How do you confirm that the Claro SIP trunk stopped?
With a real call, placed from outside your network, to a number that comes in over the trunk. The response that comes back tells you where along the way the call stopped and why. A green dashboard on the PBX confirms nothing, because it only sees the calls that reach it; a route the carrier stopped delivering does not show up there.
Test both directions. Outbound shows whether the trunk accepts your calls; inbound shows whether your number is still arriving. On a SIP trunk, the two can fail separately.
What does each SIP code and Q.850 cause usually point to?
The signatures below come from SIP and Q.850 and apply to any carrier; they do not describe any particular carrier’s network. When the network sends the Q.850 cause, it appears in the Reason header of the SIP response; on an E1, it comes in the disconnect message. Use the table as a starting point, not a verdict.
| Symptom | SIP code / Q.850 cause | What it usually points to |
|---|---|---|
| Outbound rejected right away | 403 Forbidden or cause 21 | The trunk does not authorize the IP, credentials or caller number |
| Inbound does not arrive and the PBX is empty | No response on your side | The carrier stopped delivering the number |
| Rejected at traffic peaks | 503 with cause 34 | Channels exhausted |
| Rejected at any time | 503 with cause 41 | Temporary failure in the route |
| Number does not exist | 404 Not Found or cause 1 | Number not activated, not routed or being ported |
| Incomplete number | 484 Address Incomplete | Dialed number format differs from what the trunk expects |
| No response to the INVITE | 408 Request Timeout | A device on the route is down, or a firewall is in the path |
| Codec rejected | 488 Not Acceptable Here | Codec lists with no match |
Endless ringing, or a 183 Session Progress followed by silence, also counts as a failure for a number that should answer: the call looks alive and nobody picks up.
What about a Claro E1 trunk?
On an E1 trunk, look at the physical layer first: loss-of-signal or loss-of-frame alarms on the card or gateway point to a problem in the physical medium, before any signaling. With no alarm, the failure usually shows up as Q.850 causes on disconnect, such as cause 38 or 34.
An E1 has 30 voice channels. Blocked channels reduce capacity without taking the trunk down, and the symptom is rejections only at the busiest times.
How do you build a ticket the carrier can investigate?
With data that locates each call in the network’s records: exact time with time zone, origin and destination, Call-ID and the full SIP response. A report that “the trunk went down” carries none of that. Confirm the ticket channel, response time and circuit identifier in your contract.
- Date and time of each attempt, with time zone, and of the last call that worked.
- Calling number (A), called number (B) and the circuit identifier.
- The SIP response line, the
Reasonheader and the Call-ID. - The number of failed attempts and the interval between them.
- Whether the failure affects all destinations or only some, and whether it is inbound, outbound or both.
- On an E1, the alarms and affected channels; in any case, the packet capture, if there is one.
How does Monitor help with a Claro trunk?
Monitor calls the numbers on your trunk at the agreed pace, retries a failure before alerting and opens the incident with the SIP code and Q.850 cause of each call, ready for the ticket. It does not integrate with the carrier or the PBX: it calls the numbers, so it works with any of them.
See how in SIP trunk monitoring.
Frequently asked questions
Does Monitor need access to the Claro trunk?
No. Monitor does not integrate with any carrier or any PBX. 2N5 calls the numbers you choose, from its own platform, the way a customer does. Nothing is installed on the trunk, the SBC or the PBX, and the same monitoring works with any carrier.
Which availability target applies to my trunk?
The one in your contract. Availability target, repair time, how it is measured and compensation vary from contract to contract, so confirm yours. Monitor's SLA reports show the availability of each circuit for the month and the last 12 months, to compare against the target.
The trunk shows as registered, but customers cannot call in. Why?
Because registration and call delivery are different things. The carrier can accept the registration and stop routing your number, or route it somewhere else. The PBX does not see those calls, so only a call placed from the outside, like a customer's, shows that the number does not connect.
What do I do when the carrier says it found no fault?
Send the data that lets them locate each call on their network: time with time zone, calling and called numbers, Call-ID, the SIP response and Q.850 cause, and the number of attempts. A record of several failed calls, at different times, is harder to dismiss than a verbal report.