JP3140905B2 - Packet switching equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packet switching network in which a plurality of packet switching devices are interconnected by trunk lines.

[0002]

2. Description of the Related Art A conventional packet switching apparatus has realized a relay method as disclosed in, for example, Japanese Patent Laid-Open No. 1-196940. In this method, a logical relay route is set in advance between a packet transmission switching device and a packet reception switching device. That is, as shown in FIG. 11, for example, a logical relay route (ROT) between adjacent exchanges is defined on trunk lines 6 to 11 between the adjacent exchanges 1 to 5, and connection between the ROT and the intermediate exchange from the originating exchange is performed. A logical relay route to the destination exchange device is set, and this is set as the logical relay route between the destination and destination exchange devices (S
DROT). For example, in FIG. 11, the SDROT addressed to the switching device 1 to 4 is a ROT 12 on the trunk line 6,
The connection of the ROT 16 on the trunk 10 from the exchange 2 and the ROT 17 on the trunk 11 from the exchange 5
It is set as OT26. The originating exchange apparatus 1 uses the SDRO configuration table for the exchange apparatus 4 as shown in FIG.
T26 and the ROT 12 on the trunk line 6 are associated with each other, and the exchange device 2 sets the incoming RO corresponding to the incoming trunk line 6 as shown in FIG.
ROT12 on incoming trunk line 6 according to T-out ROT correspondence table
And the ROT 16 on the outgoing trunk line 10 are associated with each other.
ROT1 on incoming trunk 10 according to T-out ROT correspondence table
6 and the ROT 17 on the outgoing trunk line 11 are associated with each other. Such an SDROT is set in advance for each set of outgoing and incoming exchanges at the time of constructing the network, and each exchange outputs packets from the incoming trunk line based on the predetermined incoming ROT-out ROT correspondence table of each ROT. Transfer to a trunk line for relaying.

[0003]

In the packet switching apparatus having such a packet relay method, the source switching apparatus number, the trunk line number and the ROT number, the relay switching apparatus number, the SDROT configuration information for each SDROT are set in advance. Although it is necessary to store information such as the destination exchange device number and its connection relation, the SDROT that can be set increases as the shape of the network becomes more complicated.
The amount of OT configuration information is significantly increased and its management becomes difficult. SDROT is defined by the connection between the ROT between the originating and terminating exchanges and the transit exchange, and the transit exchange uses the SDROT.
There is a problem that if the failure occurs in the network because the originating and terminating exchange device of the DROT is not recognized, it is not possible to make a detour by switching the relay route unless the originating and exchanging device is notified. Also, when such an SDROT is newly set in the network, an appropriate trunk line from the originating and exchanging apparatus to the destination exchange apparatus and the connection between the unused ROT and the transit switching apparatus thereover are found and set as a new SDROT. There is a problem that operation is required and the setting method is complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and manages the SDROT setting information that each switching device should have without significantly increasing the amount of the information even if the network configuration becomes complicated. It is an object of the present invention to provide a packet switching device which realizes a packet relay method for facilitating the operation of the network and quickly performing a detour operation in the event of a network failure. Also,
An object of the present invention is to provide a packet switching device that can automate the setting operation when setting a new SDROT in a network.

[0005]

