KR950006568B1 - Packet switching system of isdn switch - Google Patents

Abstract

The device improves the efficieny of packet processing and usefulness of connection and expansion. The device includes a digital subscriber matching unit (7) which has a 2B+D matching function, a primary subscriber matching unit(8) which has the 23B/30B+D matching function, a basic access multiple matching unit(9) which has the 8/12(2B+D) matching function, a frame multiple/anti-multiple unit(10) which has the frame multiple/anti-multiple unit function, the packet exchange unit(12) which has the packet data exchange function, a switch unit(11) which gives the packet data path, and a controller(13) which executes the control action. The device includes a packet processing menas(16), a packet assembly/ division means(17), a packet call control means(14), a the packet bus means(15).

Description

Packet Switching Device of ISDN Switching

1 is a schematic diagram illustrating the basic principle of a packet switched system.

2 is a block diagram of an ISDN switch having a packet switching function.

3 is a block diagram of a packet switching apparatus according to the present invention.

4 is a block diagram of a packet call control function block.

5 is a block diagram of a packet bus functional block.

6 is a block diagram of a packet processing function block.

7 is a block diagram of a packet assembly / decomposition function block.

* Explanation of symbols for the main parts of the drawings

14: packet call control function block 15: packet bus function block

16: packet processing function block 17: packet assembly / decomposition function block

The present invention relates to a packet switching apparatus for performing a packet service in an electronic exchange of the present invention.

Packet switching is one way to build a network that can adequately handle data congested in interactive computer traffic, where packets mean 'parcels'. In other words, when performing data communication, data is divided into a certain length, and the receiving side address and control information are added to each one to form one small parcel unit. That's the way.

An object of the present invention is to provide a packet switching apparatus that can be easily connected and expanded of the apparatus and improve the packet processing efficiency.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

1 is a diagram illustrating the basic principle of a packet switching equation. In the packet switching scheme, data is not directly transmitted between terminals as in a data communication system using a circuit switched network, which is one of a conventional leased line and a data circuit network. Data transmission method. That is, after the calling party exchanger 2 once stores the data information transmitted from the terminal 1 by the memory 1 as shown in FIG. 1a, the calling party exchange 2 and the called party exchanger as shown in FIG. 1b. (3) It transfers between the memories 5 and 6 of the switch 2 and 3 within a circuit network at high speed, and sends it to the destination terminal 4 as shown in FIG. 1C. Therefore, no transmission circuit for direct data transmission / reception is established between the terminals (1) and (4), and data information flowing in the circuit network is divided into predetermined lengths and divided into packet types with a header including a receiving address. And is transmitted by the exchanger 2 (3).

Considering the packet switching function in the ISDN, it was common for the early ISDN to coexist with the existing public packet switched data network, but now the packet switching function is included in the ISDN. Accordingly, the following factors should be considered as a review factor in constructing a packet switching system. These include the selection of a terminal protocol, a method of assembling and disassembling a packet, a method of realizing a virtual call exchange function, and a data packet transmission function. Method, matching method with existing packet network, response method and maintenance method of future broadband integrated information communication network.

In addition, as a requirement of packet switching function, it is as follows from the viewpoint of user, network operator and device provider. From the user's point of view, the terminal must be free to use circuit switching and B-channel packet-switched services, and the D-channel and B-channel packets must be able to communicate with computers and terminals joining the existing packet-switching network. Maintain a price equal to or below, and unify the tariff system. To this end, the packet-switching device in the electronic exchange shall be configured to provide CCITT X.25 protocol and packet assembly / disassembly function, matching function of CCITT X.75 protocol, and communication function of D-channel and B-channel packets. The network operator should be able to implement telephone exchange, data exchange and packet exchange as a single device, unify the maintenance of the device, and be able to integrate voice, data and packet in the transmission line. From the point of view of the device provider, the development of the circuit-switched device and the packet-switched device should be possible with the same resources, and the voice and packet switched services should be provided to the same device.

2 is a block diagram of an ISDN switch having a packet switching function, which is a digital subscriber matching device 7 having a 2B + D matching function, a primary group subscriber matching device 8 having a 25B / 30B + D matching function, and basic access. Access multiplexing matching device (9), digital subscriber matching device (7) and primary group matching device (8) and basic access multiplexing matching device (9) having multiplexed 8/12 × (2B + D) matching functions The D / D channel packet data from the frame multiplex / demultiplexer 10 having the frame multiplex / demultiplex function, the packet switching apparatus 12 having the exchange function of the B / D channel packet data, and the B / D channel packet data. And a switch device 11 which provides a passage for sending to the packet switching device 12, and a control device 13 which performs an operation control function of each device constituting the switch.

The ISDN exchange shall provide packet service to ISDN subscribers, interworking with ISDN, interworking with public packet switched data network, etc. In the packet switching system, the switch device 11 goes through a fixed-up path. Data is processed by layer 2 functions of each protocol and then organized into packets, and layer 3 functional data delivery functions are also processed, and also to provide packet services to character data terminal (C-DTE) subscribers in public telephone networks. Assembly / disassembly of the packets is performed.

That is, the B channel is transmitted to the packet switching device 12 through the switching device 11 by separating the B and D channels from the 2B + D signal and data information received from the ISDN subscriber through the digital subscriber matching device 7. The D-channel information transmits the packet data obtained by processing the layer 2 chromatocol to the packet switching device 12 through the frame multiplexing / demultiplexing device 10 and the switching device 11.

The primary group subscriber matching device 8 performs a function of separating the D channel from the 23B or 30B + D signal and data information received by the primary group matching, and the separated D channel information is further divided into signal and packet information. The double packet data is transmitted to the packet switching device 12 through the frame multiplexing / demultiplexing device 10 and the switching device 11.

The basic access multiplexing matching unit 9 processes data multiplexed by the basic access 2B + D, and separates the multiplexed channel and the D channel from the received 8/12 × (2B + D) signal and data information. Then, the separated D-channel information is divided into signal and packet information again, and the double packet data is transmitted to the packet switching apparatus 12 through the frame multiplexing / demultiplexing apparatus 10 and the switch apparatus 11.

The layer 1 and layer 2 functions of the D channel input from the ISDN digital subscriber are performed in the digital subscriber matching device 7, wherein the B channel and the D channel packet data are transmitted to the centrally configured packet switching device 12 in the case of a packet call. Send The packet exchange apparatus 12 analyzes the packet call, requests a number translation, and transmits packet data to the called party's electronic exchange, thereby establishing a packet call connection.

As such, the functions required for packet call processing in the ISDN exchange include Layer 3 functions related to packet call processing, Layer 2 functions for B channel packets, Layer 2 functions for D channel packets, and CCITT X.75 for interworking between ISDN. Layer 2 function for CCITT X.75 for interworking between public packet switched data network and analog transmission function, high speed channel providing function and packet assembly / disassembly function for interworking between packet switching devices 12 For example, the packet switching apparatus 12 should perform layer 2 and layer 3 functions such as CCITT X.25, X.75 and ISDN internal protocols, and have a function of assembling and disassembling packets.

3 is a block diagram of a packet switching apparatus 12 according to the present invention, including a packet processing function block 16 for processing a data transfer function among layer 2 and layer 3 functions for each packet-related cockle, and a public telephone network. Packet assembly / disassembly function block 17 which performs X.3, X.28, X.29 protocol processing function for subscriber, packet call which performs packet call processing procedure and maintenance function in packet switching device 12 A function of providing a communication path between the control function block 14, the packet call control function block 14, the packet processing function block 16, and the packet assembly / decomposition function block 17 in the packet switching device 12 is performed. It consists of a packet bus function block 15.

The packet call control function block 14 receives path information related to the packet call from the control device 13 and provides link establishment and release information to the packet processing function block 16 through the packet bus function block 15. Then, the charging information related to the packet call is requested from the packet processing function block 16, the result is collected and configured in a desired form, and then sent to the control device 13. The packet processing function block 16 accommodates a link connected to the switching device 11, and receives the control information from the packet call control function block 14 through the packet bus function block 15 between the calling party and the called party. Exchange packet data. The packet assembling / disassembly function block 17 accommodates a link connected to the switch device 11, and receives the control information from the packet call control function block 14 through the packet bus function block 15 to the subscribers of the public telephone network. Performs assembly and disassembly of packet data for data input from.

4 is a configuration diagram of the packet call control function block 14 according to the present invention, which communicates with the matching block 21 and the packet bus function block 15 of the control device in charge of the communication function with the control device 13. A packet bus matching block 22 in charge of the function, a link management function block 18 that performs a function related to setting and releasing a link connected to the packet processing function block 16, and checking and maintaining the link status; When establishing a virtual call, perform packet call processing procedures (X.25, IP, X.75) such as logical channel allocation and management functions for the corresponding call, and route data packet processing for packet data transmission for the logical channel. The virtual call control function block 19, which performs the function of transmitting to the function block 16, requests the packet processing function block 16 to collect the charging information related to the packet call, collects the result, and configures the result in a desired form. The packet collection function collects various necessary statistics data. It consists of a maintenance function block 20.

5 is a block diagram of the packet bus functional block 15 according to the present invention, which is connected to the packet call control function block 14, the packet processing function block 16, and the packet assembly / decomposition function block 17, so that The local bus arbitration function block for smooth communication between the local bus arbitration function block 24 and the function switching blocks in the packet switching device 12, which perform the arbitration function under the control of the central bus arbitration function block 23 so as to facilitate communication. And a central bus arbitration function block 23 which performs a total arbitration function using the information from (24).

