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Zentrunk uses four-digit hangup codes to identify call issues. Find these codes in the CDR under Zentrunk → Logs in the Plivo console.

Hangup Sources

SourceDescription
CustomerHangup initiated by your infrastructure
CarrierHangup initiated by the remote carrier
ZentrunkHangup initiated by Plivo

Hangup Codes

Normal call terminations - typically no action required.
CodeCauseDescriptionNext Steps
3000normal_hangupNormal hangup from carrierNone - call completed normally
3010normal_hangupNormal hangup from userNone - call completed normally
3020rtp_timeoutMid-call media timeoutCheck network stability. Verify firewall allows RTP ports (10000-20000 UDP)
3030insufficient_plivo_creditsCall ended due to low creditsAdd credits. Enable auto-recharge in Console → Billing
3040abnormal_hangup_due_to_reinviteRe-invite rejectedCheck for changes in session parameters during call
Issues with credentials or authorization.
CodeCauseDescriptionNext Steps
4000bad_requestMalformed SIP requestCheck SIP packet format. Don’t retry without fixing
4010unauthorized_by_carrierCarrier rejected authenticationVerify carrier credentials are not blacklisted
4020unauthorizedAuthentication requiredAdd correct credentials to trunk configuration
4030insufficient_plivo_creditsNo credits to start callAdd credits to your account
4040forbiddenCarrier refused the requestAuthorization won’t help - check with carrier
4050blacklisted_for_verificationNumber blacklisted by ZentrunkContact Plivo support
4060forbiddenPBX authentication failedVerify credentials on your PBX
Issues finding the destination or route.
CodeCauseDescriptionNext Steps
4070trunk_not_foundTrunk lookup failedVerify trunk URI is correct in Console
4080route_not_foundNo matching trunk URICheck incoming call route settings
4090destination_not_foundNo route to destinationVerify destination number. Check carrier availability
4100prefix_not_supportedInvalid number prefixUse correct country prefix for destination
4110secure_trunking_disabledTLS/SRTP used but not enabledEnable Secure Trunking or use non-secure transport
4120destination_invalidInvalid “To” number formatUse E.164 format: +14155551234
Issues with the caller ID used for the call.
CodeCauseDescriptionNext Steps
4130incorrect_callerid_non_numericCaller ID is not numericUse numeric caller ID only
4140incorrect_callerid_too_shortCaller ID less than 6 digitsUse full phone number as caller ID
4190unknown_caller_idNon-Plivo number used as caller IDUse a Plivo-rented number as caller ID
4200dno_caller_idCaller ID is on Do Not Originate listUse a different number. This one is inbound-only
Issues with SIP message format or media negotiation.
CodeCauseDescriptionNext Steps
4150proxy_authentication_requiredCarrier requires proxy authContact carrier for proxy credentials
4160request_timeout_carrierNo response from carrierRetry. Check carrier availability
4170request_timeout_customerNo response from your PBXCheck PBX is online and reachable
4220unsupported_media_typeUnsupported codecUse PCMU, PCMA, or telephone-event codecs
4230unsupported_uri_schemeUnknown request URICheck SIP URI format
4270session_interval_too_smallSession-expires too shortIncrease session timer interval
Issues with origination URIs and temporary unavailability.
CodeCauseDescriptionNext Steps
4310uri_not_foundOrigination URI not foundCreate origination URI and attach to trunk
4320uri_invalidURI cannot be resolvedVerify domain resolves to valid IP address
4330temporary_unavailableZentrunk temporarily unavailableRetry. May indicate CPS limit reached
4340temporary_unavailableCallee temporarily unavailable (carrier)Retry later. Destination may be offline
4350temporary_unavailableCallee temporarily unavailable (customer)Check your PBX is online
4360call_does_not_existCall ID mismatchCheck for duplicate Call-IDs in your system
4370loop_detectedCall loop detectedFix routing to prevent loops
4380too_many_hopsHop limit exceededReduce SIP proxy hops
Issues with call state, busy, or cancellation.
CodeCauseDescriptionNext Steps
