JP2580618B2 - Congestion alleviation method at the time of station congestion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a network management sensor coupled to each of a plurality of packet switching stations constituting one communication network by a network management information path from one packet switching station. A congestion mitigation method at the time of station congestion that received information.

[Conventional technology]

The conventional congestion mitigation method at the time of station congestion is a packet network, when a certain station becomes congested, the station does not accept a new call, and softens the congestion by limiting the amount of data received for existing calls. In addition, the network management sensor in the packet network executes the processing instruction in the station when receiving the notification of the congestion of the communication network, thereby reducing the congestion.

[Problems to be solved by the invention]

The conventional congestion mitigation method at the time of station congestion described above does not accept a new call at the congestion station and, for an existing call, restricts the data flowing into the congestion station mainly by limiting the amount of data received. Waiting for data in the congestion station to be swept out to release congestion. In addition, since the network management sensor only instructs the station to perform the above-described processing, there is a problem that the congestion is slowly alleviated, and there is a possibility that the congestion may occur again even if the congestion state is escaped.

SUMMARY OF THE INVENTION An object of the present invention is to provide a congestion mitigation method at the time of station congestion which solves the above problem by the network management sensor taking control of the call on the entire network by call path selection processing at the time of station congestion.

[Means for solving the problem]

The congestion mitigation method at the time of station congestion according to the present invention is characterized in that a network management sensor coupled to each of a plurality of packet switching stations constituting one communication network by a network management information path receives congestion information from one packet switching station. Line, logical channel,
A caller of a relay call that receives a call volume and information for identifying an adjacent calling station and a called station and selects a relay call that satisfies one or more predetermined conditions from the relay calls. A switching path is selected for a relay call selected on a transmission path connecting a station and a called station, and information on the selected switching path is notified to at least the calling station to notify the calling station and the called station. When the switching path to the station is set, the connection path at the congested station of the relay call that has been set is disconnected, and the switching path is switched to the switching path between the calling station and the called station.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart showing one embodiment of a main operation procedure of a network management center as a claim correspondence diagram of the present invention, and FIG. 2 is a functional block connection diagram showing one configuration example for executing the first.

Prior to the description of the operation procedure of FIG. 1, the functional block configuration and network configuration of each station when the station is congested will be described with reference to FIG. 2 and FIG.

In FIG. 2, the congestion station 10 includes a switch 11, a congestion detection unit 12, a relay call data memory 13, and a connection release unit 14.
To connect the transmission line 51 on the calling side and the transmission line 52 on the called side via the switch 11. The calling station 20 of the congested station 10 drives the switch 21, the link forming means 22, the transmission path setting means 23, and the connection path switching means 24. The called station 30 of the congested station 10 includes a switch 31, a link forming unit 32, and a connection path switching unit 33.
Drive. The network management center 40 is provided with a detour setting means 41.
And sends the detour information to each station to process the connection path switching.

The switch 11 is connected to each of the calling station 20 and the called station 30 via each of the transmission lines 51 and 52. The congestion detecting means 12 detects congestion at the station and notifies the network management center 40 of the congestion. The relay call data memory 13 stores traffic data for each call, for example, as shown in FIG. 4 (described later), and exchanges data with the network management center 40. The connection path releasing means 14 controls the switch 11 in accordance with an instruction from the network management sensor 40 to release the connection of the connected transmission path.

Each of the switches 21 and 31 accommodates and connects the transmission side of the calling station 20 and the called station 30 respectively. The link forming means 22 and 32 form a packet link in a packet switching network by obtaining call control information and performing a predetermined setting procedure. The transmission path setting procedure 23 controls the link forming means 22 in response to an instruction from the network management center 40 to form a predetermined packet link via the transmission path. The connection path switching means 24 and 33 control the switches 21 and 31 based on information from the network management center 40 to switch the connection of the transmission path. For example, as a detour after switching, the calling station 20 and the called station 30 are connected by a transmission line 61 that does not pass through the congested station 10.