According to the present invention, a packet switching device includes an SDROT between each packet switching device.
ROT to adjacent packet switching equipment and adjacent packet exchange
From the switching device to the destination packet switching device as each destination
Each packet switching device is defined by a connection with the OT.
SDRO for each destination packet switching device in association with OT
A packet that has a T configuration table and is adjacent to the packet
ROT to packet switching equipment and address from neighboring packet switching equipment
For connection with SDROT to the destination packet switching equipment
It is configured by relaying more packets . Also,
The packet switching device according to the present invention is characterized in that the packet switching device or the packet switching device that detects the failure when a failure occurs in the trunk line uses another SDROT from the failure detection packet switching device that becomes unusable due to the failure. It is constituted by means for replacing the SDROT with a usable same destination packet switching device. Further, the packet switching apparatus according to the present invention includes, in its own packet switching apparatus, an unused R on a trunk line between the own packet switching apparatus and another packet switching apparatus adjacent to the packet switching apparatus.
OT to new SDRO for any other packet switching device
The reserved RO for the new SDROT configuration for the neighboring packet switching equipment
When a SDROT setting message packet containing a T number and the destination packet switching device number is transmitted and a response packet to the SDROT setting message packet is received from the adjacent packet switching device, the new SDROT is sent to the destination packet switching device. SDRO
Means for additionally setting as T, and said SDROT from a packet switching apparatus adjacent to said own packet switching apparatus.
Upon receiving the setting message packet, it recognizes the incoming trunk line number at which the message packet was received, the ROT number and the destination packet switching device number which are the contents of the message packet, and recognizes from the own packet switching device addressed to the destination packet switching device. One of the SDROTs, and stores the ROT on the incoming trunk line in correspondence with the secured SDROT from the own packet switching apparatus, and sends a response packet to the adjacent packet switching apparatus that transmitted the SDROT setting message packet. Return means. Further, the packet switching apparatus according to the present invention
Means for sending an SDROT setting instruction message packet containing an instruction to newly set an SDROT destined for another switching apparatus via the own packet switching apparatus to the adjacent packet switching apparatus; Means for, when receiving the SDROT setting instruction message packet from the device, performing the new SDROT setting by using an unused ROT on the incoming trunk line that has received the message packet.

[0006]

[Action] packet switching apparatus according to the invention, each Paquet
SDROT between packet switching devices is used for adjacent packet switching.
ROT to the device and each destination from the adjacent packet switching device
Connection with SDROT to destination packet switching equipment
In other words, each packet switching device associates with the ROT and
To reduce the SDROT configuration information of the whole network by have a SDROT configuration table of the previous packet switching device each, also the network failure in the event relay switching apparatus which detects the failure rapid change autonomously SDROT A detour operation can be realized. Furthermore, when a new SDROT is set, the setting procedure can be performed and set only with the adjacent packet switching device. The packet switching apparatus according to the present invention relays a packet from an originating packet switching apparatus to an adjacent switching apparatus using a destination correspondence SDROT at the time of packet transmission, and uses an SDROT from an adjacent switching apparatus corresponding to the SDROT from the adjacent switching apparatus. And relay it. Further, the packet switching apparatus according to the present invention replaces the SDROT in which, when a failure occurs, the packet switching apparatus that has detected the failure becomes unusable with another available SDROT addressed to the same destination packet switching apparatus. Further, the packet switching apparatus according to the present invention exchanges the SDROT setting message / response message with the adjacent packet switching apparatus, thereby performing the ROT between the own packet switching apparatus and the adjacent packet switching apparatus and the SOT from the adjacent packet switching apparatus.
A new SDROT is set in association with the DROT.
Further, the packet switching apparatus according to the present invention sends an SDROT setting instruction message to the adjacent packet switching apparatus, and sends a new S
DROT is set.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a diagram showing a packet switching network constituted by a packet switching device according to an embodiment of the present invention.
5 is a packet switching device of the present invention, 6 to 8 are packet switching devices (1) and (2), (1) and (3), (2) and (4), (3) and (4), (2) ) And (5), and trunk lines connecting (5) and (4), respectively, 12, 1
Reference numeral 3 denotes ROs to the adjacent packet switching devices (2) and (3) assigned to the packet switching device (4) on the trunk lines (6) and (7) from the packet switching device (1).
T, 14, 16 are adjacent packet switching devices (4), (5) assigned to the packet switching device (4) on the trunk lines (8), (10) from the packet switching device (2).
ROT to the adjacent packet switching device (4) assigned to the packet switching device (4) on the trunk line (9) from the packet switching device (3).
Is also the trunk line (11) from the packet switching device (5)
This is the ROT to the adjacent packet switching device (4) assigned to the above packet switching device (4). 21, 22,
27 is a packet switching device (2), (3),
SDRO composed of only one ROT (14), (15) and (17) addressed to packet switching device (4) from (5)
T. 20 is the ROT (1) to the packet switching device (5).
SDROT addressed to (4) from the packet switching device (2) defined by the connection between SDROT (6) and SDROT (27).
18 is an ROT (12) addressed to the packet switching device (2) and SD
SDROT addressed to the packet switching devices (1) to (4) defined by connection with the ROT (20), and 19 is packet switching defined by connection between the ROT (13) addressed to the packet switching device (3) and the SDROT (22). This is an SDROT addressed to the devices (1) to (4).

