JP2000069013A - Communication control method for atm-m bus system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable communication on an M bus in an ATM-M bus system without interposing any switch. SOLUTION: Concerning a communication method for the TM-M bus system composed of a gateway 1, M bus 3 composed of outgoing and incoming buses both terminals of which are accommodated in the gateway 1 and which return at the most distant end and plural branches 5 serially connected to this M bus 3, in such a configuration, the branchers 5 have a function for transforming the GFC/VP/VC with terminal equipment 9 under their control to a GFC/VP/VC on the M bus, and the gateway 1 has a function for transforming the GFC/VP/ VC on the M bus of a received cell to a GFC/VP/VC in the gateway and a function for judging whether it is the communication the M bus or not and when it is the communication on the M bus, the cell is sent to the brancher of the other party.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ATM (Asynchro
nous Transfer Mode: As for the communication control method of the bus system applied to the switching system,
Communication between a plurality of terminal devices under a branch device connected to the ATM-M bus, and communication between a terminal device under a certain branch device and a terminal device under another branch device; and Terminal device and ATM under branch device
The present invention relates to a communication control method for communication with a WAN connected to an M bus via a gateway.

[0002]

2. Description of the Related Art In the application of Japanese Patent Application No. 9-10231, the present applicant comprises a main device having an ATM switch and an ATM 155 Mbps interface, and a plurality of branching devices accommodated in series in the main device. The branching device accommodates a terminal device and is connected to an upstream bus and a downstream bus of the ATM 155 Mbps interface, and the terminal of the downstream bus is folded back to be an "AT bus".
A bus system called "MU bus system" has been proposed.

The U bus main unit used in this bus system converts all audio / video / data and the like into ATM cells and converts them into 155M cells.
A unique ATM bus interface (I /
F), a plurality of standard ATM terminals are accommodated thereunder, and a high-speed ATM terminal is accommodated directly in its port, whereby the ATM device is compatible with small offices and exchanges centrally. FIG. 10 shows the configuration of a U-bus main unit for a small business employing the U-bus system. The U bus main device 100 has a function as an ATM switching device, and has an ATM switch (ATM-SW) 101,
5 Mbps ATM Interface with U-GFC Control 10
2 and 100M (not shown).
It comprises a bps LAN interface, an existing WAN interface, a control unit, and a power supply unit having a storage battery.

ATM switch (ATM-SW) 101
Is similar to a normal ATM switch. In this example,
It has eight ports of 155 Mbps.

[0005] U bus main unit (ATM exchange) 100-1
The 55 Mbps ATM interface 102 is connected to the U bus 1
20 and ATM155Mbps terminal and ATM15
It is an interface package that can directly accommodate a 5 Mbps line, and has a U-GFC control function using a GFC portion provided in the header of an ATM cell.

The ATM interface 102 converts a GFC, a virtual path (VP), and a virtual channel (VC) in an ATM cell and adds a tag for switching, and a VP / VC conversion means;
A 155 Mbps ATM unit which is a user network interface of the Mbps specification, an optical / electrical conversion interface, and a reference table (G / VP) for VP / VC conversion
FC (including FC), and U-
A U-GFC control unit that performs GFC control is formed, for example, in a card-shaped package.

[0007] The U-GFC control unit includes a downstream cell FIFO memory for storing an ATM cell (down cell) ID to be sent to the downstream bus, and an upstream cell I / O memory received from the upstream bus.
It has an upstream cell FIFOI memory for recording D, and a comparing means for checking whether the downstream cell ID stored in the downstream cell FIFO memory matches the upstream cell ID stored in the upstream cell FIFO memory.

[0008] ATM 155 Mbps interface 102
Has an ATM bus 120 called an U bus, an ATM terminal, another ATM exchange via an ATM-PNNI, and an AT.
The ATM-WAN is connected via the M-UNI. An existing LAN network of 100 Mbps is connected to the LAN interface. Further, the existing WAN interface is connected to an ISDN line or an analog line, a dedicated line, an OCN, or the like.

The control unit controls the exchange control, package control, and network management of the U bus main unit 100.

The U bus 120 is a bus to which an ATM terminal can be connected, and is an ATM 1 with U-GFC control.
It is accommodated in a 55 Mbps interface 102. The U-bus 120 includes, for example, a 25 Mbps ATM key telephone (ATM-
KT) 151, 155 Mbps ATM terminal 152, 3.1
Analog telephone 1 with KHz audio (64Kbps)
53, ISDN terminal 154, 25 Mbps ATM terminal 1
55 is connected via the branching device 130, the analog telephone 153, the ISDN terminal 154, etc. are connected via the existing terminal branching device 133-3, and further the ATM terminal 152 such as a 155 Mbps server / computer is connected.

For example, the U-bus 120 includes the branching device 13
155 Mbps through 0-1, 130-2, 130-n
s ATM terminal 152, 25 Mbps ATM terminal 155, AT
M key telephone 151 etc. are U bus 12 of 155Mbps.
A plurality of connections are made in consideration of 0 traffic capacity.

As an interface accommodated exclusively for the U bus, there is an ATM key telephone (ATM-KT) which is a multi-function key telephone. This ATM key telephone is
The telephone has a CLAD inside and is connected to the U bus 120 by an ATM 25 bps interface.

