WO2008104100A1 - An apparatus and a method for realizing flow control based on rate restrict for mstp device - Google Patents

Abstract

An apparatus and a method for realizing flow control based on rate restrict for MSTP device implement flow monitoring to the input or output data flow mainly by use of Policing module, and transmit flow control signal to the distant end device when the data flow capacity exceeds the flow control threshold, decrease the input data flow capacity, so as to avoid the packet loss due to the rate restrict in the present device. By implementing flow control to the output data, with the aid of the marking function for service flow, the flow control function for Ethernet layer 2 pause frame port and the flow control for the particular service on layer 3 in Ethernet can be realized, and the service damage caused by output queue congestion is prevented. The invention can ensure the undamaged transmission for the packet-based service data flow in network, provide the detection and report for service bandwidth, and satisfy the flow capacity control requirement for the particular service when Ethernet service is transported on the MSTP transmission device.

Description

 Device and method for implementing flow control based on rate limitation on MSTP device

Technical field

 The present invention relates to a multi-service transport platform (MSTP) transmission device in a communication system, and more particularly to an apparatus and method for implementing flow control based on rate limiting on an MSTP transmission device. Background technique

 In the data network of a communication system, the flow control (ie, flow control) function is a commonly used function. The access processing of service data such as Ethernet and ATM (Asynchronous Transfer Mode) is supported on the MSTP device. For Ethernet applications, the MSTP device can rate the input data. When the Ethernet data accessing the MSTP device exceeds the negotiated rate, the service data exceeding the bandwidth is discarded; or when the Ethernet data accessing the MSTP device is In the sending direction, the output queue is congested due to the unscheduled scheduling. To prevent the output queue from being congested, traffic control is implemented by sending a Layer 2 PAUSE flow control frame to the remote device. That is, the data flow has two aspects of ingress traffic monitoring and egress queue monitoring in the MSTP device.

 In the traditional flow control mode, when implementing FIFO or queue-based flow control, FIFO controlled flow control supports service lossless processing, usually to the source port under the MAC FIFO fast full condition or under the egress queue fast full condition (data flow) The input port) sends a flow control frame. In the prior art, ingress traffic monitoring can be enabled or disabled, i.e., in terms of rate limiting, there can be input rate limiting or no input rate control. When there is rate control, only bandwidth control can be implemented: Packets with input data bandwidth excess are discarded and service is damaged. Also, the flow control mechanism and rate limiting are completely isolated and not associated with each other. This is because rate control is implemented at the ingress. Packet loss and flow control frame triggering are not associated due to rate limiting, and traffic may be corrupted.

 The current input rate limiting method is damaging to the service and cannot guarantee the integrity of the service data. Summary of the invention

1 180600164 The technical problem to be solved by the present invention is to provide an apparatus and method for implementing flow control based on rate limiting on an MSTP device, which is used to solve the problem that the data packet is discarded due to the bandwidth limit of the input data in the prior art, and the rate limit is If there is no association with the flow control frame, it may cause damage to the service, and implement accurate and complete traffic control for the guaranteed service.

 The present invention provides a device for implementing flow control based on rate limiting on a multi-service transmission platform device, which is characterized in that it comprises a data input module, a flow classification module, a Policing module, a queue management/scheduling module, and a data output module which are sequentially connected in sequence. And a management control module for controlling and connecting to the above module, wherein

 a data input module, configured to receive an input data stream;

 The flow classification module allocates a flow label for the input data stream according to the flow classification rule and determines a corresponding output queue, and simultaneously transmits the flow label to the management control module, and sends the data stream carrying the label to the flow classification module.

Policing module;

 The management control module sets the Policing control parameters according to the agreed rules, including a speed limit threshold for rate control and a flow control threshold for flow control;

 The Policing module performs traffic monitoring on the received data according to the flow label transmitted by the flow classification module and the protocol policy parameter of the flow label transmitted by the management control module, and when the input data traffic is greater than the flow control threshold, the remote device The node sends a flow control frame indicating that the input data traffic is reduced; when the output data traffic is greater than the speed limit threshold, discarding the corresponding data packet or marking the data packet as the violation data, and outputting the data flow to the queue management/scheduling module;

 The queue management/scheduling module manages and schedules the admitted data, discards the data packet marked as the violation data, performs the queue processing of the data packet marked as normal data, and sends the data packet to the corresponding output port for output;

 The data output module is configured to output the normal data stream according to the processing result of the queue management/scheduling module.

 The device further includes:

 The data encapsulation and EOS processing module is connected to the queue management/scheduling module for detecting the status of the SDH channel. When the number of members of the virtual concatenation VCG changes, the real-time bandwidth information of the SDH channel of the VCG is Give management control module;

2 180600164 The flow control frame triggering module is connected to the policy module, and triggers a corresponding flow control frame according to the monitoring result of the specific service flow label by the policy module;

 The MAC control module completes the transmission and reception control of the data packet on the Ethernet interface.

