The PA-SIP is an IP based version of the Natcomm PA device and incorporates a highly-configurable internal SIP engine (ATA). It provides an interface function between a SIP network and an audio system. It automatically answers incoming calls and connects the SIP call to an audio line-out port. Tones are generated by the unit to signal call connection and for programming mode indication. The package comes with a Cat 5 cable, SIP configuration software, power adaptor, interface connection box and user guide.