JPH0685846A - Relay line bypass system - Google Patents

Abstract

PURPOSE:To select a relay line without causing a call interruption of a packet terminal equipment by providing a relay line communication control section having an exchange function between the X25 protocol and the frame relay protocol to the system. CONSTITUTION:X25C105, 122 are provided to the system, which implements speech control between PKT116, 129 in its own station and TRKC102, 119 having an exchange function between the X25 protocol and the frame relay protocol and has a re-transmission function of a layer 3 between other station and a communication control section. Then the frame relay protocol is adopted and the re-transmission control of the X25 protocol is implemented between the X25C105, 122 to prevent call interruption between the PKT116, 129.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay line bypass system for bypassing a relay line connecting nodes in a data exchange system.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing an example of a conventional data exchange system. Maintenance management control bus 107 for maintenance management control such as mounting and failure information, packet data,
DMA bus 208 for dividing program data into blocks to control data transfer, maintenance management control bus 107 and DM
Dedicated line 109 for communication between A bus 208 and other stations
And a network management control unit (hereinafter referred to as NW) that accommodates network management and implementation in its own station, and manages failure information.
C) 201, maintenance management control bus 107 and DMA bus 2
08 and a high-speed digital line 110 to accommodate a high-speed digital relay line communication control unit (hereinafter referred to as DTKC) 202 having a conversion function of an X25 procedure and an X75 procedure, a maintenance management control bus 107, and a DMA bus 208. A packet call control unit (hereinafter PKTC) 203 for performing data call control and packet data route control, a maintenance management control bus 107, a DMA bus 208, and an analog telephone network (hereinafter AL
(NW) 112 and the analog line 111 which accommodates the analog trunk line communication control unit (hereinafter referred to as ATKC) 204 having the conversion function of the X25 procedure and the X75 procedure, the maintenance management control bus 107, the DMA bus 208, and the ISDN 114.
The ISDN trunk line communication control unit (hereinafter, ISDNTC) 205 having the function of converting the X25 procedure and the X75 procedure by accommodating the ISDN line 113 connected to the It has an X25 communication control unit (hereinafter X25C) 206 that accommodates the packet line 115 connected to the PKT) 116 and controls communication with the PKT 116.

The X25 procedure is once terminated by the X25C206 from the PKT 116 through the packet line 115, and the DMA is executed.
The call control information is transmitted to the PKTC 203 via the bus 208. When the PKTC 203 determines that the other party is not the local packet terminal, the PKTC 203 sends the DTKC2 through the DMA bus 208.
02 is the DTK of the partner station through the high-speed digital line 110
Communicate with C by X75 procedure. In the partner station, although not shown, DTKC is PKTC, X25C through the DMA bus.
X25C is connected to the PKT of the partner station via the packet line of the partner station. If the high-speed digital line 110 cannot communicate due to a communication error, the DTK
The C202 is the NWC 20 through the maintenance management control bus 107.
1 is notified of a communication line error, and the NWC 201 is
NWC201 and the NWC of the partner station through 9
From the DMA bus 208, the ISDNTC 205 is instructed to perform a calling process, and the ISDNTC 205 makes a call to the ISDN 114 through the ISDN line 113 to send the ISN of the partner station.
Synchronize with SDNTC.

Next, from DTKC202 to ISDNTC2
Switch the trunk line to 05. At this time, the NWC 201 routes from the DTKC 202 to the ISDNT to the PKTC 203.
Instruct to switch to C205. X25C206
Since it cannot perform data communication during that time, it continues to return RNR to PKT 116, but tries to restart communication when the trunk line is switched. However, X25C206 is DTK
Since the procedure is once terminated at C202, and the procedure for retransmitting the packet data X75 is not held when the DTKC202 is switched to the ISDNTC205, a call disconnection occurs once between the PKT116 and the partner station PKT after the switching.