 Further, the policy control parameter set by the management control module includes: a rate limit threshold for rate control, and a data rate Vd and a packet burst length Ld including a trigger rate control when configured as a single leaky bucket parameter , when configured as double leaky barrel parameters, Vdmax/Ldmax and Vdmin/Ldmin;

 The flow control threshold for flow control includes a data rate Vc for triggering flow control and a packet burst length Lc when configured as a single leaky bucket parameter;

 Wherein, the burst length of all the data packets should satisfy one condition: greater than the maximum packet length allowed by the data stream.

 Further, in the Policing module:

 When the input data traffic is less than or equal to the flow control threshold, stopping sending a flow control frame indicating that the input data traffic is reduced to the remote device node;

 When the remote device does not respond to the flow control frame, it performs traffic monitoring on the output data. When the rate limit threshold is configured as a single leaky bucket parameter (Vd, Ld), if the output data flow rate is greater than the speed limit threshold value Vd, Then discard the corresponding data packet or mark the data packet as red to indicate the violation data, no shell ' J , mark the data packet as green to indicate normal data, output data flow to the queue management / scheduling module; the speed limit threshold is configured as double leak When the bucket parameters Vdmax/Ldma and Vdmin/Ldmin are used, when the monitored traffic data traffic does not violate the agreed low threshold parameters (Vdmin, Ldmin), the packet is marked as green; when the monitored traffic data traffic exceeds the agreed low threshold parameter (Vdmin) , Ldmin), but not exceeding the agreed high threshold parameter (Vdmax, Ldma), the packet is marked in yellow;

 When the service data traffic exceeds the agreed high threshold parameter (Vdmax, Ldmax), the data packet is marked in red or the data packet can be directly discarded.

 The color tag of the packet is passed to the queue management/scheduling module.

 Further, in the queue management/scheduling module:

3 180600164 The drop control parameters of the queue include two types: a low threshold Lh for half full and a high threshold Lf for fast full; when receiving a received data packet, the received data packet marked with red is directly discarded, and is marked as yellow/green. The receiving packet performs the following processing depending on the queue status:

 When all packet sizes in the queue are less than the queue low threshold Lh, the packets enter the queue. When all packet sizes in the queue are greater than the queue low threshold Lh but less than the queue high threshold Lf, the packets marked in green are queued, marked yellow. Packets are discarded;

 When all packet sizes in the queue are greater than the queue high threshold Lf, all newly received packets are discarded.

 Further, the data encapsulation and the EOS processing module are reported to the management control module when the bandwidth of the virtual concatenation group VCG is smaller than the flow control threshold, and the management control module modifies the policy module according to the actual bandwidth of the virtual concatenation group VCG. The flow control threshold is such that it is less than or equal to the actual bandwidth of the virtual concatenation group VCG.

The present invention further provides a method for implementing flow control based on the foregoing apparatus, comprising the following steps: (1) The flow classification module allocates a corresponding flow label to the input data stream according to the flow classification rule, determines an output queue of the input data packet, and reports the same at the same time. The flow label to the management control module;

 (2) The Policing control parameter is set by the management control module for the service corresponding to the flow label according to the agreed rule, including a flow control threshold for flow control, and a speed limit threshold for the rate limit;

 (3) The Policing module performs traffic monitoring on the service data carrying the flow label according to the policy control parameter negotiated by the management control module. When the input data traffic is greater than the flow control threshold, traffic control is started, and the remote device node is sent to the remote device node for sending a flow control frame indicating a decrease in input data traffic;

 (4) When the remote device does not respond to the flow control frame, the policy module monitors the service data carrying the flow label according to the policy control parameter negotiated by the management control module. When the output data rate is greater than the speed limit threshold, the label is marked. The data packet is the violation data; otherwise, it is marked as normal data, and the marked data packet is forwarded to the queue management/scheduling module;

 (5) The queue management/scheduling module manages and schedules the accepted data, and discards the data packet marked as the violation data according to the tag information of the received data packet, and marks the packet as a normal number.

4. 180600164 The data packets are processed into the queue and dispatched to the corresponding output port.

 Further, the steps of configuring the Policing control parameter in step (2) are:

 The speed limit gate P艮 value for rate control is configured, and when configured as a single leaky bucket parameter, the data rate Vd and the packet burst length Ld of the trigger rate control are included, which is Vdmax/ when configured as a double leaky bucket parameter. Ldma and Vdmin/Ldmin;

 Configure a flow control threshold for flow control, which includes a data rate Vc for triggering flow control and a packet burst length Lc when configured as a single leaky bucket parameter;

 Wherein, the burst length of all the data packets should satisfy one condition: greater than the maximum packet length allowed by the data stream.

