SIP Response Codes in Call Logs

SIP response codes in Call Logs provide detailed information about how inbound calls were processed. These codes help identify call failures, SIP signaling issues, redirection events, and other outcomes, making them essential for troubleshooting and analyzing call behavior.

SIP Response Code Categories

SIP response code groups follow RFC 3261 and categorize call outcomes based on the type of SIP signaling response.

Code	Category	Description
2xx	Successful	The request succeeded and the call was answered or completed normally.
3xx	Redirection	Additional routing or redirection is required to complete the request.
4xx	Client Error	The request could not be processed due to an issue on the caller or endpoint side (e.g., 400, 403, 404).
5xx	Server Error	The destination server encountered an internal error or is unable to process the request.
6xx	Global Failure	The request cannot be completed by any destination.

Disconnect Initiator

Call Logs include a Disconnect Initiator that indicates which side ended the call.

Value	Description
System	The DIDWW platform terminated the call due to configuration limits, timeout, or insufficient balance, or internal logic.
Origination	The calling party or upstream network terminated the call before or during delivery.
Destination	The customer’s SIP endpoint terminated the call.

SIP Response Codes

Disconnect initiator	SIP code	Reason	Description
Destination / Origination	200	Bye	Standard SIP response indicating that the call was successfully connected and then terminated by either the Origination or Destination side.
System		RTP Timeout (Destination)	No RTP was received from the destination within the configured RTP timeout value.
System		RTP Timeout (Origination)	No RTP was received from the origination side within the configured RTP timeout value.
System		Teardown	The call was disconnected because the prepaid balance was depleted during the call.
System		Transfer Failed	The call transfer failed on the destination side.
Destination	300	Multiple Choices	Standard SIP response from the destination indicating that the request resolved to several possible locations, allowing the user or UA to choose a preferred endpoint.
Destination	301	Moved Permanently	Standard SIP response from the destination indicating that the user has permanently moved to the address provided in the Contact header.
Destination	302	Moved Temporarily	Standard SIP response from the destination indicating that the request should be retried at the temporary address provided in the Contact header.
Destination	305	Use Proxy	Standard SIP response from the destination indicating that the requested resource must be accessed through the proxy specified in the Contact header.
Destination	380	Alternative Service	Standard SIP response from the destination indicating that the call was not successful but alternative services are available.
Destination / System	400	Bad Request	Standard SIP response indicating that the request could not be processed due to malformed syntax.
Destination	401	Unauthorized	Standard SIP response from the destination indicating that the request requires user authentication.
System	402	Customer balance too low	The call failed due to insufficient balance on the customer’s account.
Destination	402	Payment Required	Standard SIP response from the destination indicating that payment is required.
System	403	Customer blocked	Inbound call services are not enabled for this account.
System		DID Blocked	The DID number is expired or canceled.
Destination / System		Forbidden	Standard SIP response was returned by the destination side, or the requested commercial feature (e.g., a specific rate or billing option) is not supported.
System		No trunk assigned	The call was rejected because no trunk is assigned to this DID.
System		Rejected by trunk settings	The call was rejected according to the configured Number List rules.
Destination	404	Not Found	Standard SIP response from the destination indicating that the requested user or resource does not exist at the specified address.
Destination	405	Method Not Allowed	Standard SIP response from the destination indicating that the SIP method is understood but not permitted for the requested resource.
Destination	406	Not Acceptable	Standard SIP response from the destination indicating content characteristics not acceptable under the request’s Accept header.
Destination	407	Proxy Authentication Required	Standard SIP response from the destination indicating proxy authentication is required.
System	408	NoAck	No Acknowledgment (ACK) was received from the originating side, causing the call to terminate. The call may appear as connected in logs.
System / Destination	408	Request Timeout	Standard SIP timeout indicating that no response was received from the destination within the required timeframe.
Destination	409	Conflict	Standard SIP response from the destination indicating a conflict in state (e.g., overlapping dialogs or resource conflict).
Destination	410	Gone	Standard SIP response from the destination indicating the requested resource is permanently unavailable and no forwarding address is known.
Destination	412	Conditional Request Failed	Standard SIP response from the destination indicating that a conditional request could not be satisfied.
Destination	413	Request Entity Too Large	Standard SIP response from the destination indicating that the request body is larger than the server is willing or able to process.
Destination	414	Request-URI Too Long	Standard SIP response from the destination indicating that the Request-URI is longer than the server is willing to interpret.
Destination	415	Unsupported Media Type	Standard SIP response from the destination indicating that the request body uses a media format not supported for the requested method.
Destination	416	Unsupported URI Scheme	Standard SIP response from the destination indicating that the URI scheme in the Request-URI is unknown to the server.
Destination	417	Unknown Resource-Priority	Standard SIP response from the destination indicating an unsupported Resource-Priority value.
Destination	420	Bad Extension	Standard SIP response from the destination indicating that a required protocol extension is not supported.
Destination	421	Extension Required	Standard SIP response from the destination indicating that a required extension is not included in the request’s Supported header.
Destination	422	Session Interval Too Small	Standard SIP response from the destination indicating that the requested session interval is too short.
Destination	423	Interval Too Brief	Standard SIP response from the destination indicating that the requested expiration time of the refreshed resource is too short.
Destination	424	Bad Location Information	Standard SIP response from the destination indicating that the location information provided in the request is invalid or unusable.
Destination	428	Use Identity Header	Standard SIP response from the destination indicating that an Identity header is required to authenticate the request.