As described above, in the ATM-U bus system, an identifier is given to each branching device, and the GFC (general flow control) field of the header of the ATM cell sent from the main unit is used to store the ATM cell destination branching device. And sends it out. In addition, the ATM-U bus system allows the branching device to branch the cell addressed to itself and send it to the terminal device. When there is no transmission data from the terminal device accommodated in the branching device, the branching device receives the cell. Deletes the identifier of the self-addressed cell destined for itself and sends it to the downstream node as an empty cell, and when there is transmission data from the terminal device accommodated in the branch device, the transmission data is transmitted to the self-addressed cell or the empty cell received by the branch device. And send it out.

In the ATM-U bus system, a plurality of transmission buffers for temporarily storing transmission data from a terminal device are provided in a branching device, and when the value of the transmission buffer reaches a predetermined value, the destination of the branching device is addressed. Is returned to the main unit as a "SOS" cell, and upon receiving the "SOS" cell, the main unit forcibly transmits a reserved vacant cell in which the identifier of the branching device is assigned to a downstream cell other than the shared channel. I have to.

The branching device used in the ATM-U bus system is as follows.
Connected to an ATM-U bus, and an upstream interface;
A function of having a downstream interface and an input / output interface to the terminal device, extracting an identifier given to the header of the received ATM cell, and branching the cell addressed to itself;
A bus control unit having a cell disassembly / assembly (CLAD) function and a cell insertion function for placing transmission data in a cell addressed to itself or an empty cell is provided.

ATM155 used for ATM-U bus system
The Mbps interface is connected to an ATM bus, and stores an identifier attached to the GFC of the ATM cell to be transmitted to the downstream bus, a FIFO memory for storing an identifier attached to the GFC of the ATM cell received on the upstream bus, Means for comparing the identifier attached to the GFC of the ATM cell transmitted to the downstream bus with the identifier attached to the GFC of the ATM cell received on the upstream bus; There is a function of allocating an empty cell specifying a terminal device to the downstream bus when the identifier attached to the GFC of the ATM cell received on the upstream bus is stored without storing the identifier.

This ATM-U bus system can be realized by using a standard ATM-switch (SW). Each 155 Mbps interface of the main unit ignores or invalidates the "M-GFC flow control". By doing so, it can be used as a standard ATM 155 Mbps port, and the terminal device of each branching device can transmit fairly and efficiently, and can guarantee the characteristics such as the maximum cell delay as much as possible. For symmetric services such as voice, such as existing terminals, transmission can be guaranteed only by the receiving cells of the terminal. For asymmetric services such as server access and Internet access, U-GFC flow control and "SO
The cell can be effectively used by the "S" cell. The terminal device on the U bus can perform "multicast" communication. The terminal device can be connected to the multipoint under the branch device. With the CLAD Existing terminal devices can be directly accommodated by connecting a branching device.U-bus system software processing is hardly necessary except for initial setting, OAM management, and U-bus management. The hardware is simply provided with an ATM 155 Mbps interface, and only increases the UTOPIA bus control, cell insertion / branching, and buffer processing, so that the U bus system can be easily realized. It is a method that has an excellent effect that it can be done.

In the above ATM-U bus system, it is necessary to communicate via an ATM switch even when communicating between branching devices connected to the bus.

[0019]

SUMMARY OF THE INVENTION The present invention relates to the above ATM.
In a U bus system (hereinafter referred to as an ATM-M bus system), communication between terminal devices under the same branch device without passing through an ATM switch;
Communication between terminal devices under different branch devices connected to the same ATM-M bus, and communication between terminal devices under the branch device connected to the ATM-M bus and WAN can be performed. An object of the present invention is to provide a communication control method.

[0020]

In order to solve the above problems, the present invention provides a gateway, an M bus having both ends accommodated in the gateway and turned back at the farthest end to form a down bus and an up bus. In a communication method of an ATM-M bus system comprising a plurality of branch devices connected in series to the M bus, the branch device uses G for communication with a subordinate terminal device.
FC / VP / VC and GFC / VP /
It has the function of converting between VC and VC,
The GFC / VP / VC of the cell transmitted on the down bus or the cell received on the up bus is used for the GFC / VP used on the M bus.
VP / VC and GFC / VP / V used in the gateway
C and a function to determine whether a cell received on the upstream bus is a communication on the M bus, and a function for determining whether a cell received on the upstream bus is a communication on the M bus. At one time, the received cell is transmitted to the other branching device via the down bus.

The present invention also provides a gateway, an M bus having both ends accommodated in the gateway and turned at the farthest end to form a down bus and an up bus, and a plurality of branches connected in series to the M bus. In a communication method of an ATM-M bus system including a device and a WAN connected to a gateway, a branch device uses a GF used between a subordinate terminal device.
C / VP / VC and GFC / VP / V used on M bus
C has a function of converting the GFC / VP / VC of the cell transmitted on the down bus or the GFC / VP / VC of the cell received on the up bus into the GFC / V used on the M bus.
GFC / VP / VC used in P / VC and gateway
And a function of determining whether a cell received on the upstream bus is for communication with the WAN, and a function for determining whether the cell received on the upstream bus is for communication with the WAN. , Cells are sent to the WAN.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ATM-M according to the present invention will be described.
An embodiment of a communication control method for a bus system will be described with reference to the drawings.

