Review recurring SIP response patterns
Group recent failures by trunk, destination and response class. Compare them with normal call volume and any provider or dial-plan change during the period.
Recurring SIP response patterns
- Sample full traces for repeated 4xx, 5xx or 6xx outcomes. Confirm which hop produced the final response and whether retries or alternate routes followed.
- Keep a separate count for user-cancelled calls and expected busy outcomes so they do not mask service faults.
Record the sampled Call-IDs, time zone and owner of each unresolved pattern; rotate the routes reviewed next month.
Carry the result forward
Review both counts and proportions. A rise in rejections can be harmless when call volume rises, but a new code on one trunk after a change deserves inspection. Record whether the result was expected, intermittent or a complete service failure.
See the SIP response codes: a practical troubleshooting guide when updating the service record.