Troubleshooting SIP Trunking Issues

Find the issue you see in the tables below, then open its article for the full fix. Most SIP Trunk issues come from credentials, firewall and network settings, or caller ID rules, so start with the quick checks.

Check the SIP service status

Before you troubleshoot your own setup, check whether the issue is on the CommPeak side. The card below shows the live status of the CommPeak voice network, including the regional SIP servers. If it shows an issue or scheduled maintenance, wait for it to clear before you change any settings, and open the card for incident updates.

Voice (SIP) services

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Check these first

Run these checks before you open an article. They solve many connection and audio issues.

Make sure the SIP credentials on your PBX, IP phone, or softphone match your SIP account. See SIP Account Configuration.
Make sure your firewall and router allow SIP and RTP traffic to and from CommPeak. See PBX VoIP Network and Firewall Best Practices.
Test your connection with the CommPeak Speed Test, and check your audio and keypad tones with Running an Echo and DTMF Test.
Check Realtime System Status for ongoing service incidents.

Connecting calls and caller ID

Use these articles when calls do not connect, devices do not register, or the wrong number shows.

Issue	What you see	Common causes
Call Connection Failures	Outgoing or incoming calls do not connect	Incorrect trunk credentials or an unregistered trunk, DNS resolution problems on your PBX
Extension Registration Issues	An IP phone or softphone fails to register	Incorrect credentials, firewalls or routers that block SIP registration, incorrect extension details, SIP account issues
Incorrect Caller ID Display	The caller ID shows the wrong number or no number	Caller ID settings on your PBX, a provider that overrides the caller ID

Call audio

Use these articles when calls connect but the sound is wrong or the call drops.

Issue	What you see	Common causes
One-Way Audio	Only one side of the call can hear the other	Firewall settings, NAT traversal
Choppy or Distorted Audio	Voices break up or sound distorted	Network Jitter, low bandwidth, IP not added to Network Monitor - Pinger, strict firewalls
Echo During Calls	Participants hear their own voices back	Acoustic feedback, Network Latency, low sound quality
Dropped Calls	Calls disconnect in the middle of a conversation	Network issues, hardware issues

Still need help?

For caller ID setup, see Caller ID Numbers and Caller ID Rules. If none of the articles solve the issue, contact CommPeak Support and include the dialed number and the time of the call.