Each RC/ACO SIP extension supports up to four simultaneous Contact Center calls. Supporting more than four requires additional SIP handset extensions, with one extension acting as the primary extension — see SIP Extensions — that distributes queued calls across the others.

Sizing the Handset Count

The number of handsets needed is roughly the desired simultaneous call count divided by four, plus one additional handset to serve as the primary extension.

For example, supporting 8 simultaneous calls requires 3 SIP handset extensions in CCaaS (and 3 corresponding virtual handsets in RC/ACO) — one extension acting as the primary extension, plus two extensions handling the distributed calls.