The present invention relates to the above-mentioned ATM-
An ATM-M bus system, which includes a multimedia bus (hereinafter, referred to as an M bus), a gateway, and a terminal interface branching device (hereinafter, simply referred to as a branching device), is adopted. The present invention relates to a communication control method. The branching device used for the ATM-M bus system according to the present invention includes an ATM 25 Mbps terminal device and an ATM 155 Mb
It is a branching device that can support multimedia such as ps terminal equipment, and is 25 Mbps for ATM key telephones.
It accommodates ATM terminals, 155 Mbps dedicated ATM terminals, general-purpose ATM terminals, and the like. MBU
Transmits and receives ATM cells to and from the branching device.

The outline of the ATM-M bus system according to the present invention will be described with reference to FIG. ATM-M bus method is WA
An M bus main unit (hereinafter referred to as a gateway) 1 which is connected to the N and M buses and has a function as a gateway for performing communication control within the ATM-M bus and WAN interface control, an M bus 3 of 155 Mbps, and an M bus 3 It is composed of a plurality of branching devices 5 connected in series. The branching device 5 has a plurality of 25 Mbps ports and is directly connected to a 25 Mbps ATM terminal device 91 such as an ATM telephone or a 25 Mbps ATM standard terminal device 92. Or LAN emulation client (LAN Emulation Cliant:
A personal computer (PC) 93 connected to an existing LAN (Ethernet) via a bridge 7 (hereinafter referred to as LEC) is accommodated.

The configuration and function of the gateway 1 will be described with reference to FIG. Gateway 1 is 155Mbps UN
It has an M bus interface function of I, an M-GFC control function for managing and controlling the M bus, a signaling control (Q2931) function of an ATM terminal, an address conversion function, a failure monitoring function of the M bus, and an interface function with a WAN. . Further, the gateway 1 transmits a TCP (Transmission)
Convergence Sublayer Protocol) / IP (Internet Pr
otocol) related LEC server functions (LAN EmulationServ
er: LES) and broadcast function
(Broadcast and Unknown Server: BUS)
Also supports.

In the LES function, a dedicated control channel (VPI / VCI) is set at the time of startup, and the medium access control (Me
dia Access Control: Function to resolve ATM address from ATM address to ATM address (LAN Em
ulation Address ResolutionProtocol: LEA
RP) and LE ARP tables.

The BUS function is performed by determining a cell in the M bus by signaling, referring to the GFC / VP / VC conversion table, and transmitting a broadcast cell in which the GFC is set to "15".

The gateway 1 includes a cell controller 11 and A
TM user network interface
Interface (hereinafter referred to as UNI)
Interface 13 for electrical conversion, GFC / VP / VC
A conversion function unit (hereinafter referred to as ATC) 14 and a CPU 15
, ROM 16, RAM 17, and AAL (ATM Ada
(ptation layer) 5 The controller includes a controller 18, a WAN interface circuit 19, and an SOS change table 20.

The cell control unit 11 is mounted on a programmable logic device (hereinafter, referred to as a PLD).
The M-GFC control unit 111 has a function of controlling communication on the bus 3, a cell assembling unit 112 for demultiplexing cells transmitted on the M bus 3 and to the WAN, and a multiplexer 113. In the cell control unit 11, M
-Transmission from the GFC control unit 111, transmission from the WAN interface 19, and transmission from the AAL5 controller 18 pass through the GFC / VP / PC conversion unit 14 once,
The GFC / VP / VC is converted with reference to the ATC table, and is converted to the down bus of the M bus 3 through the cell assembling means 112 or to the W through the WAN interface circuit 19.
Sent to AN.

The ATM user network interface 12 is an SDH STM1 (Synchronous Digital Hier
It is mounted on a dedicated LSI compliant with achy Syncronou Transfer Mode 1) (155 Mbps).

The optical / electrical conversion interface 13 is M
This is an interface with the M bus (155 Mbps) 3 using the MF.

The GFC / VP / VC converter 14 has a routing table (ATC table). G
The FC / VP / VC conversion unit 14 refers to the ATC table to convert the GFC / VP / VC of the received cell into the GFC / VP / VC of the destination cell.
A means for executing the conversion process, which is a routing-specific L
Mounted on SI.

The CPU 15 controls the cell control unit 11, the GFC /
VP / VC conversion means 14, AAL5 controller 18,
It controls the WAN interface circuit 19 and the like. ROM
16 stores software required for control performed by the CPU, and the RAM 17 stores data used for controlling the CPU.

The cell control unit 11 and the ATM UNI 12
, GFC / VP / VC conversion means 14 and CPU 15
The ROM 16, the RAM 17, the AAL5 controller 18, and the WAN interface circuit 19 exchange signals and data with each other via a bus.

The AAL5 controller 18 performs Q2931 signaling transmission / reception with a terminal device on the M bus, and performs control for dividing continuous data into 53-byte ATM cells for transmission.

The WAN interface circuit 19 has a WAN
To convert ATM cells sent to the WAN interface according to the WAN interface, or
An operation of converting to M cells is performed. The WAN interface circuit 19 is INS64 or INS1 of N-ISDN.
500, digital line T1, frame relay line, etc. Since the WAN interface circuit 19 accommodates a plurality of lines, the transmission circuit to the M bus is multi-connected, but is solved by daisy-chaining the AAL controllers included in the WAN interface circuit 19.

The SOS change table 20 is a table which is normally constituted by a RAM and generates a GFC from the VP / VC of the SOS cell and generates a reserved cell when an SOS cell described later is received by the gateway 1.

The configuration and function of the WAN interface circuit 19 will be described with reference to FIG. 3 as an N-ISDN INS64 interface. The WAN interface circuit 19 includes a CPU 191, a ROM 192, and a RAM 19
3, an INS64 transceiver 194, a pulse transformer 195, and an AAL controller 196.

