Communication Manager can shuffle or hairpin call path connections between two IP endpoints. Shuffling is done by rerouting the voice channel away from the usual TDM bus connection and creating a direct IP-to-IP connection. Shuffling and hairpinning are similar because these techniques maintain connection and conversion resources that might not be needed. Connection and conversion resources are preserved depending on the compatibility of the endpoints that are attempting to interconnect.

Shuffling and hairpinning techniques differ in the way that these techniques bypass the unnecessary call-path resources.

Shuffled or hairpinned connections:

• Conserve channels on the G4xx Media Gateway and Avaya Aura® Media Server.

• Bypass the TDM bus, conserving timeslots.

• Improve voice quality by removing unnecessary VoIP-TDM-VoIP conversions.

Shuffling releases more resources on the G4xx Media Gateway and Avaya Aura® Media Server than hairpinning does. Therefore, Communication Manager first checks both endpoints to determine whether Communication Manager meets the criteria for using a shuffled audio connection. If the shuffling criteria are not met, Communication Manager routes the call according to the criteria for hairpinning, if hairpinning is enabled. If hairpinning is not enabled, Communication Manager routes the call to the TDM bus. Both endpoints must connect through the same G4xx Media Gateway and Avaya Aura® Media Server for Communication Manager to shuffle or hairpin the audio connection.

For information on interdependencies that enable hairpinning and shuffling audio connections, see Hairpinning and shuffling administration interdependencies. For Network Address Translation (NAT), see Network Address Translation.