JPH02170748A - System for updating routing table - Google Patents

Abstract

PURPOSE:To correctly update a routing table in a short time by automatically updating the contents of the routing tables of all signal stations in a common line signal network by means of a routing table updating request message a signal link is extended or removed. CONSTITUTION:The routing table updating request message is composed of a table 11, a header (H0) 12, a header (H1) 13, a table updating signal station code 14, a spare bit 15, a display of the number of relay stages 16 and a completion display 17. The routing table updating request message follows a processing algorithm to update the routing table and to transmit the message in the signal station to receive the message, and by updating the routing table and transmitting it to an adjoining station, the routing tables of all signal stations in the signal network are automatically updated successively. Thus, it does no take a time to update the routing table, and the possibility of a miss is also eliminated.

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention is based on the International Telegraph and Telephone Consultative Committee (CCITY)
A routing table that each signal station has when adding or removing a signal link that directly connects adjacent signal stations in a signal network to which the common line signal system represented by the common line signal system N0.7 of This is related to the update method.

(Prior art) Conventionally, as a data multiplex communication technology, for example,
There are those shown in JP-A No. 90234, JP-A-62-77734, and JP-A-62-69343. However, these techniques do not refer to common line signaling networks.

Usually, in a communication network, by adopting a common line signaling system as an inter-office signaling system, the transmission network and the signaling network can be separated both physically and logically.

Figure 11 shows an example of a common line signal network. In the figure, (71) is a signal link that is newly added or removed, and (a), (b), ..., (g) are signal links. station or signal relay station (hereinafter referred to as signal station), (72),...
(79) is a signal link connecting signal stations.

In the above configuration, each signal station receives a signal message from an adjacent signal station (hereinafter referred to as an adjacent station) that is directly connected by a signal link, and if the signal message is not addressed to the own station, the signal station In order to direct the signal message to the destination signal station indicated by the routing label, a signal link to be sent is selected.The information referred to for this purpose is called a routing table, which is provided independently for each signal station.

For example, for ease of explanation, the routing table of the signal station (f) is assumed to be composed of the signal link set table shown in FIG. 12 and the signal route set table shown in FIG. 13. For the same reason, each adjacent station is connected by one link set (including only one signal link). Furthermore, all the signal stations may be signal relay stations having only the function of relaying signal messages, or CCI
TT common line signaling system N. Although it may be a signal station having the user section function referred to in 7, it is simply referred to as a signal station here.

That is, FIG. 12 shows an example of a signal link set table constituting the routing table of the signal station (f), and shows the relationship between the signal link set directly connected to an adjacent station and whether or not the signal link set can be used. In FIG. 12, the adjacent station column shows the signal station codes (d) and (e), which are adjacent stations to the signal station (f), and the signal link set column shows the signal station codes (d) and (e), which are adjacent stations to the signal station (f). , (e) and (f
) and the signal link set numbers (78) and (79) are set. And, the usability tank is the signal station (f)
Possible (○
mark) is set, and if the setting fails, it is set to disabled.

In addition, FIG. 13 shows a signal route table that constitutes the routing table of the signal station (f), showing normal routes and detour routes for each receiving signal station (a signal station that can receive a signal message issued from a signal station). This shows the relationship between adjacent station codes corresponding to , and whether or not they can be used. This first
In the signal route table shown in FIG. 3, the signal station codes of all the destination signal stations for the signal station (f) are set in the destination signal tank. Normal and detour routes are determined for each arriving signal lap, but the normal route is the route that is normally used, and if the normal route becomes unavailable due to a failure etc., the first priority detour route is taken. Switch and use according to the following priority order. Furthermore, if a route with a higher priority than the route currently in use is restored, it will be switched back and used.

This behavior is recommended by CCITY and is recommended by C(:ITT
It is recommended that the route with the shortest number of relay link steps to the destination signal station be used as the normal route, and that detour routes should be given priority in descending order of the number of steps. In the usability tank of the signal route table, it is set whether the route is usable or not.

Next, to explain the case where a signal link (71) is added as shown in Fig. 11 in the existing signal network as described above, Fig. 14 shows the case where a new signal link (71) is installed. The signal link set table of the signal station (a) of
FIG. 15 shows the signal route set table, and the signal stations (a) and (b) to which the signal link (71) has been added are the signal stations (a) and (b) in FIG. 14 regarding the signal link set table.
As shown in the example of signal station (a), the table is updated to include information regarding the signal station (71), and the signal route set table is also updated, as shown in the example of signal station (a) in FIG. Signal station (b), (C),...
The table is updated with updated information regarding (f).

