present invention is 64-bit driven by two registers, 32-bit high and low. Therefore, the value of the timestamp is a combination of two register values. The micro engine is driven to increase the time stamp value every 16 micro engine cycles in order to provide a longer time than the 64-bit value, and rolls back to zero when the value of the time stamp is 'OxFFFFFFFFFFFFFFFF'. -back). However, the time to return to zero is enormous, so it doesn't go back to zero while the machine is in use. If we set the clock value equal to the performance of the micro engine to be P, one cycle is 1 / P second. Thus, the time the packet was received on the line card is (timestamp value x 16 / P) seconds.

The drawings and detailed description of the invention are merely exemplary of the invention, which are used for the purpose of illustrating the invention only and are not intended to limit the scope of the invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, it is possible to provide network time at low cost without additional hardware or logic by providing network time of received packets using a timer used as a time stamp in the micro engine of each line card.

In addition, according to the present invention it is possible to reduce the time error to implement the network time as a time stamp through the periodic time correction between all line cards connected to the statistical measurement server.

Claims (6)

In a network system including an NTP (Network Time Protocol) server, a statistical measurement server for collecting packet statistics and measurement data, and multiple line cards for transmitting and receiving packets and control information with the statistical measurement server, Receiving a packet from a subscriber in each of the line cards; A second step of including in the received packet a timestamp value provided by the micro-engine embedded in each line card; Transmitting the packet to the statistical measurement server; And A fourth step of acquiring a time stamp value included in the packet by the statistical measurement server and setting the network time of the corresponding line card; Network time providing method of the line card using the time stamp of the micro engine comprising a. The method of claim 1, wherein the second step, And setting the time stamp value in metadata of the received packet. The method of claim 1, wherein before the first step, Receiving a network base time from the NTP server at the statistical measurement server; And Setting the set network reference time as an initial time of each line card; Network time providing method of the line card using the time stamp of the micro-engine further comprising a. The method of claim 1, wherein after the fourth step, Storing the obtained timestamp value at the statistical measurement server; Calculating a deviation value of an average of the difference between the currently stored time stamp value and the immediately stored time stamp value; And Resetting the network time of the corresponding line card using the deviation value in the statistical measurement server; Network time providing method of the line card using the time stamp of the micro-engine further comprising a. The method of claim 4, wherein Wherein the steps are executed according to a preset correction period of the network time. The method of claim 4, wherein the network time, The network time providing method of the line card using the time stamp of the micro-engine, characterized in that reset to the reference time set from the NTP server + the time stamp value of the received packet + the deviation value in the statistical measurement server.

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