Why Do VoIP Calls Fail Only From a Specific Office Network?

The office firewall, NAT, DNS, VLAN, or ISP path may differ from locations where calls work.

Checks to make

Compare a call from a known-good network, record signaling and media symptoms, and review firewall and NAT logs for provider destinations. Check DNS and address translation, and coordinate any required allowlist changes with the voice provider.

When to get help

VoIP support can isolate site network and provider routing issues. Informatix Systems can assess the symptoms, evidence, and next steps. Contact Informatix Systems to discuss this issue.