The data cell interfaces with the CPU 15 via the AAL5 controller 18 for data communication. The B channel conversion of INS64 is performed by software, and PPP (Poit-to-
point Protocol).

The voice cell uses the SCC port of the CPU 15 via the AAL1 controller, and uses the internal RAM 193
The conversion to the B channel of the INS64 interface is performed by data transfer in the CPU.

CPU (upper control unit) 1 of gateway 1
5 is an interface with a control cell via the UTOPIA bus. Mainly ATM signaling (Q293
1) and INS net signaling (Q931).

The flow control of the TCP / IP communication is performed by the WAN
This is performed by the CPU 191 of the interface circuit 19.

A multimode optical fiber (hereinafter referred to as MMF)
The M bus 3 is configured as a 155 Mbps bus composed of two types of buses, a down bus sent out from the gateway 1 and an up bus when returning to the gateway 1, and the down bus is a turnback device at the farthest end. It returns at 31 and returns as an up bus. The GFC control of the communication in the M bus 3 is controlled unique to the M bus. Less than,
GFC control unique to the M bus is called M-GFC control.

A maximum of 14 branching devices 5 are connected in series to the down bus and the up bus of the M bus 3, respectively, and identification numbers are sequentially given to the branching devices near the gateway 1.
The branching device 5 has a function of relaying ATM cells received on the downstream bus downstream, a function of relaying ATM cells received on the upstream bus upstream, and a function of transmitting ATM cells received on the downstream bus addressed to itself.
It has a function of taking in cells and a function of sending data from a terminal device to empty cells. Also, the branching device 5 performs the VPI / V of the corresponding user cell by signaling.
It has a CI acquisition and management function, a GFC control function for the corresponding user cell, and a fault monitoring function for the M bus and terminal interface ports.

Further, the branching device 5 has a 155 Mbps terminal interface port or a plurality of 25 Mbps terminal interface ports. Each branching device 5 has a 25 Mbps ATM key telephone (ATM-KT)
A 91, 25 Mbps ATM standard terminal device 92 or a terminal device (PC) 93 connected to Ethernet is connected. The Ethernet is accommodated in the branching device 5 via the LEC bridge.

The branching device 5 includes a branching device 155M having a terminal interface port of 155 Mbps and a branching device 155M having a terminal interface port of 25 Mbps.
There is a branching device 25M having a terminal interface port of No. The branching device 155M is a branching device for connecting one port of a 155 Mbps ATM terminal device to the M bus 3 provided by the gateway 1. The branching device 25M is connected to the M bus 3 provided by the gateway 1 by the LEC bridge 7 or the ATM button telephone 91 or 25 Mb of 25 Mbps.
This is a branching device that connects the psATM standard terminal device 92 to, for example, four ports. Branching device 155M and branching device 25M
Can be accommodated on a single M bus up to a maximum of 14 units.

The block configuration of the branching device 155M will be described with reference to FIG. The 155 Mbps branching device 5 includes three optical / electrical conversion interfaces 50 connected to the M bus 3 and the 155 Mbps ATM terminal, and three ATM user network interface units (ATM UN).
I) 51, cell add / drop controller 52, cell add / drop controller control ROM 53, F-ROM 54, RAM
55, CPU 56, LED display unit 57, AC / D
It has a C converter 58 and a reset circuit 59. The optical / electrical conversion interface 50 is configured by a pulse transformer when the M bus 3 is configured by UTP.

The block configuration of the branching device 25M will be described with reference to FIG. The branching device 5 is connected to the M bus 3
Optical / electrical conversion interfaces 50-1, 50-2
And two 155 Mbps ATM user network interface units (ATM UNI) 51-1 and 51
-2 and multiple 25Mbps ATM UNI51-3-
1, 51-3-2, 51-3-3, cell branching / insertion /
Distribution / assembly control unit 52 and cell add / drop control unit R
OM 53, F-ROM 54, RAM 55, CPU
56, LED display unit 57, AC / DC converter 5
, A reset circuit 59, and a plurality of pulse transformers 50PT-150PT connected to a 25 Mbps ATM terminal.
-2, 50PT-3.

The function and configuration of the LEC bridge 7 will be described with reference to FIG. The LEC bridge 7 includes an Ethernet CPU 71 that interfaces with the Ethernet,
ROM 72, RAM 73, AAL5 controller 7
4, a 25 Mbps user network interface unit (ATM UNI) 75, a pulse transformer 76 as an interface with a branching device, an Ethernet transceiver 77 as a physical interface with Ethernet, for example, an AUI connector (10Base5) or an RJ45 modular jack. (10BaseT) and a pulse transformer 78 connected thereto.

The LEC bridge 7 connects the Ethernet to the AT
As means for connecting to the M branching device 5, an ARP function and an ARP table for converting an IP address into a MAC address are provided.

The LEC bridge 7 has an ATM signaling procedure (Q2931), a LE ARP procedure, and a unique control procedure. The LE ARP procedure has a unique procedure using a control cell with dedicated GFC / VP / VC assignment set at power-up. Further, the LEC bridge 7 is configured to support flow control of TCP / IP communication.

The GFC control protocol in the ATM-M bus system is defined as an M-GFC control protocol in this specification. The M-GFC control protocol is a bus control protocol realized by hardware (partially software) of the gateway 1 and the branching device 5. Preconditions for realizing the M-GFC flow control are shown below. The bus transmitted from the gateway 1 is a down bus, and the farthest end branching device 5
The bus that returns at −n and goes to the gateway 1 is called an up bus. The identifier ID of each branch device 5 is determined by an identifier automatic assignment process from the gateway 1 which is separately defined. In the transmission and reception of ATM cells on the bus by the branching device 5, the reception cells can be fetched only from the downstream bus, and the transmission cells can be set to either empty cells on the downstream bus or the upstream bus. However, if transmission is possible to both, transmission to the upstream bus is prioritized.

The gateway 1 has a branch device management table including an identification number (ID) correspondence table for each subordinate branch device. The gateway 1 monitors cells in the uplink bus, loops back cells whose transmission destination identification numbers are in the branching device management table, and sends out the cells to the downlink bus, thereby enabling communication in the M bus.

Here, GFC / VP / VC on the M bus will be described. CPU is each branch device, each terminal, WA
It has a dedicated control channel with N interfaces.
This dedicated control channel is a VC value and is distinguished from the VC during communication. That is, for cells using shared channels (5, 3, 4, etc.) for which the VC value has already been determined, the terminal device A is distinguished by VC1, the terminal device B by VC2, and the WAN interface by VC3. Also, the CPU 15
The AAL controller 151 and the AAL controller 196 of the WAN interface 19 have a function of setting a plurality of GFC / VP / VC of a cell to be taken.

The communication between terminal devices connected to the branch device in the M bus or the communication between the terminal device connected to the branch device and the terminal device connected to the WAN will be described below with reference to FIG. This will be described with reference to FIG. FIG. 7 is a diagram for explaining an outline of communication in the M bus.
5-2 is connected to the M bus 3, and the gateway 1 is connected to the WAN.
Shows a state where it is connected to.

In this communication system, the GFC / VP / VC of the cell between the terminal device accommodated in the branching device and the branching device and the GFC / VP / VC of the cell on the M bus are mutually converted by the branching device. GFC / VP of cell in gateway
/ VC and GFC / VP / VC of cells on the M bus are mutually converted by the gateway, so that communication between the terminal devices accommodated in the branch device without the intermediary of the exchange switch, or the device accommodated in the branch device This is a method that enables communication between a terminal device and a terminal device connected to a WAN.

(Cell Type Managed on M Bus) The cell type managed on the M bus is defined by GFC / VP / VC. Table 1 shows the contents of the definition.

[0058]

[Table 1]

The GFC of the cell flowing on the M bus carries the identification number of the branching device. On the down bus, it is determined as the identification number of the branching device that receives the cell. On the upstream bus, it is determined as the identification number of the branching device that transmitted the cell. The cell of GFC = "15" flowing on the M bus is a cell transmitted to all the branching devices and used for multicast. Cells with GFC = "0" flowing on the M bus are used as empty cells or SOS cells.

The port number of the branching device, that is, the number of the device under the branching device, is stored in the VP of the cell flowing on the M bus. And the type of the communication destination. For example, for VC, Hex, 0000 is an empty cell or reserved empty cell, Hex, 0003 is a segment-compatible OAM cell, and Hex, 0004 is an EE-compatible OAM.
A cell for AM, Hex, 0005 is a signaling cell, VC1 is a control cell with terminal A, VC2 is a control cell with terminal B, VC3 is a control cell with WAN interface, and VC is a communication cell. The VCs VC1 to VC3 for controlling the gateway CPU and each of the branching devices, the terminal devices, and the WAN interface are allocated at the time of initializing and at the time of layer 1 activation of the terminal device.
C is allocated in a call processing sequence described later. GFC / VP of a cell flowing between the terminal device and the branching device
Is composed of “0/0”.

As shown in Table 1, AT where GFC / VP / VC is set to "0/0/0"
The M cell is an empty cell, and the payloads are all “6A”.
The cell whose GFC / VP / VC is set to “0 / VPI / VCI” is an SOS cell from the branching device, and is made by setting the GFC of the data cell to “0”. A cell whose VP / VC is set to “ID / 0/0” is a reserved vacant cell in which the branching device is specified by the ID, and is transmitted from the gateway to the down bus GFC / VP / VC is set to “ID / VPI”. / VCI "is a transmission or reception data cell in which a branching device is specified by an ID. A cell whose GFC / VP / VC is" ID / VPI / VCI "is a cell having a multibus interface unit gateway. A control cell between branching devices, and a dedicated V
The PI / VCI value is used. Cells in which GFC / VP / VC is set to “15 / VPI / VCI” are multicast transmission and reception data cells from the branching device. GFC / VP / VC is "ID / 0/5 (Hex, 0
005) "is a transmission and reception point-point signaling cell in which the branching device is specified by the ID. The GFC / VP / VC is" ID / VPI / 3 (He
x, 0003) "is a dedicated cell at the time of failure, is a transmission or reception point-point correspondence VP OAM cell in which a branching device is specified by an ID, and corresponds to a segment. GFC / VP / VC is "ID / VPI / 4 (He
x, 0004) "is a dedicated cell at the time of failure, is a transmission or reception point-point VP OAM cell in which a branching device is specified by an ID, and corresponds to end-to-end.