When relaying a packet from the packet switching apparatus 1 to 4, which SDROT is used by the outgoing packet is assigned in advance for each call when the call is set up. As shown in FIG. 2, each packet switching apparatus in the network determines which SDROT from the switching apparatus
It has an SDROT configuration table for each destination packet switching device indicating whether it is associated with OT. As shown in FIG. 3, a packet relayed in the network has a ROT information area as information for relaying in the network, and stores a ROT identification number of the SDROT used by the packet from the originating / switching device. I do. For example, for an outgoing packet addressed to the packet switching device 4, the SDR addressed to the switching device 4 illustrated in FIG.
The ROT to be stored is recognized from the OT configuration table. That is, in the figure, the SDROT 18 for the switching device 4
Since it is known a T 12 stores the identification number in the ROT information area of the outgoing packet is sent to the trunk line 6. Next, when the switching device 2 receives a packet storing the identification number of the ROT 12 from the trunk line 6, the incoming trunk line 6 ROT-SDROT correspondence table illustrated in FIG. Each one has.)
Recognizes that the ROT 12 is associated with the SDROT 20 addressed to the switching device 4. Next, as exemplified in FIG. 15 , the SDRO addressed to the switching device 4 in the switching device 2 similar to FIG.
Since the outgoing trunk line number and the ROT number constituting the SDROT 20 are known from the T configuration table, the ROT identification number (ROT 16 in the embodiment) is stored by rewriting the ROT information area of the received packet, and is stored in the outgoing trunk line (the trunk in the embodiment). On line 10). Hereinafter, the same relay operation is repeated in each relay switching device, and the packet is relayed to the destination switching device 4. By the above operation, each of the packet switching devices 1-4 can relay the packet by the relay processing of the same content as the conventional one, while the SDROT which should be possessed by the whole network
In the conventional example, the configuration information amount is the connection of all the components from the SDROT originating and exchanging device of the trunk line 6-ROT12-transit switching device 2-trunk line 10-ROT16-exchange device 5-transit line 11-ROT17 to the destination exchange device. Is SDROT configuration information, whereas in the present invention, the connection of trunk line 6-ROT12-transit switching apparatus 2-SDROT20 is SDROT configuration information, and the information to be managed is small.

Next, an operation when a failure occurs in the packet switching network shown in FIG. 1 and the switching device 2 detects the failure will be described with reference to FIG. When the switching device 2 detects a failure of the trunk line 10, the SDR from the switching device 2 that becomes a failure
Check OT. FIG. 5 shows SDROT addressed to switching device 4
In this embodiment, the corresponding SDROT 20 cannot be used. Next, the switching device 2 sends the SDROT 20 to the same switching device 4 for a normal SDROT 20 for the contents of all the SDROT configuration tables.
Replace with DROT21. As a result, the SDROT 18 from the switching device 1 is the same as the ROT 12 from the switching device 1, but the route from the switching device 2 is the ROT on the trunk line 8.
14 is changed to SDROT 21. As described above, the switching device 1 can normally continue the operation without the SDROT 15 being aware that the path changes in the switching device 2.

In addition, the SDROT in the above-mentioned transit switching device
The switching operation can be used not only when a failure occurs but also for load distribution of each SDROT or for congestion control. That is,
In FIG. 1, SDROT from the exchange 2 to the exchange 4
20 is associated with not only the SDROT 18 from the switching device 1 but also another SDROT, and if the traffic volume of the SDROT 18 becomes abnormally high, for example, the SDROT 18 from the switching device 1
Is switched to connect to SDROT21 and SDRO
Control to reduce the traffic amount of T20 is possible.

