Troubleshooting: no national rates, no audio, or won't connect

A few common issues and their fixes:

I'm being charged international rates for a domestic call. National rates require you to present a matching in-country Caller ID and to not withhold it. Check that "hide Caller ID" is disabled on your device, and that a validated or DID number for that country is set as your outbound Caller ID. Verify with test number 1-555-555-0911.

One-way or no audio. This is almost always a NAT/firewall issue. On MicroSIP set NAT traversal to ICE only; on other devices ensure RTP ports (10001–20000) can pass. Test with echo number 4443.

Device won't register. Re-check the SIP proxy sip.transcom.net, the username and password, and try port 5061 (TLS) if 5060 (UDP) is blocked on your network. Confirm your account has an available line free (every account has two).

Key presses don't work in menus. Test DTMF on 4747 and, if needed, switch the device's DTMF mode to RFC 2833.