4410user_busyDestination is busyRetry later or use voicemail fallback
4420carrier_cancelledCarrier cancelled the callCheck carrier logs for reason
4430sdp_not_acceptable_hereSDP not supportedCheck SDP format compatibility
4440request_terminatedZentrunk terminated requestCheck logs for specific reason
4500request_pendingAnother request in progressWait for current request to complete
4520security_agreement_requiredSecurity negotiation neededImplement required security mechanism
4540forbiddenZentrunk auth failureContact Plivo support
4550user_cancelledUser cancelled the callNone - caller hung up before answer
Calls blocked due to permissions or regulations.
CodeCauseDescriptionNext Steps
4560barred_countryCountry blocked in geo permissionsEnable country in Console → Geo Permissions
4570barred_numberNumber is barredContact support if this is unexpected
4580invalid_sip_packetMalformed SIP packetCheck SIP headers and request format
4590domestic_anchored_terms_not_metIndia media anchoring violationFor India calls: server must be in India. Don’t mix PSTN and WebRTC in conferences
Issues with session description protocol or codecs.
CodeCauseDescriptionNext Steps
4610ruri_not_acceptable_hereUnsupported Request-URICheck URI format
4620codec_not_acceptable_hereUnsupported codecUse PCMU, PCMA, or telephone-event
4630sdp_not_acceptable_here_by_carrierCarrier rejected SDPCheck SDP compatibility with carrier
4640sdp_not_acceptable_here_by_userYour PBX rejected SDPCheck SDP settings on your PBX
Server-side issues and capacity limits.
CodeCauseDescriptionNext Steps
5000service_unavailable_no_more_destinationsNo available routesRetry. Check carrier status
5010port_limit_reachedMaximum port capacity reachedContact support to increase capacity
5020not_implementedUnsupported functionalityCheck Zentrunk supported features
5030not_implemented_at_carrierCarrier doesn’t support requestUse different request method
5040not_implemented_at_userYour PBX doesn’t support requestUpdate PBX configuration
5180cps_limit_reachedCalls per second limit exceededReduce call rate or contact support to increase CPS
5190concurrent_call_limit_exceededToo many simultaneous callsWait or contact support to increase limit
5200server_timeoutTimer expiredRetry the request
Errors occurring during active calls.
CodeCauseDescriptionNext Steps
5220service_interrupted_by_customer4xx error during call (customer)Check your PBX logs
5230service_interrupted_by_customer5xx/6xx error during call (customer)Check your PBX logs
5240service_interrupted_by_nomediaMedia error during callCheck network connectivity, NAT settings
5250internal_errorBackend service issueRetry. Contact support if persistent
5260internal_error_routingInternal routing issueRetry. Contact support if persistent
5270internal_error_media_serviceMedia server issueRetry. Contact support if persistent
5290internal_error_trunkTrunk URI fetch errorRetry. Verify trunk configuration
5300bad_gatewayCarrier returned 502Check carrier status
5310service_interrupted_by_carrier_4xx4xx error during call (carrier)Check carrier logs
5320service_interrupted_by_carrier_5xx_6xx5xx/6xx error during call (carrier)Check carrier status
5330server_timeoutCarrier timeoutRetry. Check carrier availability
5340server_timeoutYour PBX timeoutCheck PBX is responsive
5350service_unavailable_by_carrierCarrier temporarily unavailableRetry later
5360service_unavailable_by_userYour PBX temporarily unavailableCheck PBX status
Final failures with no alternatives.
CodeCauseDescriptionNext Steps
6000busy_everywhereAll destinations busyRetry later. No voicemail available
6020does_not_exist_anywhereUser doesn’t existVerify the destination number
6030alloted_timeoutAnswer timeout exceededDestination took too long to answer
6040declined_from_carrierCarrier declined the callContact carrier for reason
6070not_acceptableSession description not acceptableCheck SDP compatibility

Getting Help

If issues persist after troubleshooting:
  1. Check Debug Logs for detailed call information
  2. Download SIP PCAP from debug logs for analysis
  3. Contact Plivo Support with the Call UUID and hangup code