When an abnormality occurs in the ISDN line 113, the ATKC 204 is similarly switched, but a call disconnection also occurs at that time. The same applies when switching back to the original line when the line is restored.

[0006]

In this conventional data exchange system, since the relay communication procedure is X75 and the protocol is heavy, the relay line communication control unit accommodating the high-speed digital line and the analog circuit are required from the viewpoint of the processing capability of the processor. If the relay line communication control unit that accommodates the line and the relay line control unit connected to the ISDN are distributed, and if data communication cannot be performed due to a communication line error, the X75 switches to another relay line control unit. There is a problem that the packet terminal causes a call disconnection because the X25 communication control unit that cannot make a call and that controls communication with the packet terminal does not have a retransmission procedure between nodes.

Further, the network management control unit also needs to control many trunk line control units, and the packet call control unit also needs to change the call control route each time the trunk line control unit is switched. It was complicated.
Furthermore, X75 is connection-oriented, and communication is first synchronized between the trunk line control units, and then communication is resumed after synchronization is established between the X25 communication control unit and the trunk line control unit, so communication is restarted. There was a problem that it took time.

Furthermore, in the ISDN trunk line control unit, L
Since it has a conversion function of X25 procedure and X75 procedure in addition to the APD procedure, it cannot be shared with the communication control unit between the nodes of the ISDN terminal, so it must be separated from the trunk line communication control unit between the ISDN terminals. There is a problem that many communication control units are required.

[0009]

The relay circuit detour system of the present invention comprises a data exchange system of its own station and another station,
Each of the data exchange systems has a maintenance management control bus for maintenance management control such as mounting and failure information, a cell bus for cellizing packet data and program data to control data transfer, and data transfer control by allocating data to time slots. Network management control for accommodating a circuit switching bus for performing the above, a maintenance management control bus, the cell bus, and a dedicated line for performing communication with the other station, and for managing mounting / fault information in the own station Unit, the maintenance management control bus, the cell bus, and the circuit switching bus, and receives route selection information from the network management control unit through the cell bus to select a high-speed digital circuit, an analog circuit, or the circuit switching bus. Trunk line communication control having conversion function between X25 procedure and frame relay procedure A packet call control unit for accommodating the maintenance management control bus and the cell bus for call control of packet data; and an ISDN line communication for accommodating the maintenance management control bus, the cell bus and the circuit switching bus. A layer 3 retransmission function between an ISDN communication control unit for controlling, a communication control unit for accommodating the maintenance management control bus and the cell bus, and controlling communication with a packet terminal in the local station. And an X25 communication control unit having.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a relay circuit detour system of the present invention.

This embodiment comprises a node master data exchange system (hereinafter referred to as DTS) 100 and another node's DTS 117. Each DTS 100, 117 has a maintenance management control bus 107 for maintenance management control such as mounting and failure information.
124, and cell buses 108 and 125 that control packet data transfer by converting packet data and program data into cells,
It accommodates circuit switching buses 106 and 123 for allocating data to time slots to control data transfer, maintenance management control buses 107 and 124, cell buses 108 and 125, and a dedicated line 109 for communication with other stations. NWC1 that manages network management and implementation / fault information within its own station
01, 118, maintenance management control buses 107, 124, cell buses 108, 125, and circuit switching buses 106, 123 are housed in the NWCs 101, 118 to the cell buses 108,
High-speed digital line 110, analog lines 111 and 126, circuit switching bus 1
A trunk line communication control unit (hereinafter TRKC) 102, 119 having a conversion function between an X25 procedure and a frame relay procedure that can be switched to any of 06, 123, maintenance management control buses 107, 124, and cell buses 108, 125 are accommodated. PKTC 103 for performing call control of packet data,
An IS for accommodating the 120, the maintenance management control buses 107 and 124, the cell buses 108 and 125, and the circuit switching buses 106 and 123 to control the communication of the ISDN lines 113 and 127.
DN communication control units (hereinafter, ISDNC) 104 and 121,
Maintenance management control buses 107 and 124 and cell buses 108 and 1
25 and the X25C 105, 122 having a layer 3 retransmission function with the communication control unit of another station by controlling communication with the PKTs 116, 129 in the own station.

