JPH01264430A - Isdn packet switching system - Google Patents

Abstract

PURPOSE:To efficiently process a fault and system reopening so as to provide users with highly stable packet switching service by connecting maintenance information and subscriber's line state information to a packet switchboard in a time division multiplexed form. CONSTITUTION:Interface devices (U-INF) 1 and 2 respectively house digital subscriber's lines 3 and 4 of a (2B+D) basic access system and monitor states of layers 1 of the lines 3 and 4. The U-INFs 1 and 2 respectively separate B (B1 and B2) channels and D channels from each other and send the packets using the B channels to a packet switchboard 6 through a switch matrix 5 and the packets using the D channels to LAPD handlers 7 and 8. The U-INFs 1 and 2 also respectively send packets from the device 6 or handlers 7 and 8 to the subscriber's lines 3 and 4 and the packets form the handlers 7 and 8 monitor the termination and state of the layers 2 of the subscriber's lines 3 and 4.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an l5UN packet switching scheme.

[Conventional technology]

Conventionally, circuit switching equipment and packet switching equipment have been designed and installed as completely separate communication equipment. In recent years, CC
ITT's 181) N exchange system specification (CCITT Re
d book I 5eries) is recommended, and 2B+1) (B: 64Kbps) is recommended using an ordinary telephone subscriber line.
, L) : 16 Kbps) The digitalization of subscriber access using the basic access method is taking shape. In this switching system, the B channel is used to provide circuit switching services and packet switching services, and the D channel is used to provide signal control and low-speed packet switching services between the network and terminals. After a while,
The I5DN switch must handle circuit switching and packet switching in an integrated manner.

[Problem to be solved by the invention]

Generally, to achieve this, a packet switching device is placed after the time-division channel, and packet calls are routed to the packet switching device on the time-division channel, but in this case, the status of the digital subscriber line is This can only be seen indirectly, which not only complicates processing when a packet switching device fails or when starting up a system, but also makes it difficult to speed up processing.

[Means to solve the problem]

The 15DN packet switching system of the present invention is equipped with a packet switching device that processes packet calls for a plurality of 2B+D basic access digital subscriber lines, and transmits subscriber line status information and maintenance information over time-division communication channels using a time-division multiplexing system. The configuration is such that it is connected to the packet switching device via the packet switching device.

〔Example〕

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

Referring to the diagram illustrating one embodiment, the interface device y
It (U-INF) 1.2V12B+1) Accommodates basic access type digital subscribers N3 and 4, and monitors the status of layer 1 of digital subscriber lines 3 and 4. Also,
[J-INFI, 2 separates the (Bt l B2) channel and the D channel, and sends packets using the B channel to the packet switching device (PH) 6 via the switch matrix (SWMTX) 5, and Packets using channel I, APIJ handler (LAPD) 7
．． PH6 or LAPB7 respectively.
．． The packets from 8 are sent back to the digital subscriber line 3.4. The LAPB 7.8 performs layer 2 termination and status monitoring of the digital subscriber lines 3 and 4, transmits and receives call control signals to and from a call control processor (CP) 9, and performs statistical multiplexing and
Multiplexing and demultiplexing equipment (STMUX) 10 and 8 via WMTX 5 time-division multiplexes and multiplexes the status information and maintenance information of digital subscriber lines 3 and 4 autonomously in response to an information read request from PH 6 or when a failure occurs. Separation device (TDM)
11 and SWMTX5 to PH6. C.P.
9 controls SWMTX 5 and provides appropriate routing between digital subscriber line 3.4 and PH 6. PH6 is L
APB handler (LAPB) 12, 13, LAPD handler (LAPD) 14, and packet switch (PAW)
) 15. The LAPB 12 terminates layer 2 of the digital subscriber lines 3 and 4 and monitors their status. L.A.P.
B13 is used for communication with the Packet Switched Public Data Network (PSPDN) and provides layer 2 termination and status monitoring.

In a switching system with this configuration, a subscriber uses the B channel or D channel to communicate with other subscribers or PSPL.
) between the subscriber and this switching system or between the PSP DN and this switching system.
TT Recommendation I451, X25. Transmits and receives link level signals, call control signals, and packets in accordance with X75. In this switching system, link level signals are
B12.13 and LAPB7°8.14 process call control signals in CP9 and packets in P16, respectively, and perform appropriate routing and packet call setup. At this time, PH6 is a device used for the call set based on the received packet and information given from CP9.

Equipment number, routing and TDMII and SWMTX5
Identify the time-sharing channels and information used to communicate with each device via. From then on until the end of communication, the PH 6 periodically reads the digital subscriber line status information and maintenance information from each device to confirm normality. Furthermore, when each device detects a failure, it immediately reports the system status to the PH6.

Also, when starting up the system, the Pi-16
-INFI, 2, LAPB7, 8, 14 and LAP
Access B12.13 and connect digital subscriber line 3.
．． Check the normality of 4. The PH6 directly monitors failures in the digital subscriber lines 3 and 4 using the information obtained by operating in this way, and when a failure occurs, it handles the failure within the PH6, and also handles the failure in layers 1 and 4 of the digital subscriber lines 3 and 4. U-INFI, which is monitoring 2 and LAPL) 7, 8, or by making a fault handling request to CP9), efficiently handles the fault. deal with.

In the present invention, for details of the statistical multiplexing/demultiplexing device, reference can be made to the document "Data Communication Handbook" published by Ohmsha on October 30, 1981.

〔Effect of the invention〕

As explained above, according to the present invention, by connecting maintenance information and subscriber line status information to a packet switching device in a time division multiplex format, failure handling and system restart processing can be performed efficiently. A highly stable packet switching service can be provided.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of the present invention. 1.2...Interface device (U-INF), 3
．． 4... Digital subscriber Iwao, 5... Switch matrix (SWMTX), 6... Packet switching device (PR
). 7.8.14...LAPD handler (LAPD), 9
...Call control processor (CP), 10...Statistical multiplexing/demultiplexing device (STMUX), 11...Time division multiplexing/demultiplexing device (TL) (M), 12.13...LA
PB handler (LAPB), 15... packet switch (psw). , Patent Attorney Susumu Uchihara (

Claims (1)

[Claims] Equipped with a packet switching device that processes packet calls for a plurality of 2B+D basic access type digital subscriber lines, and connecting subscriber line status information and maintenance information to the packet switching device via a time-division communication path using a time-division multiplexing method. An ISDN packet switching system characterized by: