scope:

This European Telecommunication Standard (ETS) details enhancements to the Distributed Queue Dual Bus (DQDB) access method as defined in IEEE Standard 802.6 [1] in order to provide Constant Bit Rate (CBR) connection types for the support of existing services (guaranteed constant bandwidth, specified transfer delay) on MANs, using semi-permanent connections in the range of n x 64 kbit/s to 2 Mbit/s bit rate capability. Therefore, signalling protocol specifications are outside the scope of this ETS.

This ETS does not cover the broadband specific aspects and the interworking of MANs with broadband networks. For the broadband related aspects the CBR services are defined in CCITT Recommendations I.362 and I.363 and the protocol reference model to be used in the Asynchronous Transfer Mode (ATM) based networks to support these services is included in CCITT Recommendation I.321.

Annex B provides the Protocol Implementation Conformance Statement (PICS) proforma for this ETS, in compliance with the relevant requirements, and in accordance with the relevant guidance, given in ISO/IEC 9646-2.