 Further, step (3) can be further divided into:

 Traffic monitoring is performed on the input data stream according to the flow label delivered by the flow classification module and the protocol Policing parameter of the flow label transmitted by the management control module:

 When the input data traffic is greater than the flow control threshold value Vc, sending a flow control frame indicating that the input data traffic is reduced to the remote device node;

 When the input data traffic returns to less than or equal to the flow control threshold value Vc, the flow control frame indicating that the input data traffic is reduced is stopped from being sent to the remote device node.

 Further, step (4) can be further divided into:

 Traffic monitoring is performed on the output data according to the flow label delivered by the flow classification module and the protocol Policing parameter of the flow label transmitted by the management control module:

 When the speed limit threshold is configured as a single leaky bucket parameter (Vd, Ld), if the output data traffic is greater than the speed limit threshold Vd, the corresponding data packet is discarded or the data packet is marked red to indicate the violation data. Mark the packet as green to indicate normal data, and output data to the queue management/scheduling module; when the speed limit threshold is configured as double leaky bucket parameters Vdmax/Ldmax and Vdmin/Ldmin, if the monitored traffic data traffic does not violate the agreement Low threshold parameters (Vdmin, Ldmin), marking the packet as green; if the monitored traffic data traffic exceeds the agreed low threshold parameter (Vdmin, Ldmin) but does not exceed the agreed high threshold parameter (Vdmax, Ldmax), the packet marking Yellow

5 180600164 If the service data traffic exceeds the agreed high threshold parameter (Vdmax, Ldmax), the data packet is marked in red or the data packet can be directly discarded.

 Pass the color tag of the packet to the queue management/scheduling module.

 Further, the step (2) further includes the step of configuring a discarding control parameter of the queue, where the configured queue discarding control parameter includes: a low threshold of a half full Lh and a high threshold of a fast full Lf;

 Correspondingly, in the step (5), the queue management/scheduling module discards the received data packet marked in red when processing the received data packet, and performs the following processing according to the queue status by the received data packet marked as yellow/green:

 When all packet sizes in the queue are less than the queue low threshold Lh, the packets enter the queue. When all packet sizes in the queue are greater than the queue low threshold Lh but less than the queue high threshold Lf, the packets marked as green are queued, marked as Yellow packets are discarded;

 When all packet sizes in the queue are greater than the queue high threshold Lf, all newly received packets are discarded.

 Further, the method further includes the following steps:

 If the data encapsulation and the EOS processing module are used as the output, if the bandwidth of the virtual concatenation group VCG is smaller than the flow control threshold, the management control module is reported, and the management control module modifies the policy module according to the actual bandwidth of the virtual concatenation group VCG. The flow control threshold is such that it is less than or equal to the actual bandwidth of the virtual concatenation group VCG.

The traffic control of the specified bandwidth flow can be implemented by using the technical solution of the present invention: when the data traffic exceeds the flow control threshold, the flow control signal is sent to the remote device, and the remote device receives the flow control frame and reduces the data traffic, thereby avoiding the present Packet drops on the device due to rate limiting. Through the tagging function of the service flow, the flow control function of the Layer 2 pause frame port of the Ethernet and the flow control of the specific service of the Layer 3 can be implemented to prevent the service queue from being damaged due to the output queue congestion.

 The present invention optimizes the traffic control policy in the MSTP transport network, ensures the packet-free service data flow in the network, and provides the service bandwidth detection and reporting, so that the operator can grasp the operation status of the service on the network and make the city The traffic control policy of the local area network is more complete, which satisfies the specific service flow control requirements of the Ethernet service on the MSTP transmission equipment. Through bandwidth and flow control

6 180600164 System, which reduces the occupation of resources by abnormal services, prevents business damage, and improves network transmission quality. BRIEF abstract

 1 is a functional block diagram of an MSTP device in an embodiment of the present invention;

 2 is a schematic diagram of service processing of a device for implementing flow control based on rate limiting according to an embodiment of the present invention;

 3 is a flow chart of performing flow control in an embodiment of the present invention;

 4 is a flow chart of processing a rate parameter for adjusting flow control in an embodiment of the present invention.

Preferred embodiment of the invention

 The specific implementation of the technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

 In this embodiment, the main ideas for implementing flow control based on rate limiting are as follows:

 When the received data traffic detected by the receiving module of the MSTP device exceeds its agreement, the flow control frame is fed back to the remote device (instead of discarding the ultra-bandwidth service); the remote device is notified to reduce the input to the MSTP. The data traffic of the device to implement traffic-based port-based or traffic-based bandwidth control to prevent service transmission damage.