(Gateway Protocol) Next, the gateway protocol will be described. Gateway 1
, A conversion table (ATC table) is formed.
This conversion table stores the GFC (I
D) GFC / which manages / VP / VC in the gateway
This is a table for mutually converting into VP / VC, and a table for converting GFC / VP / VC managed in the gateway into GFC (ID) / VP / VC of a call in communication on the bus. These routing tables store the maximum number of connections on the M bus (for example, 1024 channels),
It is managed based on data determined by the CU.

GFC indicates the ID of the branching device.
The ID of the branching device based on the GFC is used not only on the M bus 3 but also in the gateway to identify a cell to be transmitted to the down bus. Since 8 bits are allocated to VP, it is represented by Hex display (for example, 00). H
The lower 4 bits of ex display the terminal number under the branching device. Since 16 bits are allocated to VC, 0,
Expressing the shared channels 5, 5, and 4 in Hex display,
0000, 0005, 0003, 0004, respectively, and the data cell indicated by the CPU 15 in the call control is V
C, control cells are denoted by VC1 to VC3.

(Communication Sequence between Terminal Devices on M Bus) The branching device (ID = ID) accommodated in the M bus shown in FIG.
2) The terminal device A and the branch device (ID =
1) Signaling during communication of the terminal device B under the control of 5-1 will be described with reference to FIG. The terminal device A goes off-hook and GFC / VP / VC = 0/00/000
5 is transmitted to the branching device 5-2, the branching device 5-2 receives the GFC / V
It is converted to P / VC = 2/01/0005 and sent out onto the M bus 3.

In the gateway 1 which has detected this SET UP cell on the up bus of the M bus 3, the GFC / VP / V
The C conversion unit 14 refers to the ATC table and refers to the GFC / VP
/ VC = 0/00 / VC1 and sends it to the CPU 15.

The CPU 15 sets GFC / VP / VC = 0/00 / VC1 meaning that the SET UP has been accepted.
CALL PROCEEDING (hereinafter referred to as CALL PROC) cell is called GFC / VP /
Send to VC converter 14. CALL P from CPU 15
GFC / VP / VC converter 14 that has received the ROC cell
Is GFC / VP / VC = 2 by referring to the ATC table.
The data is converted into a CALL PROC cell of / 01/0005, transmitted to the down bus of the M bus 3, and transmitted to the branching device 5-2. The branching device 5-2 converts this CALL PROC cell into GFC / VP / VC = 0/00/0005 and transmits the terminal device A.

The CPU 15 of the gateway 1 also activates GFC / VP / VC = 0/00 to activate the destination terminal device.
/ VC2 is sent to the GFC / VP / VC converter 14. The GFC that received this SET UP cell
The / VP / VC conversion unit 14 refers to the ATC table and
S converted to GFC / VP / VC = 1/02/0005
The ET UP cell is transmitted to the branching device 5-1 via the down bus of the M bus 3, and the branching device 5-1 transmits the GFC / VP / VC
= 0/00/0005 and transmit to terminal device B.

Upon receiving the SET UP cell, the called terminal B performs a response operation (off-hook, etc.), and
Response of FC / VP / VC = 0/00/0005 (CON
NECT: "CONN") cell is returned to the branching device 5-1, and the branching device 5-1 sends the GFC / VP / VC
= 1/02/0005 to the gateway 1 via the up bus of the M bus 3.

When receiving the CONN cell from the branching device 5-1 on the upstream bus, the gateway 1 refers to the ATC table and sends the CONN cell converted to GFC / VP / VC = 0/00 / VC2 to the CPU 15. . CPU15
Is a response confirmation (CONNECTION ACKNOWREDGE: hereinafter referred to as CONN ACK) cell of GFC / VP / VC = 0/00 / VC2.
The C conversion unit 14 sends it.

The GFC / VP / VC conversion unit 14 uses an ATC
Referring to the table, GFC / VP / VC = 1/02 /
The CONN ACK cell converted to 0005 is transmitted on the up bus of the M bus 3.

The branching device 5-1 that has received the CONN ACK cell addressed to its own branching device is GFC / VP / VC = 0/0.
0/0005 and send it to terminal device B.
Shifts to the communication mode.

Further, the CPU 15 executes GFC / VP / V
The CONN cell of C = 0/00 / VC1 is replaced with GFC / VP /
Sends to the VC converter 14 and the GFC / VP / VC converter 14
Refers to the ATC table, and GFC / VP / VC =
The data is converted to 2/01/0005 and sent to the branching device 5-2 via the down bus of the M bus 3.

The branching device 5-2 receiving the CONN cell
Is converted to GFC / VP / VC = 0/00/0005 and transmitted to the terminal device A. The terminal device A
The CONN ACK cell of VC = 0/00/0005 is sent to the branching device 5-2, and the mode shifts to the communication mode. CON
The branching device 5-2 receiving the N ACK cell transmits the GFC /
CONN converted to VP / VC = 2/01/0005
The ACK cell is transmitted to the GFC / VP / VC converter 14 of the gateway 1.

The communication between the terminal devices A and B is established by this series of call processing sequences. In communication, a data cell of GFC / VP / VC = 0/00 / VC is sent from the terminal device A to the branching device 5-2, and the branching device 5-2.
Is converted to GFC / VP / VC = 2/01 / VC and sent to the gateway 1. GFC / V of Gateway 1
The P / VC converter 14 converts this data cell into a GFC / VP
/ VC = 1/02 / VC and transmits it to the branching device 5-1. The branching device 5-1 converts the GFC / VP / VC = 0/00.
/ VC and transmits to the terminal device B.

