Cisco SPA2102-SF Administration Guide - Page 76

Configuring Voice Services SIP Trunking and Hunt Groups on the SPA8000 4 About SIP Trunking The SIP Trunking feature allows a traditional PBX to seamlessly migrate from PSTN service to VoIP service over a broadband link. The SPA8000 offers up to eight telephone lines to the PBX. Fax PBX System Fax 194488 PBX System SPA8000 Integrated Access Device Internet ITSP The SPA8000 offers four trunk groups, numbered T1, T2, T3, and T4. A SIP-based voice service with an ITSP can be configured on each trunk group with a distinct phone number. Each of the eight SPA8000 lines can be configured either as a standalone line, as in a classic ATA FXS port, or as a trunk line that is associated with a trunk group. • Inbound calling: A trunk group offers a single number for callers to call into the small business, with the capability to programmatically ring one or more trunk lines. • Outbound calling: When a PBX phone makes a call, the PBX selects one of the available trunk lines. The trunk line assumes the Caller ID of the trunk group. Cisco Small Business ATA Administration Guide 76