 In addition, in the direction of the Ethernet to the optical synchronization network (ETHERNET -> SDH), when the EOS module in the sending direction of the MSTP device is in the direction of the link, the bandwidth of the service channel is reduced, and the Policing module of the device adjusts the link to the Ethernet. The network inputs the flow control bandwidth parameter of the service flow, and when detecting that the input service data flow bandwidth exceeds the set output flow control bandwidth parameter, the flow control frame is fed back to the remote device to perform bandwidth control of the service data. At the same time, the actual bandwidth of the link can be reported in real time through the management interface.

In this embodiment, a device for implementing flow control based on rate limiting on an MSTP device is provided, and a hardware functional block diagram thereof is shown in FIG. 1 , which mainly includes: a data input module, a flow classification module,

Policing module, queue management/scheduling module, data output module, and a management control module. among them:

7 180600164 1) Data input module, which includes MAC, EOS processing module, that is, data input interface. Used to receive an input service data stream from the outside, and send the service data stream to the stream classification module;

2) The flow classification module allocates flow labels and output queues for the business data stream input from the outside according to the agreed rules.

 In the flow classification module, the input service data packets need to be matched according to the agreed rules (ie, the flow classification rule), the service data flow is classified and identified, and the data packets that meet the agreed rules are marked with corresponding flow labels, and the The flow label is passed to the management control module. The processing of the flow classification module further includes determining a forwarding destination output queue of the input data packet.

 The convention is the traffic classification rule. For the Ethernet service, it can be, but is not limited to, port/port+VLAN/port+VLAN+DSCP/port+VLAN+802.1P, etc., which is used to distinguish the flow of user services (that is, according to the above information). Generate a flow label, which is the flow definition method of the business). The above agreed rules are all existing general techniques.

 3) The management control module provides a configuration management interface, the management controls the data input/output module, the flow classification module, the Policing module, the queue management/scheduling module, and controls the data flow and the queue parameters according to the flow label of the service data flow. And information reporting, such as configuring the control parameters of the policy, including flow control thresholds for flow control, speed limit thresholds for rate limiting, and information processing such as VCG bandwidth monitoring.

 The management control module sets the protocol Policing control parameters of the service data flow corresponding to the service corresponding to the flow label according to the agreed rule, including the data rate V and the packet burst length L:

 – the class is the rate rate controlled data rate Vd and the packet burst length Ld, which is the rate limit threshold for rate limiting;

 One is the data rate Vc that triggers flow control and the packet burst length Lc, which is the flow control threshold used for flow control;

 In various parameter setting modes, the burst length L of the data packet should satisfy one condition: It is greater than the maximum packet length allowed by the data stream.

 4) The Policing module performs traffic bandwidth monitoring according to the Pocling control parameters (mainly rate parameters) set by the management control module and performs rate control or transmission of flow control frames according to service traffic.

 When the Policing module receives the data packet, it receives the data flow label ID according to the flow classification module.

8 180600164 And the management policy parameter of the flow label transmitted by the management control module, performs traffic monitoring on the data flow, and performs corresponding processing according to the traffic monitoring result (determination of default):

 When the input service data traffic exceeds the set flow control threshold, the traffic control frame is sent to the service source node to notify it to reduce the input data rate to reduce the input traffic;

 When the output service data traffic exceeds the set speed limit threshold, the data of the default is discarded.

/ or mark processing, the marked 3⁄4: packet is sent to the queue management / scheduling module.

 5) The queue management/scheduling module allocates queues according to the output port and priority according to the flow label, performs queue management and scheduling, and sends the data packet to the corresponding sending port. After receiving the data, the queue management/scheduling module performs an inbound or discarding process on the incoming data packet according to the tag information of the data packet and the resource usage status of the target queue corresponding to the data packet. At the same time, the scheduling of the data packets in the queue is also performed, and the data packets are sent to the corresponding output port (Ethernet port or EOS port).

 6) The data output module, including the MAC control module, the EOS module, etc., is used to output the data packet to the corresponding port.

Referring to FIG. 2, the apparatus for implementing flow control based on rate limiting according to the embodiment may further include:

 The data encapsulation and EOS processing module is used to check the status of the SDH channel. When the number of members of the VCG changes, the real-time bandwidth information of the SDH channel of the VCG is reported to the management control module.

 The flow control frame triggering module triggers the corresponding flow control frame according to the monitoring result of the Policing module on the specific service flow label.

 The MAC control module completes the transmission and reception control of the data packet on the Ethernet interface.

