JPS60177759A - Route selecting system of packet switching network - Google Patents

Abstract

PURPOSE:To reduce a packet transfer time, and to improve an efficiency of a trunk line by dividing each packet flowing into a packet switching network, into groups, with regard to a transmitting packet exchange, and adding group discriminating information to each packet so that each repeating packet exchange can select a transfer route based on the added group discriminating information. CONSTITUTION:In a packet transferred from a switchboard, not only addressed station information (dn) and transmitting station information (on) but also traffic group discriminating information (tg) are added to a transmitting packet (pkt) of a terminal. When a terminal equipment T1 transmits a packet destined for a terminal equipment T3 contained in a packet switchboard D, to a packet exchange, a traffic group discriminating part TS provided in a central control equipment CC discriminates a fact that the transmitting terminal equipment T1 belongs to the first track group, and informs its fact to a route selecting part SEL'. The route selecting part SEL' refers to addressed station information (dn)=D corresponding part decided from the received packet, checks a congested state of trunk lines L1, L2, and if the trunk line L1 is in the congested state, the trunk line L2 being the second priority route is selected as a packet transfer route.

Description

DETAILED DESCRIPTION OF THE INVENTION tal Technical Field of the Invention The present invention relates to a packet-switched network, and more particularly to a route selection method in a packet-switched network that can prevent traffic concentration within the packet-switched network.

([)) Technical background FIG. 1 is a diagram showing an example of a packet switching network to which the present invention is applied. In FIG. 1, the packet switching network is comprised of a plurality of packet switches A to E. Each of the packet exchanges A to E has a plurality of packet transfer routes corresponding to each destination station. For example, bucket exchanger A
When the destination station is a packet switch, there are two types of packet transfer routes: a relay route L1 leading to bucket switch B and a relay route L2 leading to bucket switch C. By selecting the following, the communication status, reliability, and economic efficiency within the packet switching network are improved.

(C1 Prior Art and Problems FIG. 2 is a diagram showing an example of a conventional route selection method (hereinafter referred to as a routing method) in this type of bucket exchanger. In FIG. 2, the bucket exchanger A in FIG. For example, the switch A to the bucket machine 1 is the terminal device T1.
and T2 and the relay paths L1 and L2, a communication device CMU that transmits and receives Paqueso 1-, a central control device CC that controls packet transfer, a bucket buffer that temporarily stores transferred buckets, and a central control device C.
A main memory device MM is provided for storing various information necessary when C controls bucket transfer.

A routing table TBL is provided in the main storage device MM, and each destination station (
Route identification information rn (Ll...) indicating the bucket transfer route corresponding to B-C, D, E) is stored. For example, the route identification information rn for the destination station information dn=D indicates that the relay route I, 1 is selected as the first priority route, and the relay route L2 is selected as the second priority route. Now, when the terminal device T1 transmits a bucket destined for the terminal device T3 accommodated in the bucket exchanger to the bucket exchanger, the route selection unit SEL provided in the central controller CC selects the destination station from the received bucket to the bucket exchanger. destination station information d in the routing table TBL in the main memory MM.
Referring to n=D corresponding part, relay route L which is the first priority route
1 convergence shape! ? 3 (for example, the queue length of buckets waiting to be sent), and if the congestion state has not been reached, the relay path L1 is selected as the bucket transfer path. If the relay route L1 is in a congested state, the route selection unit SEL checks the congested state of the relay route L2, which is the second priority route, and if the congestion state has not been reached, the route selection unit SEL selects the relay route L2 as the bucket transfer route. select. Next, when terminal device T2 transmits a bucket destined for terminal device T3, bucket switch A selects relay path L1 as the first priority route in the same process as described above, and even if relay path L1 is in a congested state, For example, the relay route L2 is selected as the second priority route. The same applies to packet switches B to E.

As is clear from the above explanation, in a conventional routing method, the selection order of bucket transfer routes for all buckets having the same destination station information dn is the same, so a specific packet switch in the bucket switching network, a specific Even when traffic is concentrated on a relay route, it is fixedly routed to the other station, which has the disadvantage of increasing the bucket transfer time and causing an imbalance in the efficiency of the relay route.

