This Recommendation is a merged revised version of Recommendations G.707, G.708 and G.709 that were approved in Helsinki (03/93) by the WTSC.

This Recommendation provides the requirements for the STM-N signals at the Network Node Interface of a synchronous digital network, including B-ISDN in terms of:

bit rates;

frames structures;

formats for mapping and multiplexing PDH and ATM elements;

functionalities of the overheads.