Based on the combination of the modules in the hardware configuration shown in FIG. 1, as shown in FIG. 2, a flow diagram showing the flow control processing of the input data stream according to the configuration is performed, and the rate and flow control of the input data of one Ethernet port are performed. Finally, the output is sent through the VCG port.

 The demand is the service data accessed by the Ethernet port, and the allowed service guaranteed bandwidth is

9 180600164 30M, the peak bandwidth is 35M, the VCG bandwidth is 30M, the VCG output is encapsulated in GFP, and the virtual concatenation supports the LCAS protocol. Proceed as follows:

 A, ^^ According to the service configuration, the flow classification module assigns a flow label ID to the received data of the Ethernet port, and specifies an output queue, a flow control/rate limiting protocol policy parameter, a VCG member configured in the management control module to configure a flow label ID. And working mode configuration, etc.

 Al, the Policing parameter of the management control module agreement includes two parameters, the agreed data rate V and the protocol burst length L. In this embodiment, two types of Policing parameters are corresponding:

 The Policing parameter of the flow control is used to trigger the flow control frame to limit the input bandwidth. The rate control Policing parameter is used to limit the transmission bandwidth in the output direction.

 For the Policing parameter of rate control, depending on the type of service, the single leaky bucket or double leaky bucket can be used to control the parameters. The single leaky bucket parameter is Vd/Ld. The parameters of the double leaky bucket are Vdmax/Ldmax and Vdmin/Ldmin, where the monitoring bandwidth corresponding to Vdmax and Ldmax is large, corresponding to the burst bandwidth of the high threshold parameter; the monitoring bandwidth corresponding to Vdmin and Ldmin is small, and the guaranteed bandwidth corresponding to the low threshold parameter . In this embodiment, Vdmax = 35M and Vdmin = 30M. At the time of output, the output traffic can be monitored using the rate-controlled Policing parameter, and the corresponding processing strategy is applied to the default packet based on the traffic monitoring result.

 For the Policing parameter of flow control, the single leaky bucket parameter: Vc/Lc is used, and compared with the low threshold parameter (guaranteed bandwidth) with small monitoring bandwidth in the rate control Policing parameter. The parameter setting methods are listed below:

 a. The data rate of the trigger rate control is equal to the data rate of the trigger flow control.

(Vd=Vc), the burst length of the trigger rate control packet is greater than the burst length of the packet that triggers the flow control (Ld>=Lc:), which can be configured as: · Vd=Vc-30M, Ld=Lc=64 kbytes ;

 b. The data rate of the rate control is greater than the data rate of the flow control (Vd>Vc), and the burst length of the trigger rate control is equal to the packet burst length (Ld=Lc) that triggers the flow control. Can be configured as: Vd = 30M / Vc = 29M, Ld = Lc - 64kb tes.

 c. The data rate of the rate control is greater than the data rate of triggering flow control (Vd>Vc), and the burst length of the trigger rate control is greater than the burst length of the trigger flow control (Ld>Lc). It can be configured as: Vd=30M/Vc=29M, Ld=64kbytes/Lc=60kbytes.

10 180600164 A2. The traffic classification module specifies an output queue for the service of the flow label ID: the queue corresponds to the output VCG port. Multiple priority queues can be set under the VCG port. The drop control parameters of the queue include two types: a low threshold Lh for half full and a high threshold Lf for fast full. When the data packet capacity in the queue is greater than the corresponding capacity, the new input data packet performs corresponding operations according to its color label. For the corresponding processing operation, refer to C2.

B. As shown in Figure 3, the Policing module monitors the traffic data traffic with the flow label ID (including the monitoring of the input data stream and the output data stream) according to the leaky bucket algorithm, and performs corresponding operations according to the monitoring result.

 Bl. When the service data violates the Policing parameter (Vc, Lc) for flow control, the flow control starts. In full-duplex mode, the PAUSE flow control frame is periodically sent to the remote device connected to the Ethernet port of the device through the MAC to notify the remote device to reduce the data traffic. When the monitored traffic data of the flow tag ID does not violate the protocol policy. When the parameters (Vc, Lc), the PAUSE flow control frame is stopped.

 The "violation" described here means that the actual rate of the data stream exceeds the data rate Vc in the Policing parameter. Through the flow control frame processing mechanism, the actual traffic/bandwidth of the received service data can be effectively controlled. The flow control frame enters the highest priority transmission queue to ensure the real-time performance of the PAUSE flow control frame transmission. The content of the PAUSE flow control frame is standard. The flow control frame has timestamp information, which defines the time at which the remote end stops transmitting the data frame after receiving the PAUSE frame. The PAUSE frame timestamp value sent by the device is 0, indicating that the current flow control process ends.

 B2. If the remote device does not respond to the flow control frame sent by the local device, the data traffic of the local end may continue to increase. In this case, the output bandwidth limit of the Policing module takes effect to ensure normal operation of the device and the network. See process B3 for the process.

