The Voice T1 and Services Module allows larger enterprises to connect the PSTN and legacy PBXs directly into the campus multiservice network. The Cisco Catalyst 6608 gateway supports Skinny Gateway Control Protocol (SGCP) as well as Media Gateway Control Protocol (MGCP) when used in conjunction with Cisco CallManager 3.1. Gateway failover support is provided using the MGCP protocol.The Voice T1 and Services Module provides transcoding and conferencing services for the multiservice network. Transcoding enables a full voice-compression solution by offering transcoding services to endpoints not capable of supporting compressed voice or a different encoding type to the remote end.