For other signal stations, only the signal route set table is updated.

(Problem to be Solved by the Invention) As described above, in the conventional example, updating the routing table when adding or removing a signal station is difficult when the signal link is added or removed.
Since the operator has to modify the routing table of not only the removed signal station but also all the signal stations, there are problems such as not only the time required but also the possibility of correction errors.

This invention was made in order to solve the above-mentioned problems, and when a signal link is added or removed, signal stations other than the signal station where the signal link was added or removed do not need to be operated by an operator. The purpose of this invention is to obtain a routing table updating method that can automatically update the routing table.

[Means to solve the problem]

The routing table updating method according to the present invention includes a plurality of signal stations having a common line signal transmission/reception function and a common line signal processing function, and connects the corresponding signal stations by a common line signal line called a signal link. A common channel signal network is constructed that is independent of the transmission network that carries information sent and received between originating and terminating users, and the signal station is used to route signaling messages from all the signal stations to the terminating signal station within the signal network. In a common channel signal network that is equipped with a routing table, the number of signal stations passed through each route to reach the destination signal station is stored in the routing table of the corresponding signal station as relay stage number information, and the number of signal stations that are passed through to reach the destination signal station for each corresponding route is stored as relay stage number information. When a change occurs in the signal route due to removal, a routing table update request message containing a routing table update signal, destination station code, and message relay stage number information is provided, and when the message is received, the routing table is updated and the message is sent. After updating the routing table according to the processing algorithm for transmitting the message to the adjacent station, the message is sent to the adjacent station, and the routing table of the corresponding signal station in the signal network is automatically updated sequentially. That is.

[Effect]

In the present invention, the routing table update request message is transmitted to an adjacent station by updating the routing table at the signal station where the message is received, and then updating the routing table according to a processing algorithm for transmitting the message. Routing tails of all signaling stations in the signaling network are updated sequentially.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the format of a routing table update request message according to the present invention, where (11) is a label containing the originating and terminating signal station code (standard 32 bits in CCITT), and (12) is a header HO1 indicating the type of message.
(13) is a header H1 indicating the type of signal included in the message, each of which is 4 bits in CCITT, and (14) is a signal station code for which the table is updated, which is 14 bits.

(16) is the relay stage number display bit (15 bits) that indicates the number of signal stations to be relayed before reaching the signal station updated by the route that received this message, (17)
is a bit (1 bit) that is displayed when a series of message transmissions is completed, and (15) is a reserved bit consisting of 2 bits.

Such a routing table update request message is provided to each signal station, and each signal station uses a processing algorithm for updating the routing table and transmitting the message to an adjacent station when receiving the message as described below. Accordingly, after updating the routing table, the message is sent to the adjacent station, and the routing table of each signaling station in the signaling network is automatically and sequentially updated.

Figure 2 shows the relay sequence side of the routing table update request message related to the common line signaling network shown in Figure 11, where the symbol before [) is the table update signal station code in the message, and the symbol in parentheses is the code for the above message. The number of relay stages in [
The * mark after ] indicates that the end display is ON.

Furthermore, FIGS. 3 and 5 show processing algorithms when a routing table update request message is received at a signal station where a signal link has been added/removed, respectively, and FIGS.
The figure shows a processing algorithm when a routing table update request is received at a station other than the signal station to which a signal link has been added/removed.

Furthermore, FIGS. 7 and 9 show the signal links (7) of the signal stations (a) and (d) in FIG.
1) shows the signal table before the addition of the signal link (71), and FIGS. 8 and 10 similarly show the signal route table after the signal link (71) is added. In these tables, the number of relay stages indicates the number of signal stations that the route passes through before reaching the incoming signal station.

Furthermore, the usability column is omitted because it is unnecessary for the subsequent explanation of the operation. The signal link set table was also omitted for the same reason.

Next, the operation of the above embodiment will be explained with reference to each drawing. Now, in FIG. 11, when a signal link (71) is added, the signal station (a) to which the signal link is added refers to the signal route table shown in FIG. 7 before the signal link is added. , sends a routing table update request message to the new adjacent signal station (b) via the signal link (71). At this time, the messages created are for all the terminating signal stations except signal station (b), and the number of relay stages for the message is 1 more than the number of relay stages shown in the normal route column of the table for each terminating calling station.
Show what you added. That is, as shown in the sequence of Fig. 2, for the signal station (C), the number of relay stages is 1,
3 for (d), 1 for (g). Then, the last message to be sent, the signal station (
For g), turn on the end display (* in the sequence shown in Figure 2). Signal station (b) also performs the same operation as (a).