Similarly, the terminal device B sends GFC / VP / V
A data cell of C = 0/00 / VC is sent to the branching device 5-1 and the branching device 5-1 causes GFC / VP / VC = 1 /
02 / VC and sent to the gateway 1. The GFC / VP / VC conversion unit 14 of the gateway 1 converts the data cell into GFC / VP / VC = 2/01 / VC and transmits the data cell to the branching device 5-2.
C / VP / VC = 0/00 / VC and converted to terminal device A
Send to With this method, communication between the terminal device A and the terminal device B is executed. Here, VC during communication is C
This value is dynamically determined by the PU 15 in the call processing sequence.

In the above description, terminal device A and terminal device B
Has been described as being under the control of the different branching devices 5-2 and 5-1. However, the terminal device A and the terminal device B may each be under the control of the same branching device. Communication takes place.

(Communication sequence between terminal device on WAN and WAN terminal) Branch device (ID =
2) Signaling during communication between the terminal device A under 5-2 and the terminal device connected to the WAN will be described with reference to FIG. The terminal device A goes off-hook and the GFC /
When the SET UP cell of VP / VC = 0/00/0005 is transmitted to the branching device 5-2, the branching device 5-2 receives the GF
It is converted into a C / VP / VC = 2/01/0005 SET UP cell and sent out onto the M bus 3. This SET UP
Gateway 1 that detects a cell on the up bus of M bus 3
Is GFC / VP / VC = 0 with reference to the ATC table.
/ 00 / VC1 and converted to a SET UP cell
Send to 5.

CPU 15 receiving the SET UP cell
Is CALL of GFC / VP / VC = 0/00 / VC1
PROC cell and GFC / VP / VC = 0/00 / V
The G3C / VP / VC conversion unit 1 converts the C3 SET UP cell
4

Upon receiving the CALL PROC cell from the CPU 15, the GFC / VP / VC conversion unit 14 refers to the ATC table and converts the cell into GFC / VP / VC = 2 /
01/0005 CALL PROC cell,
Transmit on the down bus. Self-applied CALL PROC
The branching device 5-2 that has received the cell is GFC / VP / VC
= 0/0000/0005 and distributes it to the terminal device A.

The GFC / VP / VC converter 14 that has received the SET UPC cell from the CPU 15 converts this cell to A
GFC / VP / VC = 0/10 by referring to TC table
/ VC3 and sends it to the WAN interface 19.

The WAN interface 19 that has received the SET UP cell sends the SET UP cell to the other terminal device.
The P cell is transmitted via the WAN. This SET UP
When the destination terminal device that has called the cell responds, the CONN cell is transmitted to the WAN interface 19 via the WAN. The WAN interface 19 sets the GFC / VP / VC of the CONN cell received via the WAN to 0/1.
0 / VC3, and transfer it to the GFC / VP / VC converter 14.

GFC / VP receiving this CONN cell
/ VC conversion unit 14 refers to the ATC table and
The CONN cell converted to / VP / VC = 0/00 / VC3 is transferred to the CPU 15. Upon receiving the CONN cell, the CPU 15 executes GFC / VP / VC = 0/00 / VC
CONN cell converted to 1 and GFC / VP / VC = 0
/ 00 / VC3 CONN ACK cell to GFC / VP
/ VC conversion unit 14.

GFC / VP receiving this CONN cell
/ VC conversion unit 14 refers to the ATC table and
CONN converted to / VP / VC = 2/01/0005
The cell is transmitted to the branching device 5-2. The branching device 5-2 that has received the CONN cell generates GFC / VP / VC = 0 /
The data is converted into 00/0005 CONN cells and distributed to the terminal device 9A under the control. The terminal device 9A is a GFC / VP / V
The CONN ACK cell of C = 0/00/0005 is transmitted to the branching device 5-2, and the branching device 5-2 transmits the GFC / VP /
CONN ACK converted from VC to 2/01/0005
The cell is converted to the GFC / VP / VC converter 14 of the gateway 1
Send to

On the other hand, the GFC / VP / VC conversion unit 14
Upon receiving the CONN ACK cell from the CPU 15,
This cell is referred to the ATC table and GFC / VP / V
The data is converted into C = 0/10 // VC3 and transferred to the WAN interface 19. The WAN interface 19 sends out a CONN ACK cell for the partner terminal device via the WAN and notifies the partner terminal device. Through this series of call processing sequences, communication between the terminal device A accommodated in the branch device on the M bus and the terminal device accommodated in the -WAN is established.

Communication is performed from the terminal device A to the GFC / VP / V
A data cell of C = 0/00 / VC is sent to the branching device 5-2, and GFC / VP / VC = 2 /
01 / VC and sent to the gateway 1. The GFC / VP / VC conversion unit 14 of the gateway 1 converts the received data cell into GFC / VP / VC = 0/10 // VC
And sends it to the WAN interface 19, where W
The cell converted into a format adapted to the AN is sent to the partner terminal device via the WAN.

Similarly, the data cell sent from the partner terminal device via the WAN is converted by the WAN interface 19 into a data cell of GFC / VP / VC = 0/10 / VC, and the GFC / VP / VC conversion is performed. Sent to the unit 14. G
The FC / VP / VC converter 14 converts this data cell into a GF
Conversion to C / VP / VC = 2/01 / VC and branching device 5
-2.

