JPS61113343A - Exchange system - Google Patents

Abstract

PURPOSE:To improve the increase of exchange processing capability and connection service by connecting directly a local exchange ladder to a main switch via a relay terminal station device in an exchange system where a high speed switch as the main switch is controlled by a central controller. CONSTITUTION:The high speed main switch 12 controlled by the central controller 11 accommodates and connects the relay terminal station device 22 connected to a ring form link 21 and a terminal connector 32 connecting a high speed terminal device 31. The ring form link 21 forms the local exchange ladder by connecting the device 22 and plural terminal station devices 24 accommodating and connecting the terminal device 23 in tandem. The token link system is applied to the transmission control means in the link 21 and the transmission control procedure by the packet exchange service is applied to the devices 22 and 24. The connection from a terminal A to a terminal B in the same device 24 is processed by the device 24 and the call from the terminal A to a terminal C over the device 24 in the link 21 is processed by the device 24 via the link 21. The outgoing/incoming call in the local exchange ladder is processed by the device 22 and the call is connected to the destination via the main switch 12 under the control of the device 11.

Description

[Detailed Description of the Invention] (Industrial Application Field) A switching system in which a terminal device or a switch is connected to a high-speed transmission communication line, and these communication lines are exchanged and connected using a high-speed switch, and in particular, a ring link is used as a local exchange ladder. Regarding the exchange method.

(Prior Art) In the conventional switching system, when a terminal device hierarchy is provided in which terminal devices are directly connected by a ring link, a synchronization method is used in which the position corresponding to each terminal device is set in advance in one frame transmitted to the ring link. A central control unit that controls the main switch synchronizes and controls the frames transmitted on the ring link.

On the other hand, local area communication networks (such as L
One of the ANs is formed by connecting a plurality of terminal devices with a ring link. This local area communication network requires the addition of another local area communication network as the amount of communication within the network increases, and communication between each local area communication network is connected as a relay call via another communication network such as a public communication network. Process.

(Problems to be Solved by the Invention) As mentioned above, in the conventional switching system, the central control unit is configured to control the terminal devices directly connected via a ring link, so the scale is limited due to the processing capacity of the central control unit. is limited. On the other hand, local area communication networks that connect terminal devices with ring links form an independent switching system, so communication between communication networks is processed as a relay call via another communication network, and therefore connection services are limited. This will inevitably lead to a deterioration in economic efficiency.

(Means for Solving the Problems) The switching system according to the present invention includes a switching system in which a high-speed switch as a main switch is controlled by a central controller, and a local switching ladder that connects directly to the main switch via a relay terminal device. . This local switching ladder consists of a terminal terminal device that accommodates and connects at least a terminal device, a relay terminal device that connects to the main switch, and connects these terminal devices in a skewer, applying a token ring transmission control procedure. An annular link. The relay terminal equipment interconnects with the central controller in terms of relay calls. The switching system also has a transmission control means using a packet switching service for information transfer within the system from the local switching layer through the main switch.

Therefore, communication between terminal equipment within one local exchange ladder does not place a load on the central control unit, and communication between local exchange stairs can be efficiently handled within one exchange system.

(Example) Next, the exchange system of the present invention will be described by way of an example with reference to the drawings.

FIG. 1 is a functional block diagram showing one embodiment of the present invention. As shown in FIG. 1, a main switch 12 controlled by a central control device 11 accommodates and connects a relay terminal device 22 coupled to an annular link 21 and a terminal connection device 32 that connects a high-speed terminal device 31. The annular link 21 connects a plurality of terminal terminal devices 24 accommodating and connecting a relay terminal device 22 and a plurality of terminal devices 23 in a skewered manner to form a local exchange ladder. A call from the terminal device 23 is sent to the terminal terminal device 24.
, and the connection from terminal device A to terminal device B within the same terminal device 24 is processed by the terminal device 24 . Calls across the terminal equipment 24 in the local exchange hierarchy, ie, calls from the terminal equipment iA to the terminal equipment C, are handled by the terminal equipment 24 via the circular link 21. Further, incoming and outgoing calls on the local exchange ladder are processed by the relay terminal device 22, which receives the control of the central control device 11 and connects to the other party via the main switch 12.

