ITU-T O.163 PDF

General

This specification describes frame alignment signal monitoring equipment for 1544 kbit/s frame structures that are in accordance with Recommendation G.704 [1]. This equipment is intended to monitor 12-frame multiframe (superframe format – SF) or 24-frame multiframe (extended superframe format – ESF) structures having either AMI or B8ZS line codes as defined in § 2 of Recommendation G.703 [2].

This equipment shall provide the following capabilities:

a) monitor and display the error performance of the frame alignment signal;

b) detect and accumulate the counts of occurrences of loss of frame alignment;

c) measure and display the error performance of 24-frame multiframe signals by monitoring the cyclic redundancy check (CRC-6) bits and performing a CRC-6 procedure in accordance with Recommendation G.704 [1] and as described below;

d) detect and display the various alarm or fault conditions including loss of signal, loss of frame alignment, and other alarm conditions indicated by specific bit patterns.

The equipment may optionally provide the following additional capabilities:

a) detect and display the code violations in the 1544 kbits signal in accordance with Recommendation O.161;

b) provide an external interface for extracting the information bits conveyed in any selected channel time slot;

c) provide an external interface for extracting the 4 kbit/s data link bits defined in the 24-frame multiframe structure;

d) provide an external interface for extracting the signalling bits in the 12-frame and 24-frame structures.