FIG. 6 shows an embodiment in which SDROT is newly set in a packet switching network constituted by the packet switching apparatus according to the present invention. now,
It is assumed that a trunk line 23 is newly added between the packet switching apparatuses 2 and 3 in the packet switching network illustrated in FIG. 1 to form a packet switching network as shown in FIG. Exchange device 3
As shown in FIG. 1, the SDROT 22 which is composed of the ROT 15 on the trunk line 9 already exists in the SDROT addressed to
When newly adding T, the operation is performed as follows.
When the switching device 3 sets a new SDROT destined for 4 using the trunk line 23, the switching device 3 sets the ROT 24 on the trunk line 23 as a new SDROT 25 destined for 4 and exchanges it as shown in FIG. It is stored in the SDROT configuration table for the device 4. Next, an SDROT setting message packet indicating that a new SDROT 25 for the switching device 4 is newly set using the ROT 24 on the trunk line 23 is sent to the switching device 2 (the SDROT setting message packet itself is addressed to the switching device 3 and 2). Relayed using existing SDROT). FIG. 8 shows a schematic configuration of the SDROT setting message packet. The contents of the SDROT setting message packet are a message identification information area indicating a SDROT setting message, a ROT number storage area, an SDROT number storage area, an SDROT destination switching apparatus number storage area, and the like. Consists of Upon receiving the SDROT setting message packet from the switching device 3, the packet switching device 2 selects the SDROT 21 addressed to the switching device 4 originating from the own switching device based on the destination switching device number in the packet, and The ROT number (ROT 24) in the packet is associated with the SDROT 21 in the ROT-SDROT correspondence table for the incoming trunk line 23 included in the switching device 2 as illustrated in FIG. Then, the switching device 2 sends a response packet to 3. Upon receiving the response packet, the switching device 3 determines the SDROT 25 by the ROT 24 on the trunk line 23 set previously. A new SDROT is set by the above operation. In the case where a procedure for setting a new SDROT from an adjacent switching device using the new SDROT is continuously performed, for example, in the above embodiment, for example, SDR in exchange 3
After the setting of the OT 25 is determined, an SDROT setting instruction message packet is sent to the adjacent switching device 1. SDROT
The content of the setting instruction message packet is an area for storing the destination switching device 4 number of the SDROT 25 set by the switching device 3 as illustrated in FIG. The switching device 1 that has received the SDROT setting instruction message packet knows from the contents of the packet that a new SDROT addressed to the switching devices 3 to 4 has been set, and the new switching device 4 that passes through the switching device 3 from the switching device 1. The destination SDROT setting is performed on the switching device 3. As described above, according to the present invention, when a new SDROT is set, it can be implemented only by exchanging with an adjacent switching device, and each ROT from a source switching device to a destination switching device via a relay switching device as in the related art It is not necessary to perform a procedure for setting the correspondence of each switching device.

[0012]

As described above, according to the present invention, each packet
SDROT between packet switching devices is used for adjacent packet switching.
ROT to the device and each destination from the adjacent packet switching device
Connection with SDROT to destination packet switching equipment
In other words, each packet switching device associates with the ROT and
Since the SDROT configuration table of the previous packet switching device each was to Yes, it is possible to reduce the SDROT configuration information amount for managing the entire network. Further, when a network failure occurs, the transit switching apparatus that has detected the failure can autonomously change the SDROT and realize a quick detour operation. Furthermore, when a new SDROT is set, it can be set only by exchanging with the adjacent switching device, and there is an effect that the SDROT setting operation can be simplified. Also, by instructing the adjacent switching device to set a new SDROT from the adjacent switching device via the own switching device, some SDROTs can be set.
Using the addition, all the switching devices in the network can use the additional SDROT.
, New SDROT setting can be performed.

[Brief description of the drawings]

FIG. 1 is a network configuration diagram showing a packet relay method according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an SD included in a switching device 1 according to an embodiment of the present invention.
It is a ROT composition table.

FIG. 3 is a diagram showing an example of an intra-network relay packet R according to an embodiment of the present invention;
It is a figure showing an OT information field.

FIG. 4 is a diagram showing an RO included in a switching device 2 according to an embodiment of the present invention;
It is a T-SDROT correspondence table.

FIG. 5 shows an SDR when a network failure occurs according to an embodiment of the present invention.
It is a figure showing the example of OT change.

FIG. 6 is a diagram showing a new SDROT setting procedure addressed to the switching device 3 to 4 according to the embodiment of the present invention.

FIG. 7 is an SDROT configuration table for the switching device 4 included in the switching device 3 according to the embodiment of the present invention.

