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مشاهدة النسخة كاملة : What are the diffferences between Q.93B, Q.931, and Q.2931?



A7med Baraka
04-15-2009, 08:48 PM
Essentially, Q.93B is an enhanced signalling protocol for call
control at the Broadband-ISDN user-network interface, using the ATM
transfer mode. The most important difference is that unlike Q.931
which manages fixed bandwidth circuit switched channels, Q.93B has
to manage variable bandwidth virtual channels. So, it has to deal
with new parameters such as ATM cell rate, AAL parameters (for
layer 2), broadband bearer capability, etc. In addition, the ATM
Forum has defined new functionality such as point-to-multipoint
calls. The ITU-T Recommendation will specify interworking
procedures for narrowband ISDN.

Note that as of Spring 1994, Q.93B has reached a state of maturity
susfficient to justify a new name, Q.2931 for its publised official
designation.