JPH03104344A - Plural channel communication system - Google Patents

Abstract

PURPOSE:To send an information string to plural transmission lines while being dispersed by adding a serial number representing the transmission order of a series of cells to a header of each cell and decoding the information string from a received virtual channel identifier and the serial number. CONSTITUTION:The connection is set between a caller terminal equipment P and a called terminal equipment Q and the information is sent by using cells whose virtual channel identifier (VCI) is '1' and '2' respectively. A self-routing pattern in an exchange is set so that exchanges A, B are connected via an inter-network cell transfer route RT1 when the VCI is '1', and via an inter- network cell transfer route RT2 when the VCI is '2'. An information string generated in an information generating section PS is processed into a cell by an information cell processing section PT and sent to a subscriber transmission line (a). The information string decoding section QT decodes the cell received from a subscriber transmission line (f) into an information string and sent to the information reception section QS.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multi-channel communication system, and in particular to a communication system that requires a transmission path using an ATM and an exchange having a function of self-routing cells in units of information transfer. Related to multiple channel communication systems for networks.

[Conventional technology]

The communication system of the communication network, which consists of a transmission line using a conventional ATM and a switch that has a function of self-routing cells in units of information transfer, uses a virtual channel identifier (hereinafter referred to as VC) in response to one connection request. A cell with the same VCI is generated and transmitted from the originating terminal according to the information string, and the information is transmitted to the destination terminal via a route determined for each VCI in the communication network. The method was to be transferred.

[Problem to be solved by the invention]

In the communication method of the conventional communication network described above, in response to one connection request, a route is generally set semi-fixed for each VCI from the start to the end of the connection. Since other terminal-to-terminal connections are also multiplexed on the same transmission path, if the amount of information generated from the originating terminal is large or the amount of information generated varies significantly, the amount of information generated by the other terminal-to-terminal connections may be reduced. There has been a problem in that the fluctuations and the fluctuations in the amount of information generated by itself interact with each other, making it easy for connection quality to deteriorate.

An object of the present invention is to set a cell transfer route differently for each virtual channel identifier in a communication network from a source terminal to a destination terminal, and to set a sequence number indicating the transmission order of a series of cells. By adding this to the cell header and restoring the information string from the received virtual channel identifier and sequence number, the information string to be sent can be distributed over multiple transmission paths and the amount of information transferred per route can be reduced. In addition, by creating multiple cell routes, cells are not discarded due to deterioration in connection quality. The object of the present invention is to provide a multi-channel communication method that can reduce the risk of

[Means to solve the problem]

In the multi-channel communication system of the present invention, within a communication network consisting of a transmission line using ATM and an exchange having a function of self-routing cells in units of information transfer, an originating exchange receives a connection setup request signal from an originating terminal. an assignment function that assigns multiple virtual channel identifiers to this connection setting request;
and a route selection function that sets a transmission route for the cell to be different for each of the virtual channel identifiers, and the destination exchange collects the cells arriving via a plurality of different routes. By providing a cell aggregation function that transfers the cells to the destination terminal, connections between the originating and terminating terminals are made using multiple routes, and the originating terminal transmits the generated information to the originating side when the connection setting request signal is exited. The plurality of virtual channel identifiers assigned by the exchange are sequentially added to the cell header, and at the same time, a sequence number indicating the sending order of a series of cells for each virtual channel identifier is also added to the header information, and the cells are sent to the transmission path. The terminating terminal restores the information string from the series of cells sent from the originating terminal based on the plurality of virtual channel identifiers and sequence numbers in the header of the cells sent from the terminating exchange. It is.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram for explaining multi-channel communication according to an embodiment of the present invention.

P is an originating terminal, Q is a terminating terminal, A, B, C, and D are exchanges having a cell switching function using a self-routing function. In this embodiment, A is an originating exchange and B is a terminating exchange. a,
b, c, d, e, and f are transmission lines using ATM, and of these, a and f are subscriber line transmission lines that connect the originating terminal and the originating exchange, and the terminating terminal and the terminating exchange, respectively. b
, c, d, and e are relay transmission lines, respectively.

In this embodiment, a connection is set up between the originating terminal P and the terminating terminal Q, and information transfer is performed using cells with VC■ values of "1" and "2", but VCI is "1". In this case, AB is transferred via intra-network cell transfer route RT1.
If the VCI is "2", the self-routing pattern in the network exchanges is set so that exchanges A and B are connected via the intra-network cell transfer route}-RT2 route. ing.

FIG. 2 is a block diagram showing an example of the configuration of the originating terminal P.

PS is an information generating section, and the information string generated here is sent to the information cell forming section PT via the terminal internal transmission path pv. The information cell converting section PT converts the information string into cells and sends them to the subscriber line transmission line a.

FIG. 3 is a block diagram showing an example of the configuration of the destination terminal Q. The information string restoring section QT restores the cells received from the subscriber transmission path f into an information string, and sends it to the information receiving section QS via the terminal internal transmission path qv.

FIG. 4 is a data pattern diagram at each point in information transfer between the originating terminal P and the terminating terminal Q.

The information string generated from the information generation part ps of the originating terminal P becomes a continuous information string at any point (hereinafter referred to as pv point) in the terminal internal transmission path pv, as shown in FIG. 4 (1). In this case, the data is stored in the information cell conversion unit PT in the order of b1 byte, b2 byte, b3 byte, etc.
It will be sent towards. In addition, the ver values used for the connection between the originating terminal P and the terminating terminal Q are "1" and "2".
It is assumed that the originating exchange A has assigned the use of two types of VC■. The cell in this example is
VCI to information part I NFO carrying 4 bytes of information
It is assumed that the format is such that the sequence number SEQ is added as a header. The information cell generator PT divides the received information string into 4-byte units, alternately adds ``rl'' or ``2'' as the VCI, adds a sequence number to each VCI value, and sends it to the subscriber line transmission line a. Send in cell form.