The detour setting means 41 fetches the relay call data of the congested station 10, sets the detour, and notifies the transmission path setting means 23 of the calling station 20. One procedure of the detour setting will be described later with reference to FIG.

Next, the main operation procedure of the network management center will be described with reference to FIG. 1 and FIG. The procedure number code shown in FIG. 1 is entered in FIG. First, the network management center 40 having received the congestion occurrence information from the congestion station 10 from the congestion station 10 (procedure S1) requests the congestion station 10 to transmit relay call data (procedure S1).
2) and receive the relay call data (step S3). The network management center 40 selects a detour based on the received data (procedure
S4), and transmits the detour information to the calling side station 20 of the selected detour (procedure S5). The detour selection procedure in step S4 will be described in detail with reference to FIG. The calling station 20 newly forms a link with the called station 30 via the transmission line 61 based on the received detour information. The network management center 40 receives the information from the calling station 20 that the detour link has been formed (procedure
S6) When the congestion station 10 starts, the switching station is notified to the adjacent stations 20 and 30 on the calling side and the called side (step S7).
Then, the connection between the old transmission lines 51 and 52 of the call for which the detour is set is released, the calling station 20 changes the calling transmission path from the transmission path 51 to the transmission path 61, and the called station 30 receives the call. The call side transmission line is switched from the transmission line 52 to the transmission line 61, respectively. After the switching notification, the network management center 40 determines whether it is the last detour setting (step S8).
And end the procedure at the end.
Subsequent to S5, information on the next detour is transmitted to the calling station.

Next, FIG. 3 is a configuration diagram of a communication network showing an example of a scene of station congestion. In FIG. 3, the congested station 1 is an adjacent station on the calling station 2 and the transmission path 91, on the called station 3 and the transmission path 92, and on each of the relay stations 4.5 and the transmission paths 93 and 94. , Are connected respectively. The calling station 2 and the called station 3 are connected to a transmission line 95.
The transmission path 96 is between the relay stations 4 and 5, the transmission path 97 is between the calling station 2 and the relay station 4, and the transmission path 98 is between the called station 3 and the relay station 5.
The other relay station 6 is connected to each of the calling station 2 and the called station 3 via each of the transmission lines 99 and 90. These stations are connected to a network management center 7 via a network management information path 8.

Now, when the congestion station 1 notifies the network management center 7 of the occurrence of congestion, the network management center 7 notifies the congestion station 1 of data information of all relay calls, for example, an adjacent station as shown in FIG. Inquire and obtain the transmission path, logical channel and traffic volume. The network management center 7 uses the obtained data information in the detour setting means 41 (FIG. 1) to select a detour according to, for example, the procedure of FIG. 5 (described later). As a result of the processing, the calling station 2, the transmission path 91, the congestion station 1, the transmission path 92, and the called station 3
Network management center 7
The transmission path 95, the transmission path 99, the relay station 6, the transmission path 90, and the transmission path 97, the relay station 4, the transmission path 96, and the transmission path 95 do not pass through the congestion station 1 from the calling station 2 to the called station 3. Relay station 5 / transmission path
98 paths can be indexed from network management information. The network management center 7 performs one detour according to a predetermined detour setting standard,
When a packet path through the relay station 6 is selected, a call request packet (hereinafter referred to as a CR packet) to the relay station 6 via the transmission line 99 is sent to the calling station 2 and a detour code and a detour code are sent to the facility part of the CR packet. The information including the information of the detour relay station is transmitted. Since the relay station 6 recognizes the called station as the called station 3, the CR packet is transmitted to the called station 3 via the transmission line 90. The called station 3 returns a call accepting packet (hereinafter a CC packet) indicating that the call can be connected to the calling station 2 as the called station. Upon receiving the CC packet, the calling station 2 transmits a notification of completion of the formation of the packet link to the network management center 7.

