WO2007036109A1

WO2007036109A1 - A method for selecting the loop in the resilient packet ring and the system thereof

Info

Publication number: WO2007036109A1
Application number: PCT/CN2006/001544
Authority: WO
Inventors: You Gao; Peng Lv
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2005-09-28
Filing date: 2006-07-03
Publication date: 2007-04-05
Also published as: CN1859280A

Abstract

A method for selecting the loop in the resilient packet ring primarily includes: a) determine the node hop number and the network state of each optional loop between the source node and the host node for transmitting and receiving the data in the resilient packet ring; b) select and determine the loop to transmit and receive data from the optional loops based on the node hop number and the network state of each optional loop between the source node and the host node. Because the network state of the loop is considered enough while selecting the loop in the invention, thereby the loop selecting is more reasonable, the waste of the effective bandwidth in the RPR ring network is reduced and the problems produced by the imbalance between the network states in the different ringlet directions are reduced.

Description

Method and system for ring selection in elastic packet ring

Field of the Invention This invention relates to resilient packet ring techniques and, more particularly, to a method and system for ring selection in an elastic packet ring.

Background technique

RPR (Resilient Packet Ring) Resilient Packet Ring technology provides a good group for broadband IP metropolitan area network operators because of the intelligence of IP, the economics of Ethernet and the high bandwidth efficiency and reliability of fiber-optic ring networks. Network solution. RPR technology makes it possible for operators to provide carrier-grade services at a low cost within the metropolitan area network, providing network reliability similar to SDH (Synchronous Optical Transport Sequence) and reducing transmission costs. RPR is different from traditional MAC (Media Access Control). The most attractive feature is carrier-class reliability, which not only limits the processing of data-oriented services, but also forms a comprehensive transmission for processing multi-service transmission. solution.

Referring to Figure 1, similar to the SDH topology, RPR is a reciprocal dual-ring topology, and each optical path on the ring operates at the same rate. The difference is that both rings of RPR can transmit data, and the two rings are called RingletO and Ringletl respectively. The data transmission direction of the RPR 0 ring is clockwise, and the data transmission direction of the 1 ring is counterclockwise. Each RPR node uses the 48-bit MAC address used in the Ethernet as the address identifier. Therefore, from the link layer of the RPR node device, the physical optical interfaces of the two rings of the 0 ring and the 1 ring are only received. A link layer interface.

Referring to Figure 2, an RPR node has one MAC entity and two physical layer entities. The MAC entity contains a MAC control entity and two MAC data path entities, and is called an access point. The physical layer entity is divided into an east physical layer and a west physical layer according to the loop direction. The "sending port" of the eastward physical layer and the "receiving port" of the westward physical layer are connected by the outer ring data path to form the 0 ring of the RPR; likewise, the "receiving port" of the east physical layer and the westward physical layer" The transmit port "connects through the inner loop data path to form a ring of RPR.

Different RPR nodes, when connected to an RPR ring, must use the eastbound interface of the node to connect to the westbound interface of the next node; and use the westbound interface of the node to connect to the eastbound interface of the previous node. All RPR nodes are connected end to end to form a complete RPR ring.

Referring to Figure 3, there are two ways to send data between nodes, namely 0 ring and 1 ring, and The mechanism for ring selection according to the IEEE 802.17 node is determined only by the number of hops between nodes, that is, Router 1 to Router 3 - the 0 ring is selected, and Router 1 to Router 5 must only select 1 ring.

The ring selection of the above RPR nodes only depends on the number of hops between the nodes, that is, when the number of hops that are different from the specified node is different, the direction of the hops is selected. This causes a problem: If the selected hop count is small but very congested, and the other loop hop count is large, but the link is idle, then there is no complete ring selection mechanism to ensure full utilization of the ring. The bandwidth advantage of the network may even lead to packet loss. As shown in Figure 3, the traffic from Router 1 to Router 3 is 0. After the hop count ring selection mechanism selects the 0 ring, the traffic is likely to be lost. If the traffic is 1 ring. If you don't go through any congested domains, the chances of losing packets are much smaller. It can be seen that the above prior art is defective in implementing ring selection, and the probability of losing packets is much smaller. It can be seen that the above prior art is defective in implementing ring selection, and the more the ring with uneven flow on each node, the more obvious the defects of the prior art described above.

Summary of the invention

The technical problem to be solved by the present invention is to avoid the prior art that only relying on the number of hops between nodes to perform ring selection, the ring selection mechanism is incomplete, and the bandwidth advantage of the existing ring network cannot be fully utilized, and the defect of packet loss may be caused.

In order to solve the above problem, the method for selecting a ring of an elastic packet ring includes: a. determining a node hop count and a network state of each optional loop between source and sink nodes for performing data transmission and reception in an elastic packet ring;

b. Select, according to the number of node hops of the optional loop between the source and sink nodes and the network state, select a loop for transmitting and receiving data from the optional loop.

