Troubleshooting#

Use inbound Call Logs to check how DIDWW processed an inbound call. Each routing attempt shows a SIP response code and the side that ended the call. Use this information to find the cause of a failed call and the setting to change.

Find a failed call#

  1. Go to Logs & Analytics > Call Logs and select Inbound.

  2. Set Date / time start (UTC) to the time range of the call.

  3. Filter by Source, Destination DID, or Voice IN Trunk. To filter by Trunk group, Capacity group, Type, or Call ID, select it in the Filters menu first. See Inbound Call Logs for all filters.

  4. Set Status to Failed or Capacity Exceeded to show only unsuccessful calls.

  5. Check the Response and Disconnect Initiator fields of the call.

When a call is routed through a Trunk Group, each routing attempt produces a separate log entry. The Attempt field shows the attempt number (1 for the first try, 2 for the first failover, and so on), and Voice IN Trunk shows the trunk used for that attempt. DNS SRV failover is transparent and always produces a single log entry.

When the Disconnect Initiator is Destination, the response comes from your SIP endpoint or PBX. Check its logs for the reason. When it is System, DIDWW ended the call. Find the Response in the sections below and open the matching entry. For all codes, see SIP response codes reference.

Call rejected before delivery#

402 Customer balance too low

The account balance is too low to receive the call.

  1. Add funds to your account balance.

  2. To prevent this, enable automatic top-up.

403 No trunk assigned

The DID number has no voice trunk assigned, so DIDWW has nowhere to deliver the call.

  1. Go to Phone Numbers > My Numbers.

  2. Find the DID number. If no trunk is assigned, the trunk field shows Voice: none. See Inbound voice trunk values.

  3. Assign a SIP trunk, PSTN trunk, or Trunk Group. See Assign a voice trunk.

403 Rejected by trunk settings

The calling number was rejected by the Number List selected in the trunk’s CLI Number List field.

  1. Open the trunk and check CLI Number List on the Number Translations tab. See SIP trunk Number Translations or PSTN trunk Number Translations.

  2. Open the Number List and check its Mode, Default action, and item actions.

  3. For a SIP trunk, check that the items use the calling-number format produced by the trunk’s CLI Format and CLI Prefix settings.

  4. Edit or delete the item that rejected the call, or edit the Number List to change its Default action.

For details, see Identify calls rejected by a Number List.

403 DID Blocked

The DID number is expired or canceled, so DIDWW does not deliver calls to it.

  1. Go to Phone Numbers > My Numbers and check the number’s Status.

  2. If the number is expired, renew it.

Capacity exceeded#

Calls rejected by a capacity limit show 480 in the Response field and the Capacity Exceeded status. The reason shows which limit was reached.

480 Capacity limit for trunk exceeded

The trunk already carries the maximum number of simultaneous calls set in its Capacity Limit field.

  1. Open the trunk and check Capacity Limit. See SIP trunk General settings or PSTN trunk General settings.

  2. Edit the SIP trunk or Edit the PSTN trunk to increase the limit or clear it.

Capacity Limit can restrict, but cannot increase, the capacity assigned to a DID number.

480 Capacity limit for trunk group exceeded

The Trunk Group already carries the maximum number of simultaneous calls set in its Capacity Limit field.

  1. Open the Trunk Group and check Capacity Limit.

  2. Edit the Trunk Group to increase the limit or clear it.

480 Capacity limit for DID exceeded

The DID number exceeded its assigned capacity limits.

  1. View capacity usage for the number.

  2. Check or change the number’s limits. See Set capacity limits.

See How capacity works.

480 Dedicated, Metered, or Shared channels capacity exceeded

No channels of that type were available for the call.

  • Dedicated channels capacity exceeded: the DID exceeded its dedicated channel capacity.

  • Metered channels capacity exceeded: no metered channels were available in the assigned Capacity group.

  • Shared channels capacity exceeded: no shared channels were available in the assigned Capacity group.

View capacity usage, then add flat-rate channels or metered channels. See How capacity works.

Call not answered or not completed#

Ringing timeout

The endpoint sent a ringing (18x) response, but did not answer within the SIP trunk’s Ringing Timeout.

  1. Check that the endpoint answers calls to this number.

  2. Edit the SIP trunk to increase Ringing Timeout or clear it. See Signalling settings.

In a Trunk Group, Ringing Timeout is selected by default in the SIP trunk’s Re-routing Disconnect Codes, so DIDWW tries the next trunk.

Calls fail on every trunk in a Trunk Group

A call routed to a Trunk Group has one log entry for each attempt. Filter by Trunk group and check the Response of each attempt.

  • For SIP member trunks, DIDWW tries the next trunk only when the response is selected in the trunk’s Re-routing Disconnect Codes. By default, all codes are selected except 401 Unauthorized, 486 Busy Here, 503 Service Unavailable, and 603 Decline.

  • If the attempts stop after a SIP trunk, check whether its response is selected in Re-routing Disconnect Codes. See SIP trunk Trunk Group settings.

  • To change the trunk order or weights, see Configure member trunk routing.

See Service failover and load balancing.

Media and SDP issues#

488 No matching codecs

DIDWW and the endpoint found no common codec during SDP negotiation.

  1. Open the SIP trunk and check Codecs on the Media & DTMF tab.

  2. Make sure the endpoint supports at least one selected codec. See Supported codecs.

A live SIP trace is required for full analysis.

RTP Timeout (Destination) or RTP Timeout (Origination)

DIDWW received no media (RTP) within the SIP trunk’s RTP Timeout and disconnected the call. See Media & DTMF settings.

  • RTP Timeout (Destination): DIDWW did not receive media from your endpoint. Check that your firewall allows RTP from DIDWW media addresses and that NAT is configured correctly. See RTP and media and Firewall.

  • RTP Timeout (Origination): DIDWW did not receive media from the caller side.

500 Reinvite error or SDP errors

The endpoint sent signaling or SDP that DIDWW could not process.

  • Reinvite error: the re-INVITE could not be processed due to invalid or unsupported signaling.

  • SDP empty answer: the SDP answer had an empty or missing body.

  • SDP inv streams types: an unsupported or invalid media stream type was negotiated.

  • SDP invalid streams count: the number of media streams in the answer did not match the offer.

  • SDP processing exception: an SDP parsing or processing error occurred.

Check the SDP that your endpoint sends. A call signaling trace is required to determine the exact cause. See SIP connectivity reference.

Call ended during the call#

Teardown

The prepaid balance was depleted during the call, so DIDWW disconnected it. Add funds to your account balance or enable automatic top-up.

Transfer Failed or Transfer Failed: EarlyBye

The call transfer failed on the destination side. EarlyBye means a BYE ended the transaction before the transfer completed.

  1. Check that Max Transfers on the SIP trunk allows transfers. See Signalling settings.

  2. Check that your endpoint completes the transfer. See Configure call transfers.