Main Differences Between UNI 3.1 and Q.2931

Here are the main differences between UNI 3.1 and Q.2931

UNI 3.1 does not support the following messages: ALERTING, PROGRESS, SETUP ACKNOWLEDGE, RESUME, INFORMATION, NOTIFY.

UNI 3.1 adds support for point-to-multipoint calls which is not present in Q.2931. This requires addition of messages (ADD PARTY, ADD PARTY ACKNOWLEDGE, ADD PARTY REJECT, DROP PARTY, DROP PARTY ACKNOWLEDGE) and Information Elements (Endpoint reference IE and Endpoint state IE)

UNI 3.1 SETUP message is different. Called party number IE is mandatory in network-to-user-direction. Connection identifier IE is mandatory in network-to-user direction. End-to-end transit delay is not supported.

UNI 3.1 does not support 64 kb/s-based ISDN Circuit Mode Services

UNI 3.1 does not support RESTART and RESTART ACKNOWLEDGE of all virtual channels within a virtual path.

UNI 3.1 does not support AAL type 2 in AAL parameters IE

ATM traffic descriptor IE is enhanced in UNI 3.1.

UNI 3.1 Defines VPI=0, VCI=5 as the signalling VC.