A local switching ladder with a ring link 21 does not have a common control device, and terminal equipment (22° 24) connected in series sends a token (permit to transmit an information packet) to the ring link 2.
1, the data to be transmitted is sent out.

Next, the transmission control procedure in the ring link 21 will be explained with reference to FIG. ■ in Figure 2 is CCITTX, 25
The relationship and structure between frames and packets in the second
■ in the figure shows an example of the frame structure applied to the present invention, ■ in FIG. FIG. 3 is a configuration diagram showing information included in a packet (hereinafter referred to as DT).

In Figure 2, one frame is CCITTX,
To 25! 7 frame sequence (F) part addressed to 08 bits,
The address (A) part, the control (C) part, the information within 2080 pits (INF) part, the 16-bit frame check sequence (Fe2) part, and the 8-bit frame sequence CF) part are transmitted in this order. In the embodiment shown in (■) in FIG. 2, the address part of the transmission frame has 8 bits each for the frame destination address DFA and the frame source address SFA, and also for the INF forming the packet.
8 bits of the line number LN set for each communication are added to the section.

The packet name used in the connection control procedure shown in Figure 2 is the packet type identifier (TYP).
) is shown in 8 bits. Only the call request (CR) packet uses the 32 bits of the called destination address (DA) and the 32 bits of the calling source address (SA), which are the addresses of both the calling and receiving terminal equipment (DTE), in order to set up a data transfer channel. include. Since the DT packet marked @ in FIG. 2 passes through the link established by the CR packet, the packets each have 1 bit of a bucket type identifier (TYP) indicating the DT packet and 1 bit of the more data display example.

The transmission sequence number p(s
) and a receiving order number P (R).

The frame destination address DFA and set line number LN shown in ■ in FIG. Set. Frames transmitted on the ring link provide packet switching services in an asynchronous manner, and therefore cannot form a specific circuit. Therefore, a set line number LN is assigned to each packet as the line through which the packet is transmitted.

Next, the relay terminal device shown in FIG. 1 will be explained with reference to the drawings. Terminal devices including terminal terminal devices also have similar functions.

FIGS. 3 and 4 are a functional block diagram and a flowchart showing one embodiment of the main operating procedures of the relay terminal device.

According to FIG. 3, the relay terminal device includes a transmission frame receiving means 101 that receives a transmission frame from the ring link 21, a received frame importing means 102 that identifies the frame destination address DFA and imports the received frame, and token identification means 103 for identifying a token from a received frame;
Outgoing packet information memory 04 stores information to be transmitted via the main switch 12;
2, packet information receiving means 111 that receives packet information from the main switch 12, incoming packet information memory 12 that stores incoming packets received via the main switch 2, Packet information extracting means 113 that sequentially extracts packet information from the incoming packet information memory 12; transmission frame transmitting means 114 that forms the extracted packet information into a frame and transmits it to the circular link 21; and information is sent from the packet information extracting means 113. end of
. ).

A token code forming means 115 is provided for receiving the notification and forming and outputting a token code. The outgoing packet information memory 04 stores packet information INF in areas corresponding to the frame source address SFA and the set line number LN.

The incoming packet information memory 112 stores packet information INF in areas corresponding to the frame destination address DFA and the set line number LN.

Next, the operating procedure of the relay terminal device will be explained with reference to FIG. 4 and FIGS. 1 to 3 together.

When the relay terminal device 22 receives a transmission frame via the ring link 21 (operation procedure 1), it identifies the destination (terminal device) address of the received transmission frame and detects its own terminal device address. The frame is taken in as a received frame (operation procedure 2), and a predetermined token code is identified from the control unit of the received received frame (operation procedure 3).

