2002-01 2026-01-07 Adam Roach The table below lists the header fields currently defined for the Session Initiation Protocol (SIP) . Some headers have single-letter compact forms (Section 7.3 of RFC 3261). Header field names are case-insensitive. Standard header fields and messages MUST NOT begin with the leading characters "P-". Existing "P-" header field registrations are considered grandfathered, but new registrations of Informational header fields should not begin with the leading characters "P-" (unless the "P-" would preserve compatibility with an pre-existing unregistered usage of the header field, at the discretion of the Designated Expert). Short forms of header fields MUST only be assigned to standards track header fields. At the discretion of the Designated Expert, a header registration may require a Standards Action. Informational Header Expert Review Standard Header Standards Action Accept Accept-Contact a Accept-Encoding Accept-Language Accept-Resource-Priority Additional-Identity 3GPP TS 24.229 v16.7.0 Alert-Info AlertMsg-Error Allow Allow-Events u Answer-Mode Attestation-Info 3GPP TS 24.229 v15.11.0 Authentication-Info Authorization Call-ID i Call-Info Cellular-Network-Info 3GPP TS 24.229 v13.9.0 Contact m Content-Disposition Content-Encoding e Content-ID Content-Language Content-Length l Content-Type c CSeq Date DC-Info 3GPP TS 24.229 v19.4.1 Encryption (Deprecated) Error-Info Event o Expires Feature-Caps Flow-Timer From f Geolocation Geolocation-Error Geolocation-Routing Hide (Deprecated) History-Info Identity y Identity-Info (deprecated by ) Info-Package In-Reply-To Join Max-Breadth Max-Forwards MIME-Version Min-Expires Min-SE Organization Origination-Id 3GPP TS 24.229 v15.11.0 P-Access-Network-Info P-Answer-State P-Asserted-Identity P-Asserted-Service P-Associated-URI P-Called-Party-ID P-Charge-Info P-Charging-Function-Addresses P-Charging-Vector P-DCS-Trace-Party-ID P-DCS-OSPS P-DCS-Billing-Info P-DCS-LAES P-DCS-Redirect P-Early-Media P-Media-Authorization P-Preferred-Identity P-Preferred-Service P-Private-Network-Indication P-Profile-Key P-Refused-URI-List P-Served-User P-User-Database P-Visited-Network-ID Path Permission-Missing Policy-Contact Policy-ID Priority Priority-Share 3GPP TS 24.229 v13.16.0 Priority-Verstat 3GPP TS 24.229 Priv-Answer-Mode Privacy Proxy-Authenticate Proxy-Authorization Proxy-Require RAck Reason Reason-Phrase Reserved to avoid conflict with . Record-Route Recv-Info Refer-Events-At Refer-Sub Refer-To r Referred-By b Reject-Contact j Relayed-Charge 3GPP TS 24.229 v12.14.0 Replaces Reply-To Request-Disposition d Require Resource-Priority Resource-Share 3GPP TS 24.229 v13.7.0 Response-Key (Deprecated) Response-Source 3GPP TS 24.229 v15.11.0 Restoration-Info 3GPP TS 24.229 v12.14.0 Retry-After Route RSeq Security-Client Security-Server Security-Verify Server Service-Interact-Info 3GPP TS 24.229 v13.18.0 Service-Route Session-Expires x Session-ID SIP-ETag SIP-If-Match Subject s Subscription-State Supported k Suppress-If-Match Target-Dialog Timestamp To t Trigger-Consent Unsupported User-Agent User-to-User Via v Warning WWW-Authenticate Specification Required Christer Holmberg SIP Status code Q.850 Cause value in decimal representation ITU-T Q.850 Preemption Cause value in decimal EMM Cause value in decimal representation 3GPP TS 24.301 subclause 9.9.3.9, Table 9.9.3.9.1 ESM Cause value in decimal representation 3GPP TS 24.301 subclause 9.9.4.4, Table 9.9.4.4.1 S1AP-RNL Radio network layer cause value in decimal representation 3GPP TS 36.413 S1AP-TL Radio network layer cause value in decimal representation 3GPP TS 36.413 subclause 9.2.1.3 S1AP-NAS Non-access stratum cause value in decimal representation 3GPP TS 36.413 subclause 9.2.1.3 S1AP-MISC Miscellaneous cause value in decimal representation 3GPP TS 36.413 subclause 9.2.1.3 S1AP-PROT S1 Protocol cause value in decimal representation 3GPP TS 36.413 subclause 9.2.1.3 DIAMETER Cause for protocol failure of GTP-C supporting WLAN, as a representation in decimal digits of the received binary value. 3GPP TS 29.274 subclause 8.103 IKEV2 Cause for protocol failure of IKEV2 supporting untrusted WLAN, as a representation in decimal digits of the received binary value. 