Why Do VoIP Calls Drop When a Router Is Replaced?

After a router replacement, VoIP phones may register but calls drop after a few minutes, fail in one direction, or lose audio. Registration and media use different network behavior, so successful sign-in does not prove the voice path is stable. The new router may also apply different NAT, timeout, or traffic-priority settings.

Compare before and after

Document phone VLANs, DNS, DHCP options, provider addresses, media ports, and quality-of-service settings. Check whether the issue affects internal calls, external calls, or only calls through one provider. Compare router logs and call timestamps with the provider's session records.

• Verify the provider's required signaling and media path.
• Check NAT keepalive and session timeout behavior.
• Confirm QoS markings are preserved across the new router.
• Test a wired phone and a softphone separately.

Informatix Systems lists VoIP and business communications services. A network review can compare voice requirements with the new routing configuration. Contact Informatix Systems if calls began dropping after a router change.