FIG. 8 is a diagram illustrating an SDROT setting message packet format according to an embodiment of the present invention.

FIG. 9 is a ROT-SDROT correspondence table for the incoming trunk line 23 included in the switching apparatus 2 according to the embodiment of the present invention.

FIG. 10 is a diagram showing an SDROT setting instruction message packet format according to an embodiment of the present invention.

FIG. 11 is a diagram showing a packet relay method by a conventional packet switching device.

FIG. 12 shows a switching device 4 of the conventional packet switching device 1.
It is a destination SDROT configuration table.

FIG. 13 is an incoming trunk ROT-outgoing trunk ROT correspondence table of the conventional packet switching devices 2 and 5;

FIG. 14 is a correspondence table between incoming trunk line ROT and outgoing trunk line ROT of the conventional packet switching apparatuses 2 and 5;

FIG. S possessed by the switching device 2 according to the embodiment of the present invention
It is a DROT composition table.

[Explanation of symbols]

1-5 Packet switching device 6-11,23 Trunk line 12-17,24 Logical relay route (RO) between adjacent switching devices
T) 18-22, 25, 26 Logical transit route (SDROT) between originating and terminating switching equipment

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-229941 (JP, A) JP-A-2-166855 (JP, A) JP-A-62-198239 (JP, A) JP-A-63-198239 202157 (JP, A) JP-A-63-217746 (JP, A) JP-A-6-85813 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04L 12/56 H04L 12 / 28

Claims (4)

(57) [Claims] 1. A network comprising a plurality of packet switching devices for transmitting and exchanging data in a packet format and interconnecting them by trunk lines to form a network. A relay route (hereinafter abbreviated as ROT) between adjacent switching devices is defined, and the ROT and the packet switching devices constituting the network are alternately connected to each other to connect between the originating and terminating switching devices from the originating packet switching device to the destination packet switching device. In a packet switching device having a packet relay method for defining a relay route (hereinafter abbreviated as SDROT) and transferring a packet addressed to the destination packet switching device by the SDROT , the SDROT between the packet switching devices is transmitted to an adjacent packet switching device. SDRO and a of ROT said adjacent packet switching apparatus to the destination packet switching device as a respective destination It is defined by the connection of the respective packet switching device, each in association with the ROT
A packet switching device having an SDROT configuration table for each destination packet switching device and adjacent to the source packet switching device
ROT and destination from the neighboring packet switching equipment
A packet switching device for relaying a packet by connection with an SDROT to a destination packet switching device. 2. An SDRO from a packet switching device or a fault detecting packet switching device which detects a fault when a fault occurs in a trunk line and becomes unusable due to the fault.
T for another available same destination packet switching device
The packet switching device according to claim 1, wherein T is replaced with T. 3. An ROT that is not used on a trunk between an own packet switching apparatus and another packet switching apparatus adjacent to the packet switching apparatus is included in an own packet switching apparatus. SD for setting a new SDROT destined for the destination and for the adjacent packet switching device containing the reserved ROT number and the destination packet switching device number for the new SDROT setting
A new SDR when transmitting a ROT setting message packet and receiving a response packet to the SDROT setting message packet from the adjacent packet switching device;
Means for additionally setting an OT as an SDROT for the destination packet switching device, and an incoming trunk line number from which the SDROT setting message packet was received when the SDROT setting message packet was received from a packet switching device adjacent to the own packet switching device , And recognizes the ROT number and the destination packet switching device number which are the contents of the message packet, secures one SDROT from the own packet switching device destined for the destination packet switching device, and secures the ROT on the incoming trunk line with the ROT. Means for storing the SDROT from its own packet switching device in association with the SDROT and returning a response packet to the adjacent packet switching device which transmitted the SDROT setting message packet. The packet switching device according to the above. 4. A means for sending an SDROT setting instruction message packet containing an instruction to newly set an SDROT destined for another switching apparatus passing through the own packet switching apparatus to the adjacent packet switching apparatus. And when the own packet switching device receives the SDROT setting instruction message packet from an adjacent packet switching device, performs the new SDROT setting using an unused ROT on an incoming trunk line that received the message packet. 4. The packet switching device according to claim 3, further comprising: