When caller-id enabled on voice port 2/3 system plays a congestion tone on answer (call never makes it to the Asterisk server), when caller-id is disabled, everything works fine. System is a Cisco 1760 running 12.3(10) on a VIC2-4FXO. dial-peer voice 2 voip description Route Calls to Asterisk destination-pattern 790 session protocol sipv2 session target sip-server dtmf-relay rtp-nte codec g711ulaw no vad sip-ua retry invite 3 retry response 3 retry bye 3 retry cancel 3 timers trying 1000 sip-server ipv4:10.0.1.129 voice-port 2/3 no comfort-noise connection plar 790 caller-id enable Debugging shows (when caller ID is enabled): htsp_pre_connect_disconnect, cdb = 821DB748 cause = 11 Any help would be appreciated!