The signal (a) that has received all the routing table update request messages (received the message whose end indication is ON) then operates according to the processing algorithm shown in FIG.

That is, in FIG. 3, the signal station (a) remains a cut point in the signal network (when the signal station is removed, it is divided into multiple networks) even after the signal link is added, so that the signal station (a) in step S31 is The determination is Yes, and step S
32 is executed. When the signal station (a) is removed, if the network that includes the signal station (b), that is, the own station (a) is removed, a signal link is added and the newly adjacent signal station (b) is removed. ), there are signal stations (C), (d), (e), and (f) in the new adjacent station side network, so
Add route information for these stations to the signal route table. At this time, for each called station, the number of relay stages display (16) shown in Figure 1 in the routing table update request message is compared with the number of relay stages in the signal route table, and the appropriate position in the table (the one with the smallest number of relay stages) is compared. is set so that the priority is higher). Further, the code of the signal station that sent the message is set in the adjacent hot water tank. When this setting is completed, the signal route table of the signal station (a) becomes as shown in FIG. 8, and the processes of steps S33 and S34 are executed with reference to this table.

In step S33, the signal station (
Routing table update request messages for b) and (d) are sent to all neighboring stations (b) and (C) except for neighboring station (b) through which the normal route passes. At this time, the number of relay stages for the message is displayed as the number of relay stages for the normal route in the signal route table plus one.

Then, in step 534, the routing table update request messages for the signal stations (e) and (f) whose first priority detour routes have been updated are sent to the signal stations (e) and (f).
) is transmitted to the adjacent station (C) via which the normal route passes.

At this time, the number of relay stages of the message is displayed as the number of relay stages of the first priority detour route in the signal route table plus one. Here, the first priority detour route for the signal station (C) has been updated, but the adjacent station (C) that this normal route passes through does not have route information about its own station (C). No message is sent. Note that in the case of the last message to be transmitted to each adjacent station, the message end display (17) is turned ON. Similarly, routing table update request messages are transmitted from the signal station (b) to (C) and (d).

Next, the operation when a signaling station other than the station to which the signaling link has been added receives the routing table update request message will be described for the signaling station (d). At the signal station (d), as shown in the relay sequence side entrance of FIG. 2, the routing table from the signal station (b) to the signal stations (a) and (g) is displayed with the number of relay stages being 1.2, respectively. Receive update request messages. After the signal station (d) receives the message whose end indication is ON, the signal station (d) sends the fourth signal.
It operates according to the processing algorithm shown in the figure.

That is, in FIG. 4, since the signal station (d) is not a cut point in the signal network, the determination in step S41 is NO, and step S45 is executed. In step S45, the signal route table is rewritten for all received messages. first,
Message processing for signal station (a) will be explained. In the table shown in FIG. 9 before the message is received, the route of the signal station (a) via the adjacent station (b) has two relay stages and is a detour route with the first priority. Since the number of relay stages for the routing table update request message is 1, this route has a smaller number of relay stages than the normal route passing through the adjacent station (e). Therefore, the normal route and detour route are swapped. signal station (g
), a similar operation occurs, and the signal route table shown in FIG. 1O is created.

Next, in step S43, the routing table update request message for the signaling station (a) and (gl) whose normal route has been changed is sent to all neighboring stations (e) except for the neighboring station (b) through which the normal route passes. , (f).At this time, the number of relay stages of the message is displayed as the number of relay stages of the normal route in the signal route tail plus one.Step 544 is performed because there is no corresponding signal station. , not processed.

If a signal link is added due to this kind of operation,
The routing tables of all signaling stations in the signaling network are updated.

If the number of relay stages equal to the number of relay stages of the routing table update request message exists in the signal route table, the signal route for that message is set to the lowest priority position of the signal routes with the same number of relay stages on the signal route table. be done. Further, whether or not the own station is a cut point can be easily determined from the signal route table. If the set of neighboring stations is the same for all incoming call stations in the signal route table, then the local station is not a cut point, but if there is an incoming call station with different elements, it becomes a cut point, and the local station is removed. When this happens, terminating call stations with the same elements will form a connected network.

Next, a process of updating the routing table when a signal link is removed will be explained.

The signal station whose signal link has been removed operates according to the processing algorithm shown in FIG.