The branching device 5-2 converts the received GFC / VP / VC of the cell addressed to itself into 0/00 / VC and distributes it to the terminal device under the branch. Here, VC during communication is shown in FIG.
In the same manner as described above, the value is dynamically determined by the CPU 15 in the call processing sequence. When FIG. 8 and FIG. 9 are established in the same time zone, the CPU 15 sets different values for VC in FIG. 8 and VC in FIG. Thus, the terminal device accommodated in the branch device on the M bus and the W
It is possible to communicate with a terminal device accommodated in the AN without passing through a higher-level switch (exchange device).

[0088]

According to the present invention, in the ATM-M bus system in which the end of the downstream bus is turned up to be the upstream bus, communication in the M bus can be performed without passing through the upper switch.

Further, according to the present invention, communication between the terminal device accommodated in the M bus and the WAN terminal can be performed without passing through a higher-level switch.

[Brief description of the drawings]

FIG. 1 is an AT to which a communication control method according to the present invention is applied
FIG. 1 is a block diagram showing a configuration of an MM bus system.

FIG. 2 is a block diagram showing a configuration of a gateway used in a communication control method of the ATM-M bus system according to the present invention.

FIG. 3 is a block diagram showing a configuration of a WAN interface circuit used in a communication control method of the ATM-M bus system according to the present invention.

FIG. 4 is a block diagram showing a configuration of a 155 Mbps branching device used in the communication control method of the ATM-M bus system according to the present invention.

FIG. 5 is a block diagram showing a configuration of a 25 Mbps branching device used in the communication control method of the ATM-M bus system according to the present invention.

FIG. 6 is a block diagram showing a configuration of an LEC bridge used in a communication control method of the ATM-M bus system according to the present invention.

FIG. 7 is a diagram for explaining a cell flow in the communication control method of the ATM-M bus system according to the present invention.

FIG. 8 is a communication sequence diagram on the M bus in the communication control method of the ATM-M bus system according to the present invention.

FIG. 9 is a communication sequence diagram between the M bus and the WAN in the communication control method for the ATM-M bus system according to the present invention.

FIG. 10 is a block diagram showing a configuration of an ATM-U bus system according to the prior application.

[Explanation of symbols]

Reference Signs List 1 gateway 11 cell control unit 111 M-GFC control unit 112 sequence control unit (multiplexer) 12 ATM user network interface unit 13 optical / electric conversion interface unit 14 GFC / VP / VC conversion unit (ATC) 15 CPU 16 ROM 17 RAM 18 AAL5 Controller 19 WAN Interface Circuit 191 CPU 192 ROM 193 RAM 194 INS64 Transceiver 195 Pulse Transformer 196 AAL Controller 20 SOS Change Table 3 M Bus 31 Folding Device 5 Branching Device 50 Optical / Electrical Conversion Interface 50PT Pulse Transformer 51 ATM User Network Interface Unit 52 Cell add / drop control unit (PLD), Cell add / drop distribution / assembly control unit 53 cells Fork insertion control section control ROM 54 F-ROM 55 RAM 56 CPU 57 LED display device 58 AC / DC converter 59 Reset circuit 7 LEC bridge 71 Ethernet CPU 72 ROM 73 RAM 74 AAL5 controller 75 ATM user network interface 76 Pulse transformer 77 Ethernet Transceiver 78 Ethernet interface pulse transformer 91 ATM telephone 92 ATM terminal 93 General-purpose terminal

Continuing on the front page (72) Inventor Hitoshi Hagiwara 24-4 Sakuragaoka-cho, Shibuya-ku, Tokyo Inside Nakayo Communication Aircraft Co., Ltd. (72) Inventor Junji Asakura 3-2-1-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Stocks In-company (72) Inventor Hitoshi Maeda 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation F-term (reference) 5K030 HA10 HB13 HB14 HB29 HC01 HD03 JT01 JT03 5K032 DA03 DA19 DB01 DB22 DB26 EC03

Claims (2)

[Claims] 1. An ATM comprising: a gateway; an M bus whose both ends are accommodated in the gateway and turned at the farthest end to be a down bus and an up bus; and a plurality of branching devices connected in series to the M bus. -In the communication method of the M bus system, the branching device uses the GFC / V used between the subordinate terminal device and the subordinate terminal device.
The gateway has a function of converting between P / VC and GFC / VP / VC used on the M bus, and the gateway converts the GFC / VP / VC of the cell transmitted on the downlink bus or the cell received on the uplink bus. , A function for mutually converting between GFC / VP / VC used on the M bus and GFC / VP / VC used in the gateway, and whether or not a cell received on the up bus is a communication on the M bus. An ATM having a function of judging, wherein when a cell received on the upstream bus is a communication on the M bus, the received cell is transmitted to the destination branching device via the downstream bus. -A communication control method for the M bus system. 2. A gateway, an M bus having both ends accommodated in the gateway and turned at the farthest end to form a down bus and an up bus, a plurality of branching devices connected in series to the M bus, and a gateway. A communication method for an ATM-M bus system comprising a WAN connected to a network, wherein the branching device uses a GFC / V
The gateway has a function of converting between P / VC and GFC / VP / VC used on the M bus, and the gateway converts the GFC / VP / VC of the cell transmitted on the downlink bus or the cell received on the uplink bus. , Function to convert between GFC / VP / VC used on the M bus and GFC / VP / VC used in the gateway, and determine whether the cell received on the upstream bus is for communication with WAN A communication control method for an ATM-M bus system, characterized in that when a cell received on an upstream bus is a communication with a WAN, the cell is transmitted to the WAN.