Zentrunk Hangup Codes

Source	Description
Customer	Hangup initiated by your infrastructure
Carrier	Hangup initiated by the remote carrier
Zentrunk	Hangup initiated by Plivo

Normal Hangups (3000-3040)

Normal call terminations - typically no action required.

Code	Cause	Description	Next Steps
3000	`normal_hangup`	Normal hangup from carrier	None - call completed normally
3010	`normal_hangup`	Normal hangup from user	None - call completed normally
3020	`rtp_timeout`	Mid-call media timeout	Check network stability. Verify firewall allows RTP ports (10000-20000 UDP)
3030	`insufficient_plivo_credits`	Call ended due to low credits	Add credits. Enable auto-recharge in Console → Billing
3040	`abnormal_hangup_due_to_reinvite`	Re-invite rejected	Check for changes in session parameters during call

Authentication Errors (4000-4060)

Issues with credentials or authorization.

Code	Cause	Description	Next Steps
4000	`bad_request`	Malformed SIP request	Check SIP packet format. Don’t retry without fixing
4010	`unauthorized_by_carrier`	Carrier rejected authentication	Verify carrier credentials are not blacklisted
4020	`unauthorized`	Authentication required	Add correct credentials to trunk configuration
4030	`insufficient_plivo_credits`	No credits to start call	Add credits to your account
4040	`forbidden`	Carrier refused the request	Authorization won’t help - check with carrier
4050	`blacklisted_for_verification`	Number blacklisted by Zentrunk	Contact Plivo support
4060	`forbidden`	PBX authentication failed	Verify credentials on your PBX

Routing Errors (4070-4120)

Issues finding the destination or route.

Code	Cause	Description	Next Steps
4070	`trunk_not_found`	Trunk lookup failed	Verify trunk URI is correct in Console
4080	`route_not_found`	No matching trunk URI	Check incoming call route settings
4090	`destination_not_found`	No route to destination	Verify destination number. Check carrier availability
4100	`prefix_not_supported`	Invalid number prefix	Use correct country prefix for destination
4110	`secure_trunking_disabled`	TLS/SRTP used but not enabled	Enable Secure Trunking or use non-secure transport
4120	`destination_invalid`	Invalid “To” number format	Use E.164 format: +14155551234

Caller ID Errors (4130-4200)

Issues with the caller ID used for the call.

Code	Cause	Description	Next Steps
4130	`incorrect_callerid_non_numeric`	Caller ID is not numeric	Use numeric caller ID only
4140	`incorrect_callerid_too_short`	Caller ID less than 6 digits	Use full phone number as caller ID
4180	`call_rejected_unauthorized`	Authentication failed due to invalid credentials or unauthorized access	Verify your SIP trunk credentials (username/password) or IP ACL configuration. Ensure the trunk’s authentication type matches your setup (digest auth vs IP-based)
4190	`unknown_caller_id`	Non-Plivo number used as caller ID	Use a Plivo-rented number as caller ID
4200	`dno_caller_id`	Caller ID is on Do Not Originate list	Use a different number. This one is inbound-only

Format & Media Errors (4150-4270)

Issues with SIP message format or media negotiation.

Code	Cause	Description	Next Steps
4150	`proxy_authentication_required`	Carrier requires proxy auth	Contact carrier for proxy credentials
4160	`request_timeout_carrier`	No response from carrier	Retry. Check carrier availability
4170	`request_timeout_customer`	No response from your PBX	Check PBX is online and reachable
4220	`unsupported_media_type`	Unsupported codec	Use PCMU, PCMA, or telephone-event codecs
4230	`unsupported_uri_scheme`	Unknown request URI	Check SIP URI format
4270	`session_interval_too_small`	Session-expires too short	Increase session timer interval

URI & Availability Errors (4310-4380)

Issues with origination URIs and temporary unavailability.

Code	Cause	Description	Next Steps
4310	`uri_not_found`	Origination URI not found	Create origination URI and attach to trunk
4320	`uri_invalid`	URI cannot be resolved	Verify domain resolves to valid IP address
4330	`temporary_unavailable`	Zentrunk temporarily unavailable	Retry. May indicate CPS limit reached
4340	`temporary_unavailable`	Callee temporarily unavailable (carrier)	Retry later. Destination may be offline
4350	`temporary_unavailable`	Callee temporarily unavailable (customer)	Check your PBX is online
4360	`call_does_not_exist`	Call ID mismatch	Check for duplicate Call-IDs in your system
4370	`loop_detected`	Call loop detected	Fix routing to prevent loops
4380	`too_many_hops`	Hop limit exceeded	Reduce SIP proxy hops

Call State Errors (4410-4550)

Issues with call state, busy, or cancellation.