3GPP TS 29.274 subclause 8.103 RELEASE_CAUSE cause value 1: User ends call cause value 2: RTP/RTCP time-out cause value 3: Media bearer loss cause value 4: SIP timeout - no ACK cause value 5: SIP response time-out cause value 6: Call-setup time-out cause value 7: Redirection failure 3GPP TS 24.229 FAILURE_CAUSE cause value 1: Media bearer or QoS lost cause value 2: Release of signalling bearer cause value 3: Indication of failed resources allocation 3GPP TS 24.229 v14.4.0 STIR STIR Error code 5GMM Cause value in decimal representation 3GPP TS 24.501 subclause 9.11.3.2 5GSM Cause value in decimal representation 3GPP TS 24.501 subclause 9.11.4.2 NGAP-RNL Radio network layer cause value in decimal representation 3GPP TS 38.413 subclause 9.3.1.2 NGAP-TL Radio network layer cause value in decimal representation 3GPP TS 38.413 subclause 9.3.1.2 NGAP-NAS Non-access stratum cause value in decimal representation 3GPP TS 38.413 subclause 9.3.1.2 NGAP-MISC Miscellaneous cause value in decimal representation 3GPP TS 38.413 subclause 9.3.1.2 NGAP-PROT S1 Protocol cause value in decimal representation 3GPP TS 38.413 subclause 9.3.1.2 see the separate "Preemption" Registry for default reason-text strings This protocol value can also be used to represent MM cause from 3GPP TS 24.008. The MM causes in 3GPP TS 24.008 use the same decimal value as the causes in 3GPP TS 24.301. The MM causes are specified in 3GPP TS 24.008 in subclause 10.5.5.14, Table 10.5.147. This protocol value can also be used to represent SM cause from 3GPP TS 24.008. The SM causes in 3GPP TS 24.008 use the same decimal value as the causes in 3GPP TS 24.301. The SM causes are specified in 3GPP TS 24.008 in subclause 10.5.6.6, Table 10.5.157. The decimal values for the causes are derived from the ASN.1 encoding in subclause 9.3.4. The decimal values for the causes are derived from the Termination-Cause AVP Values (code 295) registry. The decimal values for the causes are derived from the IKEv2 Notify Message Types - Error Types registry. Standards Action Option tags are used in header fields such as Require, Supported, Proxy-Require, and Unsupported in support of SIP compatibility mechanisms for extensions. The option tag itself is a string that is associated with a particular SIP option (that is, an extension). It identifies the option to SIP endpoints. When this registry is modified, the YANG module iana-sip-option-tags must be updated as defined in . 100rel This option tag is for reliability of provisional responses. When present in a Supported header, it indicates that the UA can send or receive reliable provisional responses. When present in a Require header in a request it indicates that the UAS MUST send all provisional responses reliably. When present in a Require header in a reliable provisional response, it indicates that the response is to be sent reliably. 199 This option-tag is for indicating support of the 199 Early Dialog Terminated provisional response code. When present in a Supported header of a request, it indicates that the UAC supports the 199 response code. When present in a Require or Proxy-Require header field of a request, it indicates that the UAS, or proxies, MUST support the 199 response code. It does not require the UAS, or proxies, to actually send 199 responses. answermode This option tag is for support of the Answer-Mode and Priv-Answer-Mode extensions used to negotiate automatic or manual answering of a request. early-session A UA adding the early-session option tag to a message indicates that it understands the early-session content disposition. eventlist Extension to allow subscriptions to lists of resources explicitsub This option tag identifies an extension to REFER to suppress the implicit subscription and provide a URI for an explicit subscription. from-change This option tag is used to indicate that a UA supports changes to URIs in From and To header fields during a dialog. geolocation-http The "geolocation-http" option tag signals support for acquiring location information via an HTTP . A location recipient who supports this option can request location with an HTTP GET and parse a resulting 200 response containing a PIDF-LO object. The URI schemes supported