(dl Purpose of the Invention The purpose of the present invention is to eliminate the drawbacks of the conventional routing method as described above, to prevent as much as possible the concentration of traffic on a specific bucket switch and a specific relay route in a bucket switching network, and to reduce packet transfer time. The present invention also provides a route selection method that makes it possible to improve the efficiency of relay routes.

+ [41 Configuration of the Invention The object is to have a plurality of bucket transfer routes between an originating bucket exchanger and an incoming bucket exchanger, and to select one route from the plurality of bucket transfer routes to transfer the bucket. In a packet switching network, the originating bucket switch groups each bucket that flows into the bucket switching network and adds group identification information to each bucket, and each intermediate bucket switch adds the group identification information to each bucket that it receives. This is achieved by selecting a transfer route based on group identification information.

Accordingly, in the present invention, the traffic transferred by the packet switching network is divided into a plurality of traffic groups, and each relay bucket switch selects a different bucket transfer route corresponding to each traffic group. The load within the network will be distributed.

(f) Examples of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram illustrating a forwarding bucket according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a traffic group routing scheme according to an embodiment of the present invention. Note that the same reference numerals indicate the same objects throughout the figures. Further, the target packet switching network will be explained using the one shown in FIG. 1 as an example. In FIG. 3, in addition to the destination station information dn and the originating station information on, traffic group identification information tg is added to the packet transferred from the exchange to the transmission packet 1-pkt of the terminal. In addition, in FIG. 4 illustrating the flow to the packet switch from FIG. Two types of routing tables TBL1 and TBL2 are set up? I'm getting fucked. The bucket exchange mA classifies the terminal devices accommodated into a first traffic group and a second traffic group. For example, the terminal device T1 belongs to the first traffic group, and the terminal device T2 belongs to the second traffic group. Routing table T B
L1 is used to select a route corresponding to the first traffic group, and routing table TBL2 is used to select a route corresponding to the second traffic group, and the same destination station information dn
Route identification information rn can be set independently for each.

For example, route classification information 91rn for destination station information dn=D
, the routing table TBLI stores the relay route L1 as the first priority route and the relay route L2 as the second priority route, and the routing table TBL2 stores the relay route L2 as the first priority route and the relay route L1 as the second priority route. It is stored. Now, when the terminal device T1 transmits a packet destined for the terminal device T3 accommodated in the packet switch laA to the packet exchange laA, the one-hitter group identification unit TS provided in the central control unit CC recognizes that the transmitting terminal device T I It is identified as belonging to the first torahinoku group, and the route selection unit SEL' is notified of this fact. As a result, the route selection section SEL" selects the routing table TBLI provided in the main storage device MM corresponding to the first traffic group, and refers to the destination station information dn=D corresponding section determined from the received packet. , examines the congestion state of relay route L1, which is the first priority route, and selects relay route L1 as the packet transfer route if the congestion state has not been reached.If relay route L1 is in a light congestion state, route L1 is selected as the packet transfer route. The selection unit SEL" checks the congestion state of the relay path L2, which is the second priority route, and if the congestion state has not been reached, the selection unit SEL" selects the relay path L2, which is the second priority route.
is selected as the bucket transfer route. Note that the central control unit CC transmits the terminal's transmission information received from the terminal device TI)
p k t, destination station information dn=D, originating station information on=f
i, traffic group identification information tg (for example, logical value O) indicating that the packet is related to the first traffic group.
) is added and sent to the selected relay path L1 or L2. Next, when the terminal device T2 transmits a packet destined for the terminal device T3 to the packet switch, the traffic group identification unit TS in the central controller CC identifies that the sending terminal device T2 belongs to the second traffic group, and performs route selection. Department SEL' will be notified accordingly.

As a result, the route selection section SEL" selects the routing table TBL2 corresponding to the second traffic group, refers to the destination station information dn=D corresponding section determined from the received packet, and selects the first priority route, the relay route L2. Check the congestion status,
If the comparison state has not been reached, the relay path L2 is selected as the bucket transfer path. If the relay route L2 is in a congestion state, the route selection unit SEL' checks the width comparison state of the relay route L1, which is the second priority route, and if the congestion condition has not been reached, the route selection unit SEL' selects the relay routes 1 and 2. Select as the bucket transfer route.