When the setting of the packet link of the new path is completed, the adjacent stations of the calling station 2 and the called station 3 close windows on the path opposite to the congested station 1 and new data enters the congested station 1. And wait until the transmission of the pending data on the route of the adjacent station including the congested station 1 is completed. When there is no pending data, the congested station 1 and the adjacent station are connected to the network management center 7.
Tells that there is no pending data. Then, upon receiving this notification, the network management center 7 inquires of the adjacent station about the number of transmitted and received packets to maintain the normality of the data flow, and notifies the station on the new route of the response. As a result, it becomes possible to match variable values related to the data flow of the packet of each station. Finally, the network management center instructs the adjacent station to switch to a new route, opens a window, and resumes data transfer. As described above, congestion is alleviated by sequentially moving all detours to detours according to the instruction of the network management center and distributing traffic.

Next, with reference to FIG. 4, data information relating to a relay call possessed by each station will be described with reference to FIG. FIG. 4 is a data list showing an example of data relating to a relay call in a station.

In Figure 4, the call sign alpha ₁ of call calling station 2, the calling-side transmission path 91, the called-side transmission line 92, the called station 3, logical channel
l ₁ and the call volume β ₁ , and the call with the call code α ₂ has the same 91.92 from the calling station 2 to the called station 3, and the call code is only for the logical channel l ₂ and the traffic volume β _2. It is different from the α ₁ of the call.

Next, with reference to FIG. 5, a description will be given of the detour setting calculation means of FIG. FIG. 5 is a flowchart showing an example of a detour setting procedure.

First, the detour setting means calculates a coefficient of the traffic volume β which becomes equal to or less than the congestion value (for example, the usage rate of the processor of the station) K by the following equation (step S11).

β · k <K Expression 1 where Next, for each call α _i , a relay call α _j having a call amount exceeding a predetermined amount β (1-k) (see Equation 2) is selected in addition to the call amount β _i in descending order (step S12).

The detour setting means 41 enumerates the selected relay calls α _j (procedure S13), extracts the adjacent station from the relay data for one interrupted call α _j (procedure S14), and first calls the adjacent station. A route that does not pass through the congested station from the side station to the called side station is selected. When there are a plurality of selected routes, a route with a small traffic volume is selected as one switching route (procedure S15), and route switching is instructed to each of the calling station, the called station, and the congested station. . procedure
The procedure ends with the end of selection of the last relay call enumerated in S13 (procedure S16). If not, the adjacent station is taken out for the next enumerated relay call α _j (procedure S17), and the detour is performed. The procedure is connected to the procedure S15 for selecting a route.

〔The invention's effect〕

As described above, in the present invention, the network management center constantly monitors the congestion of the station, selects a predetermined number of relay calls from the relay calls passing through the congestion station when congestion occurs, and transmits the network management information of the network management center. By using this to determine an alternative route and form a link, and to divert those calls without disconnecting the calls, the operational improvement effect of reducing the traffic volume of congested stations and actively mitigating congestion can be achieved. is there.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an embodiment of a congestion mitigation method at the time of station congestion according to the present invention, FIG. 2 is a functional block connection diagram showing an example of a configuration for realizing FIG. 1, and FIG. FIG. 4 is a diagram showing an example of relay call data in a station, and FIG. 5 is a flowchart showing an example of a calculation procedure for setting a detour. 1,10 ... Congestion station, 2,20 ... Calling station (adjacent station), 3,30 ...
... Called station (adjacent station), 4, 5, 6 ... Relay station, 7, 40 ... Network management center, 51, 52, 91 to 99, 90 ... Transmission path.

Claims (1)

(57) [Claims] 1. A network management center coupled to each of a plurality of packet switching stations constituting one communication network by a network management information path, when a congestion information is received from one of said packet switching stations, switching is performed from this congestion station. Receives used line, logical channel, traffic volume, and information for identifying adjacent calling and called stations as relay call data during connection and satisfies one or more predetermined conditions from the relay calls And a switching path of the relay call selected on the transmission path connecting the calling station and the called station of the selected relay call, and at least information on the selected switching path is provided. When the switching path is set between the calling station and the called station by notifying the calling station, the connection path at the congested station of the set relay call is cut when the switching path is set. Switching to the switching path between the Congestion mitigation method at the time of the station congestion and butterflies.