Optionally, step b includes: determining each of the optional loop node hop weight level values and the network state weight level value; selecting a loop with the highest sum of the node hop weight level value and the network state weight level value as the data for transmitting and receiving data Loop.

The network state weight level value of the loop includes at least a congestion state weight level value, a link state weight level value, a traffic state weight level value, and a node level state weight level value. The network state weight level value may be ranked as follows:

Congestion state weight class value, link state weight class value, traffic state weight class value, and node level state weight class value.

Optionally, step b includes:

Determine the loop with the smallest number of nodes hops;

Detecting whether the state of the loop network with the smallest hop count of the node meets the requirement. If yes, select the loop with the smallest hop count for data transmission; otherwise, select another loop with better network state for data transmission.

The network status includes a congestion status, a link status, a traffic status, and a node level status.

Detecting whether the loop network status meets the requirements includes the following steps:

Determining a sum of a network state weight grading value corresponding to a congestion state weight grading value, a link state weight grading value, a traffic state weight grading value, and a node grading grading value;

Determining whether the sum of the network state weight grading values on the loop with the smallest hop count of the node reaches a predetermined threshold, and if so, determining that the network state on the loop with the smallest hop count reaches the requirement, otherwise, determining that the hop count of the node is the smallest The network status on the loop did not meet the requirements.

In order to solve the above problems, the present invention further provides a system for ring selection in an elastic packet ring, comprising: a physical layer, including a plurality of nodes constituting an elastic packet ring; and a network layer, which is based on a source for data transmission and reception in the elastic packet ring Select the number of node hops and network status of each optional loop between the sink nodes, and select the loop for sending and receiving data.

Compared with the prior art, the present invention has the following beneficial effects:

When selecting a ring, the present invention first determines the number of node hops of each optional loop between the source and sink nodes in the resilient packet ring and the network state; and then according to the number of node hops of the optional loop between the source and sink nodes and The network status selects a loop from the optional loop that determines the data to be sent and received. Since the network state of the loop is fully considered in the ring selection, the ring selection is more reasonable, the waste of effective bandwidth on the RPR ring network is reduced, and the problem caused by the imbalance of network states in different loop directions is reduced.

DRAWINGS

1 is a schematic diagram of a prior art RPR reciprocal double loop topology; 2 is a schematic diagram of a connection of a prior art RPR node;

3 is a schematic diagram of performing ring selection on a conventional RPR;

4 is a flow chart of performing ring selection on an RPR according to a first embodiment of the present invention;

Figure 5 is a flow chart showing ring selection on an RPR in accordance with a second embodiment of the present invention.

detailed description

The core of the present invention is to optimize the existing RPR ring selection mechanism and increase the ring selection decision point. When selecting a ring, not only the number of node hops of the optional loop between the source and sink nodes but also the optional ring between the source and sink nodes is considered. The network status of the road can fully utilize the bandwidth of the entire network, reduce the problems caused by the imbalance of network conditions in different loop directions, and increase the completeness and reliability of the ring selection mechanism. The following describes the specific embodiments.

The system for selecting a ring in an elastic packet ring includes at least a physical layer and a network layer, where the physical layer includes a plurality of nodes constituting an elastic packet ring, and the network layer can respectively perform data transmission and reception between the source and sink nodes according to the elastic packet ring. Select the number of node hops of the loop and the network status, and select the loop for sending and receiving data. It should be understood that the system for selecting a ring in the elastic packet ring provided by the present invention has the same structure as the existing system, except that the conditions of the network layer ring selection are changed.

Referring to Figure 4, there is shown a flow chart for ring selection on an RPR in accordance with a first embodiment of the present invention. In this embodiment, the number of hops of the optional loop parameter node between the source and sink nodes and the network state are set. For example, in the specific implementation, the network state decision is made according to the following network state decision point - the congestion domain decision point

If the current selected ring direction (for example, ring 0) is detected to have a congestion domain, and the other ring direction (for example, ring 1) detects no congestion, the ring selection mechanism should switch the traffic that passes through the congestion domain to the non-congested domain. The ring is up. For example, as shown in Figure 3, the default ring selection mechanism of the flow from Router 1 to Router 3 is determined by the number of hops to go through the 0 ring. However, since the 0 ring will pass through the congestion domain eight, the detection mechanism detects this. Select 1 ring without selecting 0 ring. This avoids the possibility of packet loss due to congestion.

Link state decision point

If there is no congestion domain, if the link states of the 0 ring and the 1 ring that reach the same node are very different, select a good link with a good link state. Link status includes transmission delay, bit error rate, link level, and so on. The link level is a letter indicating a link between the previous node and the local node. A value of the degree.