by this option include "http" and "https". geolocation-sip The "geolocation-sip" option tag signals support for acquiring location information via the presence event package of SIP . A location recipient who supports this option can send a SUBSCRIBE request and parse a resulting NOTIFY containing a PIDF-LO object. The URI schemes supported by this option include "sip", "sips", and "pres". gin This option tag is used to identify the extension that provides Registration for Multiple Phone Numbers in SIP. When present in a Require or Proxy-Require header field of a REGISTER request, it indicates that support for this extension is required of registrars and proxies, respectively, that are a party to the registration transaction. gruu This option tag is used to identify the Globally Routable User Agent URI (GRUU) extension. When used in a Supported header, it indicates that a User Agent understands the extension. When used in a Require header field of a REGISTER request, it indicates that the registrar is not expected to process the registration unless it supports the GRUU extension. histinfo When used with the Supported header field, this option tag indicates the UAC supports the History Information to be captured for requests and returned in subsequent responses. This tag is not used in a Proxy-Require or Require header field, since support of History-Info is optional. ice This option tag is used to identify the Interactive Connectivity Establishment (ICE) extension. When present in a Require header field, it indicates that ICE is required by an agent. join Support for the SIP Join Header multiple-refer This option tag indicates support for REFER requests that contain a resource list document describing multiple REFER targets. norefersub This option tag specifies a User Agent ability of accepting a REFER request without establishing an implicit subscription (compared to the default case defined in . nosub This option tag identifies an extension to REFER to suppress the implicit subscription and indicate that no explicit subscription is forthcoming. outbound This option-tag is used to identify UAs and Registrars which support extensions for Client Initiated Connections. A UA places this option in a Supported header to communicate its support for this extension. A Registrar places this option-tag in a Require header to indicate to the registering User Agent that the Registrar used registrations using the binding rules defined in this extension. path A SIP UA that supports the Path extension header field includes this option tag as a header field value in a Supported header field in all requests generated by that UA. Intermediate proxies may use the presence of this option tag in a REGISTER request to determine whether to offer Path service for for that request. If an intermediate proxy requires that the registrar support Path for a request, then it includes this option tag as a header field value in a Requires header field in that request. policy This option tag is used to indicate that a UA can process policy server URIs for and subscribe to session-specific policies. precondition An offerer MUST include this tag in the Require header field if the offer contains one or more "mandatory" strength-tags. If all the strength-tags in the description are "optional" or "none" the offerer MUST include this tag either in a Supported header field or in a Require header field. pref This option tag is used to ensure that a server understands the callee capabilities parameters used in the request. privacy This option tag indicates support for the Privacy mechanism. When used in the Proxy-Require header, it indicates that proxy servers do not forward the request unless they can provide the requested privacy service. This tag is not used in the Require or Supported headers. Proxies remove this option tag before forwarding the request if the desired privacy function has been performed. recipient-list-invite The body contains a list of URIs that indicates the recipients of the SIP INVITE request recipient-list-message The body contains a list of URIs that indicates the recipients of the SIP MESSAGE request recipient-list-subscribe This option tag is used to ensure that a