6 is a block diagram of a packet processing function block 16 according to the present invention, in which a link connected to a packet bus matching block 25 and a switch device 11 in charge of a communication function with the packet bus function block 15 are provided. When data is transmitted after establishing a virtual call to a logical channel through a virtual call, the packet handling function block 14 does not go through the packet call control function block 14 with a route to the allocated logical channel. The link is connected to the packet data transfer function block 26 and the switch device 11 for transmitting data, generating charging data for the data transfer, and transmitting the data to the packet call control function block 14. According to the purpose, the link control function block 27 performs link control functions for B channel, D channel, public packet switched data network, and internal protocol according to packet data type. The link control function block 27 is a link control-B function block 28 which performs layer 2 function for the B channel packet, and the layer 2 function for the D-channel packet multiplexed by the packet multiplexing / demultiplexing device 10. A link control-D function block 29 to perform a link control-I function block 30 to perform an internal protocol (IP) of a packet protocol for interworking between co-exchange electronic exchanges and a layer 2 function of X.75, Link control-E function block 31, which performs high-speed channel processing for interconnection between packet-switching devices, and X.75 as a protocol when interworking with a public packet-switching data network. .75 layer control function and link control-P function block 32 for performing analytical packet data processing function when using an analog transmission method.

7 is a block diagram of a function block 17 for packet assembling / decomposing functions according to the present invention. The packet bus matching block 33 in charge of the communication function with the packet bus function block 15 and the C- of the public telephone network are shown in FIG. The speed conversion / multiplexing function block 36, in which the data generated from the DTE subscriber is multiplexed at the standard speed through the switch device 11 to convert and multiplex the input data at the original speed, the original speed Packet assembly function block 34, which performs a function of assembling the converted data into packet data, and a packet decomposition function block that performs packet data decomposition to transmit the received packet data at the same rate as that of a C-DTE subscriber. 35).

In order for each of the functional blocks of the packet switching device 12 to perform the packet processing function, the control device 13 requests the path connection to the switch device 11 for the path connection to the B channel packet call. After translating the destination address of the call request packet, the path related information is transmitted to the packet call control function block 14 according to the result, and the channel selection for the incoming signal of the packet switching device of the destination electronic exchange is requested. A function for requesting a link setting of the channel, a measurement of items related to traffic and performance for a packet call, a function of collecting charging information after performing call processing, and transmitting it to a corresponding function block, and in a packet processing function block 16 The status and maintenance functions of the link, the management function, and the state management functions such as the test, fault detection, and verification of the link performing packet call processing should be performed.

Referring to the packet call processing process using the packet-switching device 12 of the present invention. In the B-channel connection, the path from the calling party to the packet-switching device 12 is connected in the same way as the circuit-switched call by using the D-channel signaling method, and then the link-level connection is performed through the B-channel. Send a call request packet to the packet call control function block (14). The packet call control function block 14 transmits the destination address and origination address in the call request packet to the control device 13 to check the subscriber's status, class, and the like, and then requests a number translation for the corresponding B channel packet call. do. At this time, the setting management and release function of the logical channel for the packet call is performed by the packet call control function block 14, and the control device 13 requests the called party to the called party according to the number translation result.

Since the D-channel connection is composed of a fixed passage between the frame multiplexing / demultiplexing apparatus 10 and the packet switching apparatus 12, a portion described below is different from the B-channel connecting method. After the link level connection of the D channel is performed in the digital subscriber matching device 7, the call request packet of X.25 is transmitted to the packet call control function block 14 through the frame multiplexing / demultiplexing device 10. The packet call control function block 14 transmits the destination address and origination address in the call request packet to the control device 13 to check related matters such as the status and class of the subscriber, and then requests a number translation for the corresponding B channel packet call. do. At this time, the packet call control function block 14 performs the setting management and release function of the logical channel for the packet call, and the control device 13 knows the existence of the packet call through the D channel according to the number translation result and receives the call to the called party. This process is the same as the B channel connection.

The connection to the public packet switched data network establishes a path between the subscriber and the packet switching device 12 in the same manner as the B and D channel packet switching. If the number translation result is an incoming call to the public packet switched data network, the control device 13 connects the requested packet call through a fixed path to the packet switched data network. In the public packet switched data network, first, a link is established between the public packet switched data network and the packet processing function block 16 through a fixed path to receive a call request packet. Is the same as

In particular, in order to reduce the transmission delay when attempting to transmit data after setting up a call through these two connections, routing information about a logical channel established at the time of call establishment without passing through the packet call control function block 14 is transmitted. Managed at 26, the data is transmitted by exchanging data directly between the packet processing function blocks 16. FIG.

By configuring the packet-switching device 12 in this manner, it is easy to change and expand the device, and there is an advantage of maximizing packet processing efficiency.