First, when a signal link is removed in step 551, the signal route that had that signal link as part of the route is deleted from the signal route table, and for the signal station whose normal route was deleted, the new normal route is relayed. Display the number of stages plus 1 in a routing table update request message and send it to all neighboring stations (step 552).
, for signal stations whose first priority detour route has been deleted,
The number of relay stages of the new first priority detour route plus 1 is displayed in a routing table update request message, and the message is sent to the adjacent station through which the normal route passes.At this time, the detour route is added to the new signal route table. If the signal station is deleted, the adjacent station is notified of the deletion of the signal station using the message (information is set in header H) (step 553).

Additionally, if a signal station other than the station whose signal link was removed receives the routing table update request message,
It operates according to the processing algorithm shown in FIG. First, in step 5lit, the signal route table is updated for all received messages. At this time, if the message is to be deleted, the signal route passing through the station that transmitted the message is deleted from the signal route table.

If not, refer to the number of relay stages of the message and set the signal route to an appropriate position in the signal route table.Next, in step 562, for the signal station whose normal route number of relay stages has changed, a new normal route is set. The number of relay stages plus 1 is displayed in the message, and the message is sent to all neighboring stations except those on the normal route. For a signal station where the number of relay stages on the first priority detour route has changed, the number of relay stages on the new first priority detour route plus 1 is displayed in a message, and the message is sent to the adjacent station through which the normal route passes (step 563).

Through the above operations, when a signaling link is removed, the routing tables of all signaling stations in the signaling network are updated.

In the above embodiment, an end indication is added to the end of the routing table update request message to be sent.
Information on all signal stations to be updated may be included in one message, and the format label (11), header HO (12), and header H1 of the routing table update request message shown in Figure 341 in the above embodiment. (13)
The recommendations of CCITT were followed, but this is not limited. Furthermore, the shape of the signal network is not limited to that shown in FIG.

(Effects of the Invention) As described above, according to the present invention, when a signal route is changed due to addition/removal of a signal link, a routing table update request message is sent to update the routing tables of all signal stations in the common channel signal network. Since the contents are automatically updated, the routing tables of these signal stations within the common line signal network can be updated accurately in a short time.

[Brief explanation of the drawing]

FIG. 1 is a format diagram of a routing table update request message according to an embodiment of the present invention, FIG. 2 is a relay sequence diagram of a routing table update request message, and FIGS. 3 and 4 are signals with additional signal links. A flowchart showing the respective processing algorithms when a station and a signal station other than the station receive a routing table update request message. Flowcharts showing respective processing algorithms when a station receives a routing table. Figures 7 through 1θ are explanatory diagrams of updating the signal route table when adding a signal link, and Figures 7 and 8 are similar to Figure 11. Signal link (71)
The signal route table of the signal station (a) before and after the addition of the signal link (71), FIGS. 11, each showing a signal route table corresponding to the figure.
FIG. 12 is an explanatory diagram of an example of a common line signal network, and FIGS. 12 to 15 are explanatory diagrams of examples of a conventional routing table. FIGS. 14 and 15 respectively show the signal link set table and signal route set table of the signal station (a) when the signal link (71) in FIG. 7 is installed. In the figure, (71) is the No. 1 link to be added, from (a) to (
g) are signal stations in the common signal network, (72) to (79)
is the signal link, (11) to 17) are the label and header H in the routing table update request message, respectively.
O, header old, table update signal station code, spare bit, relay stage number display, end display. Note that the same reference numerals in each figure indicate the same or corresponding parts. Figure 3 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure A-9: J'! 79°a to number 71 Lua diagram procedural amendment (voluntary) March 27, 1999

Claims (1)

[Claims] It is equipped with multiple signal stations that have a common line signal transmission/reception function and a common line signal processing function, and the corresponding signal stations are connected by a common line signal line called a signal link to carry information sent and received between originating and receiving users. In a common line signal network that constitutes a common line signal network independent of the transmission network, and in which the corresponding signal station is provided with a routing table for routing the signal message from the originating station to the destination station within the signal network. ,
The number of signal stations passed through each corresponding route to reach the destination signal station is stored as relay stage number information in the routing table of the corresponding signal station, and when a change occurs in the signal route due to the addition or removal of a signal link, A routing table update request message including a routing table update signal, a destination station code, and message relay stage number information is provided, and when the message is received, the routing table is updated and the message is transmitted to an adjacent station according to a processing algorithm, A routing table updating method characterized in that after updating a routing table, the message is sent to an adjacent station to automatically and sequentially update the routing table of the corresponding signal station in the signal network.