server can process the recipient-list body used in a SUBSCRIBE request. record-aware This option tag is to indicate the ability of the UA to receive recording indicators in media-level or session-level SDP. When present in a Supported header, it indicates that the UA can receive recording indicators in media-level or session-level SDP. replaces This option tag indicates support for the SIP Replaces header. resource-priority Indicates or requests support for the resource priority mechanism. sdp-anat The option-tag sdp-anat is defined for use in the Require and Supported SIP header fields. SIP user agents that place this option-tag in a Supported header field understand the ANAT semantics as defined in . sec-agree This option tag indicates support for the Security Agreement mechanism. When used in the Require, or Proxy-Require headers, it indicates that proxy servers are required to use the Security Agreement mechanism. When used in the Supported header, it indicates that the User Agent Client supports the Security Agreement mechanism. When used in the Require header in the 494 (Security Agreement Required) or 421 (Extension Required) responses, it indicates that the User Agent Client must use the Security Agreement Mechanism. siprec This option tag is for identifying that the SIP session is for the purpose of an RS. This is typically not used in a Supported header. When present in a Require header in a request, it indicates that the UA is either an SRC or SRS capable of handling a recording session. tdialog This option tag is used to identify the target dialog header field extension. When used in a Require header field, it implies that the recipient needs to support the Target-Dialog header field. When used in a Supported header field, it implies that the sender of the message supports it. timer This option tag is for support of the session timer extension. Inclusion in a Supported header field in a request or response indicates that the UA is capable of performing refreshes according to that specification. Inclusion in a Require header in a request means that the UAS must understand the session timer extension to process the request. Inclusion in a Require header field in a response indicates that the UAC must look for the Session-Expires header field in the response, and process accordingly. trickle-ice This option tag is used to indicate that a UA supports and understands Trickle ICE. uui This option tag is used to indicate that a UA supports and understands the User-to-User header field. Section 27.2 RFC Required Warning codes provide information supplemental to the status code in SIP response messages. 300 Incompatible network protocol: One or more network protocols contained in the session description are not available. 301 Incompatible network address formats: One or more network address formats contained in the session description are not available. 302 Incompatible transport protocol: One or more transport protocols described in the session description are not available. 303 Incompatible bandwidth units: One or more bandwidth measurement units contained in the session description were not understood. 304 Media type not available: One or more media types contained in the session description are not available. 305 Incompatible media format: One or more media formats contained in the session description are not available. 306 Attribute not understood: One or more of the media attributes in the session description are not supported. 307 Session description parameter not understood: A parameter other than those listed above was not understood. 308 Incompatible language specification: Requested languages not supported. Supported languages and media are: [list of supported languages and media]. 330 Multicast not available: The site where the user is located does not support multicast. 331 Unicast not available: The site where the user is located does not support unicast communication (usually due to the presence of a firewall). 370 Insufficient bandwidth: The bandwidth specified in the session description or defined by the media exceeds that known to be available. 380 SIPS Not Allowed: The UAS or proxy cannot process the request because the SIPS scheme is not allowed (e.g., because there are currently no registered SIPS Contacts). 