Claims (6)

Digital subscriber matching device 7 with 2B + D matching function, primary group subscriber matching device 8 with 23B / 30B + D matching function, 8/12 × (2B + D) matching function multiplexed with basic access Basic access multiplexing matching device (9), frame multiplexing / demultiplexing device (10) having frame multiplexing / demultiplexing function of D-channel packet data, digital subscriber matching device having exchange function of B / D channel packet data (7) Frame multiplexing / demultiplexing apparatus 10 having frame multiplexing / demultiplexing function for D-channel packet data from primary group subscriber matching device 8, and packet switching apparatus 12 having a switching function of B / D channel packet data. ), A switch device 11 providing a passage for sending B / D channel packet data to the packet switching device 12, and a control device 13 performing an operation control function of each device constituting the switch. In the packet exchange apparatus of the configured ISDN switch, Packet processing function unit 16 for processing data transfer function among layer 2 function and layer 3 function for protocol, packet assembly performing X.3, X.28, X.29 protocol processing function for public telephone network subscriber / Decomposition function means 17, packet call control function means 14 for performing packet call processing procedures and maintenance functions in the packet switching device 12, and the packet call control function means 14 in the packet switch 12. And a packet bus function means (15) for providing a communication path between the packet processing function means (16) and the packet assembly / decomposition function means (17). 2. The packet call control function means (14) according to claim 1, wherein the packet call control function means (14) is configured to control the communication function with the control device matching means (21) and the packet bus function means (15) in charge of the communication function with the control device (13). The link management function means 18 which performs the functions related to the setting and releasing function of the link connected to the packet bus matching means 22, the packet processing function means 16, the state inspection and maintenance of the link, and the virtual call When setting, it performs packet call processing procedure (X.25, IP, X.75, etc.) such as logical channel allocation and management function for the corresponding call, and packet processing function for route data for packet data transmission for the logical channel. A virtual call control function means 19 which performs the function of transmitting to the means 16, requests the packet processing function means 16 to collect the charging information related to the packet call, collects the result and configures it in a desired form, Performing the function of collecting various necessary statistical data And a packet maintenance function means (20). The apparatus of claim 1, wherein the packet bus functional means (15) is connected to the packet call control functional means (14), the packet processing functional means (16), and the packet assembly / disassembly functional means (17) so that they can communicate smoothly. The local bus arbitration function means 24, which performs the arbitration function under the control of the central bus arbitration function means 23, and the local bus arbitration function means for smooth communication between the respective functional blocks in the packet switching device 12. 24. A packet exchange apparatus comprising a central bus arbitration function means for performing an overall arbitration function using information from 24). 2. The packet processing function means (16) according to claim 1, wherein the packet processing function means (16) connects a packet bus matching means (25) which is in charge of a communication function with the packet bus function means (15) and a link connected to the switch device (11). When data is to be transmitted after establishing a virtual call to a logical channel through the packet processing function means 16 without routing the packet call control function means 14 with routing information on the logical channel allocated when the virtual call is established. Packet data transfer function means 26 and switch device 11 for transmitting data to a desired link between the channels and generating charge data for data transmission and transmitting the data to the packet call control function means 14. And a link control function means 27 which performs link control functions for B channel, D channel, public packet switched data network and internal protocol for each packet data type according to the purpose of use. Packet switching device, characterized in that. The packet assembly / disassembly function unit (17) according to claim 1, wherein the packet assembly / disassembly function unit (17) is generated from a packet bus matching unit (33) in charge of a communication function with the packet bus function unit (15), and a C-DTE subscriber of a public telephone network. The converted data is multiplexed at the standard speed through the switch device 11, and the speed converting / multiplexing function means 36 performs a function of converting and multiplexing the input data at the original speed, and the data converted at the original speed. Packet assembly function means 34 for assembling the packet data into packet data, and packet decomposition function means 35 for performing packet data decomposition function to transmit the received packet data at the same rate as the C-DTE subscriber. A method for constructing a packet switching apparatus of an electronic exchange. 5. The packet multiplexing device according to claim 4, wherein the link control function means (27) includes: link control-B function means (28) for performing layer 2 functions on B-channel packets, and packet multiplexing in the frame multiplexing / demultiplexing apparatus (10). Link control-D function means 29 for performing layer 2 function on the D-channel packet, and link control for performing layer 2 function of X.75 and packet protocol internal protocol (IP) for interworking between co-exchange electronic exchanges. -I functional means 30, link control-E functional means 31 for performing high-speed channel processing for interconnection between packet switching apparatuses when a packet switching apparatus is added, and a protocol for interworking with a public packet switched data network. And a link control-P function means (32) for performing an analog packet data processing function when using an X.75 layer 2 function and an analog transmission method using X.75.