 B3. The Policing module traverses the data stream of the flow tag ID according to the rate limiting parameter (Vd, Ld) for traffic monitoring: - when the monitored service data traffic does not violate the agreed low threshold parameter (Vdmin, Ldmin), the data packet is marked as green; When the monitored service data traffic exceeds the agreed low threshold parameter (Vdmin, Ldmin) but does not exceed the agreed high threshold parameter (Vdmax, Ldmax), the packet is marked yellow;

11 180600164 When the service data traffic exceeds the agreed high threshold parameter (Vdmax, Ldmax), the data packet is marked in red or the data packet can be directly discarded.

 The color tag of the packet is passed to the queue management/scheduling module.

C. When the queue management/scheduling module receives the data packet, it determines whether the newly received data packet is queued according to the capacity of the to-be-scheduled data packet in the target queue under the VCG port and the color and length of the newly received data packet.

 Cl, discards received packets marked in red.

 C2. The received packet marked as yellow/green performs the following processing according to the queue status: When all the packet capacity in the queue is less than the queue low threshold Lh, the data packet enters the queue; all the packet capacity in the queue is greater than the queue low threshold Lh but When the queue high threshold Lf is less than the queue high threshold, packets marked in green are queued, and packets marked in yellow are discarded.

 When all packet sizes in the queue are greater than the queue high threshold Lf, all newly received packets are discarded.

D. The queue management/scheduling module performs scheduling processing according to the port bandwidth, and sends the data packet in the queue under the port to the output port, and sends the data packet out of the device. The output port includes the VCG port and the Ethernet port. The data sent by the VCG port is sent to the device through the SDH interface after performing GFP encapsulation in the EOS module.

In this embodiment, the bandwidth is non-destructively controlled by two-stage traffic monitoring:

 The first level: The monitoring and processing of the triggered flow control only affects the processing of the PAUSE frame; 'Second level: The rate limit monitoring and processing can only be lost.

 This is because the monitoring bandwidth that triggers the flow control is smaller than the rate-limited monitoring bandwidth to ensure that the service is not lost: When the remote end receives the PAUSE frame without lowering the packet sending rate, the second-level rate limiting mechanism detects that the service is invalid, and performs discarding processing. It is possible to lose the package.

 The embodiments illustrated in Figures 2 and 3 above illustrate a general rate-based implementation flow.

12 180600164 The method of quantity control. Figure 4 shows an extended application of flow control. The following is a description of a flow control method for the VCG output port of the LCAS protocol that supports the LCAS protocol when the bandwidth changes. For the process flow, see the flowchart in Figure 4.

 4.1 When the EOS process supports the LCAS protocol, the VCG bandwidth changes due to the failure of some VC channels, resulting in the dynamic addition and deletion of the number of VCG members. When the bandwidth of the VCG is smaller than the rate threshold Vc in the Policing parameter of the traffic control, the rate limiting Policing parameters (Vd, Ld) cannot effectively control the sending data rate, and the queue of data on the output port will be lost due to scheduling blocking. Therefore, when the bandwidth that the VCG can provide is less than Vc, the management control module modifies the Policing parameter used by the Policing module downstream label ID according to the actual bandwidth of the VCG: Modify Vc to be less than or equal to the actual bandwidth of the VCG, and Lc remains unchanged.

 4.2 The flow control processing flow of the Policing module is the same as the normal processing flow: The traffic of the input service data of the flow label ID is monitored. When the service data traffic violates the new flow control policy parameter (Vc, Lc), the flow control frame processing process is triggered. The rate control Policing parameter processing is consistent with the general processing flow processing.

 According to the VCG bandwidth, the Policing parameter of the flow control is dynamically adjusted. When the VCG bandwidth is smaller than the default configuration, the packet loss probability of the service data is effectively reduced, and the service loss on the transmission path is avoided.

 In the embodiment shown in FIG. 2, FIG. 3, and FIG. 4, the management control module can report the bandwidth change of the service through the software interface, and can provide real-time bandwidth information of the access service, and the service management function on the MSTP device is more perfect. INDUSTRIAL APPLICABILITY The present invention discloses an apparatus and method for implementing flow control based on rate limiting on an MSTP device, which is used for implementing rate-based flow control on a multi-service transmission platform transmission device in a communication system to ensure packet-based services. The data stream is transmitted in the network without damage, and provides service bandwidth detection and reporting. Through the bandwidth and flow control mechanism, the resource occupation of the abnormal service is reduced, the service is prevented from being damaged, and the network transmission quality is improved.