Figure 4 (2) shows the state of data passing through an arbitrary point (hereinafter referred to as point a) in subscriber line transmission line a.
Cells with VCI=1 are sent every other cell starting from the first cell, and the order number SEQ of these cells is 0.1·
..., and cells of VCI2 are sent out every other cell starting from the second cell, and the sequence number SEQ of these cells is 0.1... .

The sent cells reach the exchange A via the subscriber line transmission line 3, where connection routes are assigned according to the VCI. ver-i cell is intra-network cell transfer route RTI
, the cell with VCI=2 is an intra-network cell transfer route}RT
It is transferred to exchange B via route 2. Multiple other connections are multiplexed on the transmission lines on the intra-network cell transfer routes RTI and RT2 to transfer cells, and depending on the traffic condition of each route and the difference in distance, the connection between exchanges A and B may be different. Since the cell transfer times are different, the order of cells sent from exchange B to destination terminal Q through subscriber transmission path f may differ from the order of cells sent from originating terminal P.

In such a case, any point below f in the subscriber transmission path f
The fourth figure shows the state of the data passing through the point.
Figure (3) shows an example in which the order of arrival of cells is reversed.

The information string restoring unit QT in the destination terminal Q
Looking at r and sequence number SEQ, VCI=1SEQ=O, VC
I=2・SEQ=O. VCI=1・SEQ=l, VCI
=2・SEQ=1・・・・・・・V
For the CI value, "1" and "2" are taken out alternately, and for the sequence number SEQ, cells are taken out in ascending order and sent to the terminal internal transmission path qv as an information string.

FIG. 4 (4) shows the information string sent from the information string restoring unit QT passing through an arbitrary point (hereinafter referred to as qv point) in the terminal internal transmission path qv, and the information generating unit of the originating terminal P. A continuous information string identical to the information string generated from ps is obtained and sent to the information receiving section QS. Figure 5 shows VC within the communication network.
FIG. 4 is a data pattern diagram at each point in information transfer between the originating terminal P and the terminating terminal Q for explaining a case where a cell with I=2-SEQ=O is lost; FIG. Figure 5 (1) and (
Regarding 2), it is the same as Figure 4 (1) and (2>), but Figure 5 (3) shows what happens when a cell with VCI = 2 and SEQ = O is lost in the communication network. In this case, the information string restoring unit QT sends byte positions b5 to b8 that should be included in the lost cell as dummy bytes X.

〔Effect of the invention〕

As explained above, in the present invention, an originating exchange receives a connection setup request signal from an originating terminal in a communication network that includes a transmission path using ATM and an exchange having a function of self-routing cells in units of information transfer. has an allocation function that allocates multiple virtual channel identifiers to this connection setting request, and a route selection function that sets a cell transfer route so that the transmission route to the destination terminal is different for each virtual channel identifier, The destination exchange is equipped with a cell aggregation function that collects cells that arrive via multiple different routes and transfers the cells to the destination terminal, thereby connecting the originating and terminating terminals using multiple routes. When the connection setup request signal is sent, the multiple virtual channel identifiers assigned by the originating exchange are sequentially added to the cell header, and at the same time, a sequence number indicating the sending order of a series of cells for each virtual channel identifier is also added to the header information. The destination terminal restores an information string from a series of cells sent from the originating terminal based on the multiple virtual channel identifiers and sequence numbers in the cell header sent from the destination exchange. This makes it possible to reduce the amount of information transferred per route by distributing the information string to be transmitted over multiple transmission paths, and to reduce the amount of information transferred between other terminals on a transmission path where connections between other terminals are multiplexed. In addition, by creating multiple cell routes, it is possible to reduce the risk of cell discard due to deterioration in connection quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining multi-channel communication according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of the configuration of the originating terminal P, and FIG. 3 is an example of the configuration of the destination terminal Q. 4 is a data pattern diagram at each point in information transfer between the originating terminal P and the terminating terminal Q, and FIG. It is a data pattern diagram at each point in information transfer between terminal P and destination terminal Q. A, B, C, D... Exchange, INFO...
・・Information department, P・・・・・・ Originating terminal, PS・・・・・・
Information generation department, PT... Information cellization department, Q...
... Destination terminal, QS ... Information receiving section, QT ...
...Information sequence restoration unit, RTI, RT2...--Network cell transfer route, SEQ...Sequence number, VC
I...Virtual channel identifier, a, f...
- Subscriber line transmission line, b, c, d, e...Relay transmission line, pv. qv...Terminal internal transmission path.

Claims (1)

[Claims] Receives a connection setup request signal from a calling terminal within a communication network consisting of a transmission path using ATM and an exchange that converts information strings into a set of cells that are multiple information transfer units and has the function of self-routing these cells. The originating exchange has an assignment function that allocates multiple virtual channel identifiers in response to this connection setup request, and a route selection function that sets the cell transfer route so that the transmission route to the destination terminal is different for each virtual channel identifier. The terminating exchange has a cell aggregation function that converges the cells arriving via different routes and transfers the cells to the terminating terminal, thereby connecting the originating and terminating terminals using multiple routes. A multi-channel communication method characterized by: