Cisco UC500 Series Technical Training Manual page 135

7. Click on the SIP Trunk tab and setup the UC520 for SIP trunking to a Service Provider for PSTN
access
o Select "Generic SIP Trunk Provider" from the Service Provider pull down menu
o Set the Registrar Server and Proxy server fields with: 1.1.100.254 which is the SIP PSTN
network setup in the lab
o Under Digest Authentication, set username to 4085xx1200 & password to 1234
o Set "Maximum Number of Calls" to be 4. This parameter controls the number of
concurrent calls supported across the SIP trunk. If the maximum is exceeded, the
outbound call may be blocked, or rollover to secondary PSTN trunk, depending on how
your dial plan is configured.
Cisco Unified Communications Technical Training
LAB 8B: UC520 Multi-site Setup
Page 135 of 171