Destination	429	Provide Referrer Identity	Standard SIP response from the destination indicating that the request must include a valid Referred-By header to provide referrer identity.
Destination	433	Anonymity Disallowed	Standard SIP response from the destination indicating that the request was rejected because anonymous origins are not permitted.
Destination	436	Bad Identity-Info	Standard SIP response from the destination indicating that the Identity-Info header contains invalid or unusable identity information.
Destination	437	Unsupported Certificate	Standard SIP response from the destination indicating that the certificate referenced in the Identity-Info header is unsupported.
Destination	438	Invalid Identity Header	Standard SIP response from the destination indicating that the Identity header is invalid or cannot be verified.
System	480	Capacity limit for DID exceeded	The call was rejected because the DID exceeded its assigned capacity limits.
System		Capacity limit for trunk exceeded	The call was rejected because the trunk exceeded its configured capacity limits.
System		Capacity limit for trunk group exceeded	The call was rejected because the trunk group exceeded its configured capacity limits.
System		Dedicated channels capacity exceeded	The call was rejected because the DID exceeded its dedicated channel capacity.
System		Metered channels capacity exceeded	The call was rejected because no metered channels were available in the assigned capacity group.
System		Shared channels capacity exceeded	The call was rejected because no shared channels were available in the assigned capacity group.
Destination		Temporarily Unavailable	Standard SIP response from the destination indicating that the callee’s end system was contacted successfully but the callee is currently unavailable.
Destination	481	Call/Transaction Does Not Exist	Standard SIP response from the destination indicating that the request does not match any existing dialog or transaction.
Destination	482	Loop Detected	Standard SIP response from the destination indicating that a signaling loop was detected.
Destination	483	Too Many Hops	Standard SIP response from the destination indicating that the request contains a Max-Forwards header field with a value of zero.
Destination	484	Address Incomplete	Standard SIP response from the destination indicating that the Request-URI is incomplete.
Destination	485	Ambiguous	Standard SIP response from the destination indicating that the Request-URI is ambiguous.
Destination	486	Busy Here	Standard SIP response from the destination indicating that the callee was reached but is currently not willing or able to accept the call.
Destination	487	Request Terminated	Standard SIP response from the destination indicating that the request was terminated by a BYE or CANCEL request.
System	487	Ringing timeout	The call was terminated because no answer was received within the configured ringing timeout on the trunk.
System	488	No matching codecs	No matching codecs were found during SDP negotiation between the origination and destination. A live SIP trace is required for full analysis.
Destination	488	Not Acceptable Here	Standard SIP response from the destination indicating that the media or session parameters are not acceptable for this resource.
Destination	489	Bad Event	Standard SIP response from the destination indicating that the event package specified in the request is not supported.
Destination	491	Request Pending	Standard SIP response from the destination indicating that the request cannot be processed because another request is already pending within the same dialog.
Destination	493	Undecipherable	Standard SIP response from the destination indicating that the request contained an encrypted MIME body that could not be decrypted due to missing or unusable decryption keys.
Destination	494	Security Agreement Required	Standard SIP response from the destination indicating that a security agreement is required before the request can be processed.
System	500	Reinvite error	The re-INVITE could not be processed on the customer side due to invalid or unsupported signaling.
System		SDP empty answer	An SDP answer was received with an empty or missing body.
System		SDP inv streams types	An unsupported or invalid media stream type was negotiated in the SDP.
System		SDP invalid streams count	The number of media streams in the SDP answer did not match the streams offered.
System		SDP processing exception	An SDP parsing or processing error occurred. A call signaling trace is required to determine the exact cause.
System		Transfer Failed: EarlyBye	The call transfer failed because the transaction was terminated by an early BYE before completion.
System / Destination		Server Internal Error	Standard SIP response from the destination indicating that the server encountered an unexpected condition and could not fulfill the request.
Destination	501	Not Implemented	Standard SIP response from the destination indicating that the server does not support the functionality required to process the request.
Destination	502	Bad Gateway	Standard SIP response from the destination indicating that a gateway or proxy received an invalid response from a downstream server.
Destination	503	Service Unavailable	Standard SIP response from the destination indicating that the server is temporarily unable to process the request due to overload or maintenance.
Destination	504	Server Time-out	Standard SIP response from the destination indicating a timeout waiting for a downstream server.
Destination	505	Version Not Supported	Standard SIP response from the destination indicating that the SIP protocol version used in the request is not supported.
Destination	513	Message Too Large	Standard SIP response from the destination indicating that the request message was too large to process.
Destination	580	Precondition Failure	Standard SIP response from the destination indicating that a required precondition could not be met for the session.
Destination	600	Busy Everywhere	Standard SIP response from the destination indicating that the callee’s end system was contacted successfully but the callee is busy and does not wish to take the call.
System / Destination	603	Decline	Standard SIP response from the destination indicating that the callee was successfully reached but explicitly does not wish to or cannot accept the call.
Destination	604	Does Not Exist Anywhere	Standard SIP response from the destination indicating that the user in the Request-URI does not exist anywhere according to authoritative information.
Destination	606	Not Acceptable	Standard SIP response from the destination indicating that the user was reached but cannot support the requested session parameters (e.g., media, bandwidth, or addressing).
Destination	607	Unwanted	Standard SIP response from the destination indicating that the caller is not authorized or the callee does not wish to receive calls from this source.
Destination	608	Rejected	Standard SIP response from the destination indicating that the call was rejected by the called party or network.