Traffic statistics decision point

In the case where there is no congestion domain and there is no significant difference in the link state of the two loops, if the traffic of the two loops is very different, the loop with a small traffic flow can be selected at an appropriate timing. For example, a node has a flow rate of 9.5G in the 1st ring and only 0.7G in the 0 ring, and the traffic can be selected to the 0 ring at an appropriate timing.

Node level decision point

Increase the concept of node level (1 to 255). The higher the node level, the higher the credit rating of the node. In the ring selection, if the above judgment points cannot accurately determine the ring selection situation, and the different ring points pass through the nodes, the node levels are very different (for example, if there are many nodes in the 0 ring, Clas _S = 255, such as walking 1 ring has Many nodes have Clas _S = l, then 0 ring can be selected according to the level), so that the node level can be used as a judgment point of the ring selection to perform ring selection.

Based on the above decision points, the present invention may add corresponding network state weight level values as follows: a congestion state weight class value, a link state weight class value, a traffic state weight class value, and a node level state weight class value, each of the above network state weights The value is different. Generally speaking, the congestion domain decision point has the highest weight value, and then the link state weight level value, the traffic statistics weight level value, and the node level weight level value. In the ring selection decision, the sum of the weights determined by each decision point is used as the criterion for selecting the ring.

In the step of performing ring selection, in step 11, in step 11, first, each optional loop node hop weight level value and a network state weight level value are determined, and the network state weight level value of the loop includes at least a congestion state weight level value. One of the link state weight level value, the traffic state weight level value, and the node level state weight level value; that is, the network state weight level value of the loop may include only one of the weights according to the actual needs of the user. A gradation value (such as a link state weight grading value), or includes several or all of the weight grading values.

Then, in step 12, the loop with the highest sum of the node hop weight level value and the network state weight level value is selected as the loop for transmitting and receiving data, so that after fully considering the network state of the loop, the selected loop is more consistent. The actual data transmission needs.

Referring to Figure 5, a flow chart of a second embodiment of ring selection on the RPR of the present invention.

In this embodiment, when selecting a ring, first consider the number of node hops, and the loop network with the smallest hop count in the selected node. If the network status does not meet the requirements, select another loop with better network status to transmit data. The specific process is as follows:

Step 21: Determine a loop with the smallest number of hops of the node;

Step 22: Detect whether the state of the loop network with the smallest hop count of the node meets the requirement. Referring to the foregoing description, the network state in the present invention may include a congestion state, a link state, a traffic state, and a node level state, and specifically detect a loop network state. Whether or not the requirements are met is mainly achieved by the following methods:

Step 23: If the network state of the loop with the smallest hop count reaches the requirement, select the loop with the smallest hop count for data transmission;

Step 24: If the network state of the loop with the smallest hop count reaches the requirement, another loop with a better network state is selected for data transmission.

The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It is considered as the scope of protection of the present invention.

Claims

Claim

A method for selecting a ring in an elastic packet ring, comprising:

a. determining a node hop count and a network state of each optional loop between the source and sink nodes for transmitting and receiving data in the resilient packet ring;

The method of selecting a ring in an elastic packet ring according to claim 1, wherein the step b comprises:

Determining the value of each optional loop node hop weight level and the network status weight level value; selecting the loop with the highest sum of the node hop weight level value and the network state weight level value as the loop for transmitting and receiving data.

The method for selecting a ring in an elastic packet ring according to claim 2, wherein the network state weight level value of the loop includes at least a congestion state weight level value, a link state weight level value, and a traffic state weight level. One of the value and the node level status weight level value.

The method for selecting a ring in an elastic packet ring according to claim 3, wherein the network state weight level values are arranged from high to low as follows:

Determine the loop with the smallest number of nodes hops;

The method for selecting a ring in an elastic packet ring according to claim 5, wherein the network state includes a congestion state, a link state, a traffic state, and a node level state;

Determining the minimum number of hops of the node corresponds to the congestion state weight level value and the link state weight level The sum of the value of each value of the network state weight class of the value, the traffic state weight class value, and the node class state weight class value;

7. A system for ring selection in an elastic packet ring, characterized in that:

a physical layer, including a plurality of nodes constituting an elastic packet ring;

The network layer selects a loop for transmitting and receiving data according to the number of node hops of each optional loop between the source and sink nodes for transmitting and receiving data in the resilient packet ring and the network state.

8. The system for ring selection in an elastic packet ring according to claim 7, wherein

The network layer selects the loop with the highest sum of the node hop weight level value and the network state weight level value as a loop for transmitting and receiving data.

9. The system for ring selection in an elastic packet ring according to claim 7, wherein

If the loop network state with the smallest number of node hops reaches the required level, the network layer selects the loop with the smallest hop count of the node for data transmission; otherwise, selects another loop with better network state for data transmission.