The system can support SIP trunks through its LAN connection. These are configured using IP Office Manager, they cannot be managed through phone based administration.

In order to support SIP trunks, the system must include the following resources:

SIP Trunk Licenses
These licenses are used to configure the number of simultaneous SIP trunk calls supported, up to a maximum of 20. A The system supports up to  3 channels without licenses.

Voice Compression Channels
These are required to convert between the audio compression methods used for IP telephony and those used for analog and digital trunks. Each IP500 Combination card (up to 2) installed in the system provides 10 voice compression channels for the system. One voice compression channel is used for each SIP call.