381 SIPS Required: The UAS or proxy cannot process the request because the SIPS scheme is required. 399 Miscellaneous warning: The warning text can include arbitrary information to be presented to a human user or logged. A system receiving this warning MUST NOT take any automated action. Standards Action ACK BYE CANCEL INFO INVITE MESSAGE NOTIFY OPTIONS PRACK PUBLISH REFER REGISTER SUBSCRIBE UPDATE RFC Required All response codes below are defined by unless otherwise noted. 1xx: Provisional 2xx: Successful 3xx: Redirection 4xx: Request Failure 5xx: Server Failure 6xx: Global Failures 100 Trying 180 Ringing 181 Call Is Being Forwarded 182 Queued 183 Session Progress 199 Early Dialog Terminated 200 OK 202 Accepted (Deprecated) 204 No Notification 300 Multiple Choices 301 Moved Permanently 302 Moved Temporarily 305 Use Proxy 380 Alternative Service 400 Bad Request 401 Unauthorized 402 Payment Required 403 Forbidden 404 Not Found 405 Method Not Allowed 406 Not Acceptable 407 Proxy Authentication Required 408 Request Timeout 410 Gone 412 Conditional Request Failed 413 Request Entity Too Large 414 Request-URI Too Long 415 Unsupported Media Type 416 Unsupported URI Scheme 417 Unknown Resource-Priority 420 Bad Extension 421 Extension Required 422 Session Interval Too Small 423 Interval Too Brief 424 Bad Location Information 425 Bad Alert Message 428 Use Identity Header 429 Provide Referrer Identity 430 Flow Failed 433 Anonymity Disallowed 436 Bad Identity Info 437 Unsupported Credential 438 Invalid Identity Header 439 First Hop Lacks Outbound Support 440 Max-Breadth Exceeded 469 Bad Info Package 470 Consent Needed 480 Temporarily Unavailable 481 Call/Transaction Does Not Exist 482 Loop Detected 483 Too Many Hops 484 Address Incomplete 485 Ambiguous 486 Busy Here 487 Request Terminated 488 Not Acceptable Here 489 Bad Event 491 Request Pending 493 Undecipherable 494 Security Agreement Required 500 Server Internal Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable 504 Server Time-out 505 Version Not Supported 513 Message Too Large 555 Push Notification Service Not Supported 580 Precondition Failure 600 Busy Everywhere 603 Decline 604 Does Not Exist Anywhere 606 Not Acceptable 607 Unwanted 608 Rejected IETF Review user Request that privacy services provide a user-level privacy function header Request that privacy services modify headers that cannot be set arbitrarily by the user (Contact/Via). session Request that privacy services provide privacy for session media none Privacy services must not perform any privacy function critical Privacy service must perform the specified services or fail the request id Privacy requsted for Third-Party Asserted Identity history Privacy requested for History-Info header field(s) IETF Review digest tls ipsec-ike ipsec-man ipsec-3gpp Standards Action Signaling Compression sigcomp Standards Action aai No bnc No cause Yes ccxml No comp Yes content-type No delay No duration No extension No gr No iotl Yes locale No lr No m Yes maddr No maxage No maxstale No method "get" / "post" method Yes ob No param[n] No play No pn-param No pn-prid No pn-provider No pn-purr No postbody No repeat No sg No sigcomp-id No target No transport Yes ttl No user Yes voicexml No IETF Review Accept q No Accept-Encoding q No Accept-Language q No Alert-Info appearance No AlertMsg-Error code no Answer-Mode require No Authorization algorithm Yes Authorization auts No Authorization cnonce No Authorization nc No Authorization nonce No Authorization opaque No Authorization qop Yes Authorization realm No Authorization response No Authorization uri No Authorization username No Authentication-Info cnonce No Authentication-Info nc No Authentication-Info nextnonce No Authentication-Info qop Yes Authentication-Info rspauth No Call-Info call-reason No Call-Info integrity No Call-Info m Yes Call-Info purpose Yes Call-Info verified Yes Contact expires No Contact mp No Contact np No Contact pub-gruu No Contact q No Contact rc No Contact reg-id No Contact temp-gruu No Contact temp-gruu-cookie No Content-Disposition handling Yes Event adaptive-min-rate No Event body Yes Event call-id No Event