13 180600164

Claims

 Claims

 A device for implementing flow control based on rate limiting on a multi-service transmission platform device, comprising: a data input module, a flow classification module, a Policing module, a queue management/scheduling module, and a data output module, which are sequentially connected in sequence; And a management control module for controlling and connecting to the above module, wherein

 a data input module, configured to receive an input data stream;

 The traffic classification module allocates a flow label for the input data stream according to the flow classification rule and determines a corresponding output queue, and simultaneously transmits the flow label to the management control module, and sends the data stream carrying the label to the Policing module;

 The management control module sets the Policing control parameters according to the agreed rules, including a speed limit threshold for rate control and a flow control threshold for flow control;

 The Policing module performs traffic monitoring on the received data according to the flow label transmitted by the flow classification module and the protocol policy parameter of the flow label transmitted by the management control module, and when the input data traffic is greater than the flow control threshold, the remote device The node sends a flow control frame indicating that the input data traffic is reduced; when the output data traffic is greater than the speed limit threshold, discarding the corresponding data packet or marking the data packet as a violation data, and outputting the data stream to the queue management/scheduling module;

 The queue management/scheduling module manages and schedules the admitted data, discards the data packet marked as the violation data, performs the queue processing of the data packet marked as normal data, and sends the data packet to the corresponding output port for processing;

 The data output module is configured to output the normal data stream according to the processing result of the queue management/scheduling module.

 The device according to claim 1, wherein the device further comprises: a data encapsulation and an EOS processing module, connected to the queue management/scheduling module, for performing status detection of the SDH channel, When the number of members of the cascading VCG changes, the real-time bandwidth information of the SDH channel of the VCG is reported to the management control module.

 a flow control frame triggering module is connected to the Policing module, and triggers a corresponding flow control frame according to a monitoring result of a specific traffic flow label by the Policing module;

 The MAC control module completes the transmission and reception control of the data packet on the Ethernet interface.

14 180600164 The device according to claim 1, wherein the policy control parameter set by the management control module includes:

 The rate limit threshold for rate control, including the data rate Vd of the trigger rate control and the burst length Ld of the packet when configured as a single leaky bucket parameter, Vdmax/Ldmax and Vdmin/ when configured as a double leaky bucket parameter Ldmin;

 The flow control threshold for flow control includes a data rate Vc for triggering flow control and a packet burst length Lc when configured as a single leaky bucket parameter;

 Wherein, the burst length of all the data packets should satisfy one condition: greater than the maximum packet length allowed by the data stream.

 The device according to claim 3, wherein, in the policy module, when the input data traffic is less than or equal to the flow control threshold, stopping sending the flow indicating that the input data traffic is reduced to the remote device node is stopped. Control frame

 When the remote device does not respond to the flow control frame, it performs traffic monitoring on the output data. When the rate limit threshold is configured as a single leaky bucket parameter (Vd, Ld), if the output data flow rate is greater than the speed limit threshold value Vd, Then discard the corresponding data packet or mark the data packet as red to indicate the violation data, no shell ' J , mark the data packet as green to indicate normal data, and output the data stream to the queue management/scheduling module; the speed limit threshold value is configured as double When the bucket parameters Vdmax/Ldmax and Vdmin/Ldmin are leaked, when the monitored traffic data traffic does not violate the agreed low threshold parameter (Vdmin, Ldmin), the packet is marked as green;

 When the monitored traffic data traffic exceeds the agreed low threshold parameter (Vdmin, Ldmin) but does not exceed the agreed high threshold parameter (Vdmax, Ldma), the packet is marked yellow;

 When the service data traffic exceeds the agreed high threshold parameter (Vdmax, Ldmax), the data packet is marked in red or the data packet can be directly discarded.

 The color tag of the packet is passed to the queue management/scheduling module.

 5. The apparatus according to claim 4, wherein in the queue management/scheduling module: the discarding control parameters of the queue comprise two types: a low threshold Lh of half full and a high threshold Lf of fast full; When receiving a packet for processing, the received packet marked in red is directly discarded.

15 180600164 Receive packets marked as yellow/green perform the following processing depending on the queue status: .

 When all packet sizes in the queue are less than the queue low threshold Lh, the packets enter the queue. When all packet sizes in the queue are greater than the queue low threshold Lli but less than the queue high threshold Lf, the packets marked in green are queued, marked yellow. Packets are discarded;

 When all packet sizes in the queue are greater than the queue high threshold Lf, all newly received packets are discarded. '

 The device of claim 2, wherein the data encapsulation and the EOS processing module are reported to the management control module when the bandwidth of the virtual concatenation group VCG is smaller than the flow control threshold, and the management control module is based on the virtual The actual bandwidth of the cascading group VCG is modified to be equal to or equal to the actual bandwidth of the virtual concatenation group VCG.

