【資料名稱】：ITU-T Q703

【資料作者】：ITU-T

【資料日期】：未知

【資料語(yǔ)言】：英文

【資料格式】：PDF

【資料目錄和簡(jiǎn)介】：

CONTENTS
Recommendation Q.703 (03/93)
Page
1 General.......................................................................................................................................................... 1
1.1 Introduction ..................................................................................................................................... 1
1.2 Signal unit delimitation and alignment ............................................................................................. 1
1.3 Error detection ................................................................................................................................. 1
1.4 Error correction................................................................................................................................ 2
1.5 Initial alignment............................................................................................................................... 3
1.6 Signalling link error monitoring ....................................................................................................... 3
1.7 Link state control functions .............................................................................................................. 3
1.8 Flow control..................................................................................................................................... 3
2 Basic signal unit format................................................................................................................................. 3
2.1 General............................................................................................................................................. 3
2.2 Signal unit format ............................................................................................................................. 5
2.3 Function and codes of the signal unit fields ..................................................................................... 5
2.4 Order of bit transmission .................................................................................................................. 7
3 Signal unit delimitation ................................................................................................................................. 7
3.1 Flags................................................................................................................................................. 7
3.2 Zero insertion and deletion ............................................................................................................... 7
4 Acceptance procedure ................................................................................................................................... 7
4.1 Acceptance of alignment .................................................................................................................. 7
4.2 Error detection ................................................................................................................................. 7
5 Basic error correction method ........................................................................................................................ 8
5.1 General............................................................................................................................................. 8
5.2 Acknowledgements (positive acknowledgement and negative acknowledgement) ......................... 9
5.3 Retransmission................................................................................................................................. 10
6 Error correction by preventive cyclic retransmission..................................................................................... 11
6.1 General............................................................................................................................................. 11
6.2 Acknowledgements.......................................................................................................................... 12
6.3 Preventive cyclic retransmission....................................................................................................... 13
6.4 Forced retransmission ....................................................................................................................... 14
7 Initial alignment procedure ............................................................................................................................ 14
7.1 General............................................................................................................................................. 14
7.2 Initial alignment status indications ................................................................................................... 14
7.3 Initial alignment procedure............................................................................................................... 15
7.4 Proving periods................................................................................................................................ 17
8 Processor outage............................................................................................................................................ 17
9 Level 2 flow control ...................................................................................................................................... 18
9.1 General............................................................................................................................................. 18
9.2 Detection of congestion .................................................................................................................... 18
9.3 Procedure in the congestion situation ............................................................................................... 18
9.4 Congestion abatement procedure...................................................................................................... 18
ii Recommendation Q.703 (03/93)
Page
10 Signalling link error monitoring..................................................................................................................... 18
10.1 General............................................................................................................................................. 18
10.2 Signal unit error rate monitor............................................................................................................ 19
10.3 Alignment error rate monitor............................................................................................................ 20
11 Level 2 codes and priorities ........................................................................................................................... 20
11.1 Link status signal unit....................................................................................................................... 20
11.2 Transmission priorities within level 2............................................................................................... 21
12 State transition diagrams, abbreviations and timers ....................................................................................... 22
12.2 Abbreviations................................................................................................................................... 22
12.3 Timers .............................................................................................................................................. 24