Code	Cause	Description	Next Steps
4410	`user_busy`	Destination is busy	Retry later or use voicemail fallback
4420	`carrier_cancelled`	Carrier cancelled the call	Check carrier logs for reason
4430	`sdp_not_acceptable_here`	SDP not supported	Check SDP format compatibility
4440	`request_terminated`	Zentrunk terminated request	Check logs for specific reason
4500	`request_pending`	Another request in progress	Wait for current request to complete
4520	`security_agreement_required`	Security negotiation needed	Implement required security mechanism
4540	`forbidden`	Zentrunk auth failure	Contact Plivo support
4550	`user_cancelled`	User cancelled the call	None - caller hung up before answer

Geo & Number Restrictions (4560-4650)

Calls blocked due to permissions or regulations.

Code	Cause	Description	Next Steps
4560	`barred_country`	Country blocked in geo permissions	Enable country in Console → Geo Permissions
4570	`barred_number`	Number is barred	Contact support if this is unexpected
4580	`invalid_sip_packet`	Malformed SIP packet	Check SIP headers and request format
4590	`domestic_anchored_terms_not_met`	India media anchoring violation	For India calls: server must be in India. Don’t mix PSTN and WebRTC in conferences
4650	—	Number blocked in geo permissions settings (SIP response 403 - Barred Country); calls to the barred country or number group don’t go through	If geo permissions were disabled by Plivo, contact support to re-enable them

SDP & Codec Errors (4610-4640)

Issues with session description protocol or codecs.

Code	Cause	Description	Next Steps
4610	`ruri_not_acceptable_here`	Unsupported Request-URI	Check URI format
4620	`codec_not_acceptable_here`	Unsupported codec	Use PCMU, PCMA, or telephone-event
4630	`sdp_not_acceptable_here_by_carrier`	Carrier rejected SDP	Check SDP compatibility with carrier
4640	`sdp_not_acceptable_here_by_user`	Your PBX rejected SDP	Check SDP settings on your PBX

Server & Capacity Errors (5000-5200)

Server-side issues and capacity limits.

Code	Cause	Description	Next Steps
5000	`service_unavailable_no_more_destinations`	No available routes	Retry. Check carrier status
5010	`port_limit_reached`	Maximum port capacity reached	Contact support to increase capacity
5020	`not_implemented`	Unsupported functionality	Check Zentrunk supported features
5030	`not_implemented_at_carrier`	Carrier doesn’t support request	Use different request method
5040	`not_implemented_at_user`	Your PBX doesn’t support request	Update PBX configuration
5180	`cps_limit_reached`	Calls per second limit exceeded	Reduce call rate or contact support to increase CPS
5190	`concurrent_call_limit_exceeded`	Too many simultaneous calls	Wait or contact support to increase limit
5200	`server_timeout`	Timer expired	Retry the request

Mid-Call & Service Errors (5220-5360)

Errors occurring during active calls.

Code	Cause	Description	Next Steps
5220	`service_interrupted_by_customer`	4xx error during call (customer)	Check your PBX logs
5230	`service_interrupted_by_customer`	5xx/6xx error during call (customer)	Check your PBX logs
5240	`service_interrupted_by_nomedia`	Media error during call	Check network connectivity, NAT settings
5250	`internal_error`	Backend service issue	Retry. Contact support if persistent
5260	`internal_error_routing`	Internal routing issue	Retry. Contact support if persistent
5270	`internal_error_media_service`	Media server issue	Retry. Contact support if persistent
5290	`internal_error_trunk`	Trunk URI fetch error	Retry. Verify trunk configuration
5300	`bad_gateway`	Carrier returned 502	Check carrier status
5310	`service_interrupted_by_carrier_4xx`	4xx error during call (carrier)	Check carrier logs
5320	`service_interrupted_by_carrier_5xx_6xx`	5xx/6xx error during call (carrier)	Check carrier status
5330	`server_timeout`	Carrier timeout	Retry. Check carrier availability
5340	`server_timeout`	Your PBX timeout	Check PBX is responsive
5350	`service_unavailable_by_carrier`	Carrier temporarily unavailable	Retry later
5360	`service_unavailable_by_user`	Your PBX temporarily unavailable	Check PBX status

Global Failures (6000-6070)

Final failures with no alternatives.

Code	Cause	Description	Next Steps
6000	`busy_everywhere`	All destinations busy	Retry later. No voicemail available
6020	`does_not_exist_anywhere`	User doesn’t exist	Verify the destination number
6030	`alloted_timeout`	Answer timeout exceeded	Destination took too long to answer
6040	`declined_from_carrier`	Carrier declined the call	Contact carrier for reason
6070	`not_acceptable`	Session description not acceptable	Check SDP compatibility

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