A retransmission mechanism for ISDN user-network interface data link layer

Abstract

The utility model discloses a retransmission mechanism of a data link layer between ISDN users and network interface, belonging to the technical field of network communication. The method stores sending frames through an array; the subscript of the array is corresponding to the sending sequence number of the frames; therefore, when the receiver requires the sender to retransmit, the information frame can be directly found in the array according to the sequence number expected from the receiver to retransmit. Compared with the prior art, the utility model has the advantages of simple and reliable method and improves the implementation efficiency and reliability of the system.

Description

technical field [0001] The invention belongs to the technical scope of network communication, and in particular relates to a retransmission mechanism of ISDN user-network interface data link layer. Background technique [0002] In the telephone exchange using the ISDN protocol, in order to make the ISDN protocol communication stable and reliable, retransmission must be used for the lost data during the communication process to ensure that the receiver completely receives the data sent by the sender. [0003] The national standard of the ISDN user-network interface data link layer imposes some restrictions on the structure, operation variables and serial number values ​​of the information frame of the communication. [0004] It is stipulated that each information frame is numbered sequentially, and the number value is cycled from 0-127. [0005] Sending state variable V(s): V(s) indicates the serial number of the next information frame to be sent in order, V(s) can take any ...

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Problems solved by technology

[0016] In view of the method that prior art switch software adopts when processing retransmission is to open up a capacity and be that the message frame that 7 letters send is also stored in this queue, after confirming once, the confirmed message frame is removed from this queue, need When retransmitting, search the queue according to the expected sending sequence number N(S) value and then retransmit. This kind of processing is cumbersome for the management and operation of the retransmission queue with a capacity of 7. One item needs to be cleared every time it is confirmed. When retransmitting, it must be searched from the queue

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