PKT11 of the node master DTS100
6 through X15C1 in the own station through the packet line 115
At 05, packet processing is performed. Call control information is transmitted from the X25C 105 to the PKTC 103 through the cell bus 108. When the PKTC 103 determines that the communication partner is outside the own station,
The call control information is transmitted to the TRKC 102 connected to the DTS 117 accommodating the PKT 129 through the cell bus 108. The TRKC 102 converts the X25 call control procedure into a frame relay procedure to convert the high-speed digital line 11
Call TRKC119 through 0. TRKC119
Convert frame relay procedure to X25 call control procedure with
Send to the PKTC 120 through the cell bus 125. P
From KTC120 through cellbus 125 to PKT116
Communicate with the other party's PKT129. PKT11
6 and the PKT129, when the link is established, the packet data does not pass through the PKTC 103, 120, and is directly transferred to the X25C.
105 through TRKC102 through TRKC119, X
Data communication is performed with the 25C122.

If a line abnormality occurs in the high-speed digital line 110 and communication cannot be performed, the node master T
The RKC 102 informs the NWC 101 of the DTS 100 of a communication error through the cell bus 108. The maintenance management control bus 107 for maintenance management control such as mounting and failure information is for detecting an abnormality in the communication control unit, and notifies a line abnormality or the like through the cell bus 108. The NWC 101 connects the ISDN line 11 to the ISDNC 104 through the cell bus 108.
3, the call is made to the ISDN C 121 of the DTS 117 connected to the ISDN line 127 through the ISDN 114.

When there is an incoming call from the ISDNC 104, the ISDNC 121 transmits the incoming call from the ISDNC 104 to the NWC 118 through the cell bus 125. NWC 118 uses circuit switching bus 1 according to the incoming call information from ISDNC 104.
Slot numbers corresponding to the data communication speed are given to the 23 time slots to the TRKC 119 and the ISDN C 121. At the same time, when the ISDNC 104 receives the call from the ISDNC 121, it notifies the NWC 101 of the completion of the call through the cell bus 108, and the NWC 101 sets the time slot of the circuit switching bus 106 to the slot number matching the data communication speed.
It is given to the RKC 102 and the ISDNC 104. TRKC1
02 is assigned a slot number from the high speed digital line 110 through the circuit switching bus 106 to the ISDN C1
04, ISDN line 113, ISDN 114, ISDN
C121, ISDN line 121, line switching bus 123,
Establish a route for TRKC119.

Since the frame relay procedure is performed between the TRKCs 102 and 119, the incoming / outgoing call information is disconnected. But,
Since the packet data has a retransmission procedure between the X25Cs 105 and 122, the retransmission procedure is repeated until the relay line switching is completed, and the RNR is sent to the PKTs 116 and 129 during that time. After switching is completed, PKTs 116, 1 are retransmitted by retransmission.
Communication between 29 is resumed and no call disconnection occurs.

The ISDN C104 and 121 are LAPDs.
The frame relay procedure is terminated between the TRKCs 102 and 119. PKT
C103 and 120 control only call control, and TRKC102 and 119 do not change even if the route of the trunk line is switched. Therefore, PKTC 103 and 120 need not be aware. Further, if a switching table of the route when the communication line is abnormal is defined in advance for the NWCs 101 and 118, there is no need to exchange information through the dedicated line 109 between the NWCs 101 and 118, and if switching is performed from the node master, another Can be synchronized with the node.