If the code is not a token code, the relay terminal device stores packet information in the source address corresponding area for each set line number of the received frame (operation step 4). Next, the central controller that controls the main switch sequentially retrieves the set line numbers of the stored packet information (operation step 5), and receives a notification from the central controller that the connection operation of the main switch according to the set line number is completed ( Operator 116). In response to the operation completion notification from the main switch, packet information corresponding to the set line number is transmitted to the main switch (operation step 7). On the other hand, when receiving information via the main switch, the relay terminal equipment first receives the set line number from the central controller and, if necessary, the Peke frame destination (terminal equipment) address or the called destination (terminal equipment). The address is received (operation procedure 11), and packet information is received via the link of the connected main switch (@operation procedure 12). The relay terminal device stores the received packet information for each set line number (operation step 13). If the frame destination address is not transmitted from the central control unit, it is determined from the final call destination address DA included as information when a call request (CR) packet is received and is stored (operation step 14). Here, the relay station device waits for the token to be received via the circular link, and when the token is received, the relay terminal device extracts the stored packet information such as the frame destination address (operation step 15), and forms a transmission frame. Transmit (operation step 16). When all of the transmission information has been sent, the token code is extracted, formed into a frame, and transmitted to the ring link (operation step 17) in order to transfer the token to the next terminal device in the order.

In this embodiment, the central control unit sets and stores the numbers and positions of the frame destination ATVS and the relay terminal equipment on each side of the main switch, corresponding to the set line number, in accordance with the call request, and transmits the packet. Although the explanation has been given in which the main switch is operated each time the call is taken out, a conventional packet switching service can be implemented in which the main switch sets up one line for one communication call from the call request to the call disconnection.

Further, when packet transmission is adopted from the terminal device through the local switching ladder, there is no need to convert data information, so transmission efficiency is improved. In this way, it is not possible to unify the transmission control procedure within the switching system using one packet switching service, or to apply the packet switching service only within the ring link and have the main switch hierarchy follow a different transmission control procedure. The effects of the present invention can be exhibited.

In this embodiment, only the local exchange ladder and high-speed terminal equipment using a ring link are connected to the main switch in Figure 1. However, as with the normal switching system, any type of line can be connected to the terminal equipment for interconnection. Can be accommodated and connected via. Furthermore, in the above description of the operation, the functional block means in FIG. 3 was expressed as an operation because the microconbeater can perform the functional operation by utilizing the stored programs and data when it is implemented as hardware. When the functional block means is implemented as hardware, parallel operation is possible.

(Effects of the Invention) As explained above, in the switching system of the present invention, the central controller controls only the main switch, which is a high-speed switch that mainly handles relay calls, and has a central control system using the main switch and the token ring system. By connecting the local switching ladder that forms a circular link using a relay terminal equipment and transmitting information from the terminal equipment that accommodates at least the terminal equipment, it is possible to The benefits include increased processing capacity, improved connectivity services, and improved economic efficiency.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the switching system of the present invention, and FIG. 2 is a diagram showing an example of the transmission control procedure of the present invention. In the figure, ■ indicates CCI TTX. 25 is a frame configuration diagram recommended in 25, ■ is a frame configuration diagram showing an example applied to the present invention, ■, @ is information IN which is a packet
A packet configuration diagram showing a part of the structure of a packet and a DT packet used in the connection control procedure of the F part, and FIGS. 3 and 4 show an example of the main operation procedure of the relay terminal equipment in FIG. 1. 2 is a functional block diagram and a flowchart. 11...Central control unit, 12...Main switch, 21...Annular link, 22...
・Relay terminal equipment, 23 Fig. 1

Claims (1)

[Claims] In an exchange system in which a high-speed switch is used as the main switch and is controlled by a central control unit, there are terminal terminal equipment that mainly accommodates and connects terminal equipment, relay terminal equipment that directly accommodates and connects to the main switch, and these terminal equipment and relays. At least one ring link connects terminal equipment in series and applies a transmission control procedure based on the token ring method as a local switching ladder, and the terminal equipment and the relay terminal equipment perform transmission using a packet switching service. An exchange system characterized by having means for transferring information by applying a control procedure.