Method for hybrid transmission of variable-length data packet and fixed length cell, and adaptation device

Abstract

This invention discloses a method and an adaptive device for hybrid- transferring variable-length data packets and fixed size cells. The method and the device finish the images between the packet and the UFPDU, the fixed size cell and the rectified asynchronous transition mode (ATM) cell. The UFPDU and rectified ATM cell are transferred on a same VC / VT or a bare fiber / cable of SDH / SONET after processed by mix or separation, rate adaptation, penetrability conversion, scrambling or de-scrambling, image or fetch. The mark of UFPDU is compatible with that of the ATM, connection or connectionless ways are applied for the variable length data packet transfer.

Description

Technical field: [0001] The invention relates to related data transmission in information network. In particular, it involves mixed transmission of variable-length data packets and fixed-length cells on the same virtual container / virtual branch VC / VT or bare optical fiber / cable of the synchronous digital system / synchronous optical network SDH / SONET transmission line. The PDU method and adaptation device can provide packet transmission interfaces for relevant information network equipment, such as asynchronous transfer mode ATM interface and Ethernet medium independent interface MII. Background technique: [0002] In various transmission systems and information networks, network endpoints use synchronous digital system / synchronous optical network SDH / SONET equipment to complete the transmission of variable-length packets or asynchronous transfer mode ATM cells. Variable-length data packets (Internet Protocol IP packets, Ethernet media access control MAC frames, etc.) are enc...

AI Technical Summary

Problems solved by technology

[0007] (3) There is no clear mention of how to distinguish between the two protocol data units (PDUs) when mixed transmission of variable-length packets and ATM cells in asynchronous transfer mode;

[0008] (4) FAST does not provide a connectionless data transmission function similar to the Internet Protocol IP network;

[0009] (5) When the high-level data packet is long, FAST divides it into multiple FAST frames for transmission, but the sequence number and position of the packet will occupy 3 bytes of overhead, which is relatively large;

[0010] (6) The load priority (such as the priority of high-level data user services) is not provided in the protocol data unit PDU of FAST, so that the network forwarding node working in the connectionless mode cannot provide different services such as language / video and data. Forwarding and switching strategies cannot guarantee the quality of service (QoS) of real-time user services

The disadvantages of this scheme are: (1) variable-length packets and fixed-length packets adopt different encapsulations, which increases the complexity of the implementation of related transmission and switching equipment; (2) because switching equipment uses virtual channel identifiers / virtual path Symbol VPI / VCI realizes cell switching, and the use of advanced data link control HDLC frame can only realize point-to-point transmission, and it is impossible to use a switching unit to complete variable-length packet and fixed-length packet switching; (3) because n is variable, The multiframe structure is complex, and the end-to-end transmission delay of ATM cells in asynchronous transfer mode is increased

Images