Further, the IS is connected between the ISDN C104 and 121.
When an abnormality occurs in the DN communication line, the ISDN C 104 reports it to the NWC 101 through the cell bus 108,
C101 is an analog line 11 to TRKC102
1. Call the TRKC 119 connected to the analog line 126 through the analog telephone network (hereinafter referred to as ALNW) 112. When the TRKC 119 receives a call, the TRKC 119 reports to the NWC 118 through the cell bus 125, closes the ISDN C 121, and deallocates the time slot. TRKC1 at the same time
When TRKC 119 receives a call, 02 reports the completion of calling to the NWC 101 through the cell bus 108. NWC
Upon receiving this information, the 101 blocks the ISDNC 104 and deallocates the time slot. This allows the relay to continue through the analog line. If the failure of the high speed digital line 110 is recovered, the TRKC 102 informs the NWC 101 of the recovery through the maintenance management control bus 107, and the TRKC 102 switches to the high speed digital line 110. The same applies to switching between the ISDNCs 104 and 121 after communication.

[0018]

As described above, according to the present invention, since the frame relay procedure is adopted in the trunk line communication control unit, the protocol is lightened, the number of lines accommodated with the same processor processing capacity is increased, and high speed digital lines and analog lines are provided. It can accommodate lines and circuit-switched buses at the same time. Further, since the frame relay procedure is adopted and the retransmission control of the X25 procedure is performed between the X25 communication control units, the call disconnection between the packet terminals does not occur. Furthermore, since a circuit-switched bus is adopted, frame relay data is transparently communicated via this circuit-switched bus when detouring to ISDN, so the ISDN communication control unit does not need to have a heavy protocol of X75, and voice systems and There is an advantage that other different data can also use this communication control unit. Furthermore, since packet call control supports only call control, many communication control units that manage call control can be accommodated. Further, since there is only one trunk line communication control unit, there is an effect that network management is not complicated.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a trunk line detour system of the present invention.

FIG. 2 is a block diagram showing an example of a conventional data exchange system.

[Explanation of symbols]

100,117,200 Data Exchange System (DT
S) 101, 118, 201 Network management control unit (NWC) 102, 119 Trunk line communication control unit (TRKC) 103, 120, 203 Packet call control unit (PKT)
C) 104,121 ISDN communication control unit (ISDNC) 105,122, 206 X25 communication control unit (X25
C) 106,123 Circuit switching bus 107,124 Maintenance management control bus 108,125 Cellbus 109 Private line 110 High speed digital line 111,126 Analog line 112 Analog telephone network (ALNW) 113,127 ISDN line 114 ISDN 115,128 Packet line 116,129 Packet terminal (PKT) 202 High-speed digital trunk line communication controller (DTK)
C) 204 analog trunk line communication controller (ATKC) 205 ISDN trunk line communication controller (ISDNT)
C) 208 DMA bus

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location H04L 12/48 H04M 3/00 D 8426-5K 8529-5K H04L 11/20 C

Claims (1)

[Claims] 1. A data exchange system for a local station and another station, each data exchange system comprising a maintenance management control bus for maintenance management control such as mounting and failure information, and packetized data and program data which are converted into cells to form data. It accommodates a cell bus for transfer control, a circuit switching bus for allocating data to time slots for data transfer control, and a dedicated line for communication between the maintenance management control bus, the cell bus, and the other station. A network management control unit that manages network management and implementation / fault information in the local station;
The maintenance management control bus, the cell bus, and the circuit switching bus are accommodated and route selection information is received from the network management control unit through the cell bus to switch to a high-speed digital circuit, an analog circuit, or the circuit switching bus. A trunk line communication control unit having a conversion function between an X25 procedure and a frame relay procedure, a packet call control unit that accommodates the maintenance management control bus and the cell bus, and performs call control of packet data, and the maintenance management control An ISDN communication control unit that accommodates a bus, the cell bus, and the circuit switching bus to control communication of an ISDN line; and communication control with a packet terminal in the own station that accommodates the maintenance management control bus and the cell bus And an X25 communication control unit having a layer 3 retransmission function with the communication control unit of the other station. Trunk line bypass system to.