General

This Recommendation sets out the fundamental parameters of a transmission scheme that should be used for 48-kbit/s data signalling rate for interworking of networks that make use of the following structures:

a) 8-bit envelope (see Explanatory Notes 1 and 2 of Recommendation X.50);

b) 10-bit envelope (see Explanatory Note 3 of Recommendation X.50); in the case where at least one of the networks is structured according to a).

For interworking between two networks both of which utilize the 10-bit envelope structure as identified in § 1.1 b) above, Recommendation X.51 bis will apply.

Paragraph 2 of this Recommendation deals with the basic parameters which shall be used in any application of this Recommendation and, in particular, for interworking between two networks, both of which utilize the 8-bit envelope structure.

Paragraph 3 of this Recommendation, in addition to § 2, applies to the interworking of networks with different envelope structures.

The use of the status bit, in addition to the indication given in this Recommendation, should comply with Recommendation X.21 and X.21 bis, together with Recommendation X.71 for connections using decentralized signalling and with Recommendation X.60 for connections using common channel signalling.