Cisco Voice Gateways

Cisco CallManager assumes all loop-start trunks lack positive disconnect supervision. We recommend that you configure trunks that have positive disconnect supervision with ground start signaling.

•Foreign Exchange Station (FXS)—Use FXS ports to connect to any plain old telephone service (POTS) device such as analog phones, fax machines, and legacy voice-mail systems.

•T1 PRI—Use this interface to designate North American ISDN Primary Rate Interface (PRI) with 23 bearer channels and one common channel signaling (CCS) channel.

•E1 PRI—Use this interface to designate European ISDN Primary Rate Interface (PRI) with 30 bearer channels, one CCS channel, and one framing voice engineer channel.

•T1 CAS—Use this interface to designate T1 channel-associated signaling (CAS), where each channel includes a dedicated signaling element. The supported signaling interface types include E&M, ground start, and loop start.

•QSIG—Use this protocol to connect with digital PBXs that use common channel signaling protocol based on ISDN Q.931 standards. Cisco CallManager supports QSIG basic call and ID services for certain MGCP-controlled gateways and for PBXs.

Cisco supports basic call services for the following features:

–Calling Line Identification Presentation (CLIP) –Connected Name Identification Presentation (CNIP) –Connected Name Identification Presentation (CONP) –Calling/Connected Line Identification Restriction (CLIR)

The type of PBX determines which QSIG ID services are supported. Refer to the Cisco IP Telephony Network Design Guide for details about compatible PBX software loads, configuration and operational caveats for QSIG protocol.