 7. A method for implementing flow control based on the apparatus of claim 1, comprising the steps of:

 (1) The flow classification module allocates a corresponding flow label to the input data stream according to the flow classification rule, determines an output queue of the input data packet, and reports the flow label to the management control module;

 (2) The Policing control parameter is set by the management control module for the service corresponding to the flow label according to the agreed rule, including a flow control threshold for flow control, and a speed limit threshold for the rate limit;

 (3) The Policing module performs traffic monitoring on the service data carrying the flow label according to the policy control parameter negotiated by the management control module. When the input data traffic is greater than the flow control threshold, traffic control is started, and the remote device node is sent to the remote device node for sending a flow control frame indicating a decrease in input data traffic;

 (4) When the remote device does not respond to the flow control frame, the policy module monitors the service data carrying the flow label according to the policy control parameter negotiated by the management control module. When the output data rate is greater than the speed limit threshold, the label is marked. The data packet is the violation data; otherwise, it is marked as normal data, and the marked data packet is forwarded to the queue management/scheduling module;

 (5) The queue management/scheduling module manages and schedules the accepted data, discards the data packet marked as the violation data according to the tag information of the received data packet, and performs the queue processing of the data packet marked as normal data. , dispatched to the corresponding output port.

 8. The method according to claim 7, wherein the step (2) is configured with Policing

16 180600164 The steps to control the parameters are:

 The rate limit threshold for rate control is configured, and when configured as a single leaky bucket parameter, the data rate Vd and the burst length Ld of the trigger rate control are included, which is Vdmax/Ldmax when configured as a double leaky bucket parameter. And Vdmin/Ldmin;

 Configure a flow control threshold for flow control, which includes a data rate Vc for triggering flow control and a packet burst length Lc when configured as a single leaky bucket parameter;

 Wherein, the burst length of all the data packets should satisfy one condition: 'greater than the maximum packet length allowed by the data stream.

 The method according to claim 8, wherein the step (3) is further divided into: a flow label transmitted by the flow classification module and a protocol policy parameter of the flow label transmitted by the management control module, Input data stream for traffic monitoring:

 When the input data traffic is greater than the flow control threshold value Vc, sending a flow control frame indicating that the input data traffic is reduced to the remote device node;

 When the input data traffic returns to less than or equal to the flow control threshold value Vc, the flow control frame indicating that the input data traffic is reduced is stopped from being sent to the remote device node. .

 The method according to claim 8 or 9, wherein the step (4) is further divided into:

 Traffic monitoring is performed on the output data according to the flow label delivered by the flow classification module and the protocol Policing parameter of the flow label transmitted by the management control module:

 When the speed limit threshold is configured as a single leaky bucket parameter (Vd, Ld), if the output data traffic is greater than the speed limit threshold Vd, the corresponding data packet is discarded or the data packet is marked red to indicate the violation data. J, mark the data packet as green for normal data, and output data flow to the queue management/scheduling module; when the speed limit threshold is configured as double leaky bucket parameters Vdmax/Ldmax and Vdmin/Ldmin, if the monitored service data traffic does not violate The protocol low threshold parameter (Vdmin, Ldmin) marks the packet as green; if the monitored service data traffic exceeds the agreed low threshold parameter (Vdmin, Ldmin) but does not exceed the agreed high threshold parameter (Vdmax, Ldmax), the packet Marked as yellow.

17 180600164 If the service data traffic exceeds the agreed high threshold parameter (Vdmax, Ldmax), the data packet is marked in red or the data packet can be directly discarded.

 Pass the color tag of the packet to the queue management/scheduling module.

 The method of claim 10, wherein the step ('2) further comprises the step of configuring a drop control parameter of the queue, wherein the configured queue drop control parameter comprises: a half full low threshold Lh and a fast full High threshold Lf;

 Correspondingly, in the step (5), the queue management/scheduling module discards the received data packet marked in red when processing the received data packet, and performs the following processing according to the queue status of the received data packet marked in yellow/green. :

 When all packet sizes in the queue are less than the queue low threshold Lh, the packets enter the queue. When all packet sizes in the queue are greater than the queue low threshold Lh but less than the queue high threshold Lf, the packets marked in green are queued, marked yellow. Packets are discarded;

 When all packet sizes in the queue are greater than the queue high threshold Lf, all newly received packets are discarded.

 12. The method of claim 1 wherein the method further comprises the steps of:

 If the data encapsulation and the EOS processing module are used as the output, if the bandwidth of the virtual concatenation group VCG is smaller than the flow control threshold, the management control module is reported, and the management control module modifies the policy module according to the actual bandwidth of the virtual concatenation group VCG. The flow control threshold is such that it is less than or equal to the actual bandwidth of the virtual concatenation group VCG.

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