B-ISDN user network interface: implementation of performance monitoring functions using SONET overhead

The authors review the UNI (user-network interface) structure and identify operations and maintenance functions required across the UNI. In particular, they discuss the SONET (synchronous optical network) overhead required to support transmission error performance monitoring functions across the UNI. It was proposed that B3 and G1 bytes of the SONET path overhead be used for transmission performance monitoring across the UNI. This proposal was accepted by Standards Committee T1-Telecommunications (T1S1.1). With this minimal set of performance monitoring functions across the UNI, the network can still maintain reliable service to the user without causing undue complexity and additional cost in the user equipment.<
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