Note that the central control device CC sends destination station information dn-I to the terminal transmission bucket L-pkL received from the terminal device T2.
), in addition to the originating station information on=A, traffic group identification information t indicating that the packet is related to the second traffic group.
g (for example, logical value 1) and sends it to the selected relay path L2 or Ll. In the packet switch B, the main storage device MM is also provided with a routing table TBL1 corresponding to the first traffic group and a routing table TBL2 corresponding to the second traffic group. station information dn
- Route classification information 9[1rn] is stored with relay route L3 as the first priority route and relay route L4 as the second priority route, and route identification information for destination station information φn=D is stored in the routing table TBL2. As rn, the relay route L4 is stored as the first priority route, and the relay route L3 is stored as the second priority route. When the packet transferred from packet switch A arrives from live route L1, bucket switch B
The traffic group identification unit TS provided in the central control unit CC identifies the 1-rahisoku group identification information tg included in the transfer packet, determines which of the first and second traffic groups it relates to, and determines the route. The selection unit SEL is notified of the determination result. When the route selection unit SEL is notified of the first traffic group relationship, the route selection unit SEL selects the routing table TBL.
Refer to the destination station information 911dn=D corresponding section of I, and set the relay route L3 as the first priority route and the relay route L as the second priority route.
Select 4.

In addition, if the second traffic group relationship is not notified, the route selection unit SEL' refers to the destination station information dn=D corresponding section of the routing table TBL2, and selects the relay route L4 as the first priority route and the second priority route. The relay route L4 is selected as the relay route L4. The same applies to packet switches C and E.

That is, the route identification information rn stored in each destination station information dn=D corresponding section of the routing tables TBLI and TBL2 in the packet exchanges A, B, C, and E is as follows.
Each is shown in the table below.

As is clear from the above description, according to this embodiment, packets destined for the same packet switch select relay routes in different selection orders depending on the traffic group to which the transmitting terminal device belongs. Traffic will no longer be concentrated on the network, and the load on the packet switching network will be distributed. Furthermore, if high-speed transmission paths are used for the relay paths L1 and L3, which are preferentially selected for the first traffic group, the transfer efficiency of the first traffic group-related buckets will be improved, and, for example, the transfer efficiency of the first traffic group-related buckets will be improved. Consideration will be given to operations that will yield greater effects, such as making it belong to the first traffic group.

Note that FIGS. 3 and 4 are only one embodiment of the present invention; for example, the traffic group is not limited to two verticals, first and second, and the present invention also applies when there are two or more vertical groups. The effect of the invention remains the same. (In this case, it is sufficient to have multiple bits of route identification information as data.) Also, the routing method for the same traffic group is not limited to the fixed detour method illustrated, and many other variations can be considered, but any Even in this case, the effects of the present invention remain the same. Furthermore, it goes without saying that the configuration of the bucket switching network to which the present invention is applied is not limited to that shown in the drawings.

! gl Effects of the Invention - As described above, according to the present invention, in the bucket switching network, traffic to be transferred is divided into a plurality of traffic groups, and each relay packet switch is configured to provide a different packet transfer route corresponding to each traffic group. Since the selection is made, the concentration of traffic on a specific station and a specific relay route is prevented, and the packet transfer time can be reduced and the efficiency of the relay route can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a bucket switching network to which the present invention is applied, FIG. 2 is a diagram showing an example of a conventional routing system, and FIG. 3 is a diagram showing forwarded packets according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a traffic group routing scheme according to an embodiment of the present invention. In the figure, A to E are packet switches, CC is a central control unit, CMU is a communication device, dn is destination station information, Ll to Ll are relay paths, MM is main storage, On is source station information, and pkt is terminal information. Transmission packet, rn is route identification information,
SEL and 5EL1 are route selection units, T1 to T3 are terminal devices, TBL, TBLI and TBL2 are routing tables, tg is traffic group identification information, and TS is a traffic group identification unit. Kaya 1st number 2 Kuchie 3 Kuchi* 4 Kuchi

Claims (1)

[Claims] In a packet switching network that has a plurality of packet transfer routes between an originating packet switch and an incoming packet/node switch, and selects one route from among the plurality of packet transfer routes to transfer the packet, the outgoing packet The switching equipment groups each packet flowing into the packet switching network, adds group identification information to each packet, and each relay packet switching equipment forwards the packets based on the group identification information added to each of the received packets. A route selection method in a packet-switched network, characterized by using route selection means.