effective-by No Event from-tag No Event id No Event include-session-description No Event max-rate No Event min-rate No Event model No Event profile-type Yes Event shared No Event to-tag No Event vendor No Event version No Feature-Caps fcap-name No From tag No Geolocation loc-src No Geolocation-Error code Yes History-Info mp No History-Info np No History-Info rc No P-Access-Network-Info cgi-3gpp No P-Access-Network-Info ci-3gpp2 No P-Access-Network-Info ci-3gpp2-femto No P-Access-Network-Info dsl-location No P-Access-Network-Info dvb-rcs2-node-id No P-Access-Network-Info eth-location No P-Access-Network-Info fiber-location No P-Access-Network-Info gstn-location No P-Access-Network-Info i-wlan-node-id No P-Access-Network-Info local-time-zone No P-Access-Network-Info operator-specific-GI No P-Access-Network-Info utran-cell-id-3gpp No P-Access-Network-Info utran-sai-3gpp No P-Charging-Function-Addresses ccf No P-Charging-Function-Addresses ccf-2 No P-Charging-Function-Addresses ecf No P-Charging-Function-Addresses ecf-2 No P-Charging-Vector icid-value No P-Charging-Vector icid-generated-at No P-Charging-Vector orig-ioi No P-Charging-Vector related-icid No P-Charging-Vector related-icid-generated-at No P-Charging-Vector term-ioi No P-Charging-Vector transit-ioi No P-DCS-Billing-Info called No P-DCS-Billing-Info calling No P-DCS-Billing-Info charge No P-DCS-Billing-Info jip No P-DCS-Billing-Info locroute No P-DCS-Billing-Info rksgroup No P-DCS-Billing-Info routing No P-DCS-LAES bcid No P-DCS-LAES cccid No P-DCS-LAES content No P-DCS-LAES key (OBSOLETED) No P-DCS-Redirect count No P-DCS-Redirect redirector-uri No P-DCS-Trace-Party-ID timestamp No P-Refused-URI-List members No P-Served-User sescase Yes P-Served-User regstate Yes P-Served-User orig-cdiv No Policy-Contact non-cacheable Yes Priv-Answer-Mode require No Proxy-Authenticate algorithm Yes Proxy-Authenticate authz_server No Proxy-Authenticate domain No Proxy-Authenticate error No Proxy-Authenticate nonce No Proxy-Authenticate opaque No Proxy-Authenticate qop Yes Proxy-Authenticate realm No Proxy-Authenticate scope No Proxy-Authenticate stale Yes Proxy-Authorization algorithm Yes Proxy-Authorization auts No Proxy-Authorization cnonce No Proxy-Authorization nc No Proxy-Authorization nonce No Proxy-Authorization opaque No Proxy-Authorization qop Yes Proxy-Authorization realm No Proxy-Authorization response No Proxy-Authorization uri No Proxy-Authorization username No Reason cause Yes Reason location Yes Reason ppi No Reason text No Retry-After duration No Security-Client alg Yes Security-Client ealg Yes Security-Client d-alg Yes Security-Client d-qop Yes Security-Client d-ver No Security-Client mod Yes Security-Client port1 No Security-Client port2 No Security-Client prot Yes Security-Client q No Security-Client spi No Security-Server alg Yes Security-Server ealg Yes Security-Server d-alg Yes Security-Server d-qop Yes Security-Server d-ver No Security-Server mod Yes Security-Server port1 No Security-Server port2 No Security-Server prot Yes Security-Server q No Security-Server spi No Security-Verify alg Yes Security-Verify ealg Yes Security-Verify d-alg Yes Security-Verify d-qop Yes Security-Verify d-ver No Security-Verify mod Yes Security-Verify port1 No Security-Verify port2 No Security-Verify prot Yes Security-Verify q No Security-Verify spi No Session-ID logme No (no values are allowed) Session-ID remote No Subscription-State adaptive-min-rate No Subscription-State expires No Subscription-State max-rate No Subscription-State min-rate No Subscription-State reason Yes Subscription-State retry-after No Target-Dialog local-tag No Target-Dialog remote-tag No To tag No Trigger-Consent target-uri No User-to-User content No User-to-User encoding Yes User-to-User purpose No Via alias No Via branch No Via comp Yes Via keep No Via maddr No Via oc Yes Via oc-algo Yes Via oc-seq Yes Via oc-validity Yes Via received No Via received-realm No Via rport No Via sigcomp-id No Via ttl No WWW-Authenticate algorithm Yes WWW-Authenticate authz_server No WWW-Authenticate domain Yes WWW-Authenticate error No WWW-Authenticate nonce No WWW-Authenticate opaque No WWW-Authenticate qop Yes WWW-Authenticate realm No WWW-Authenticate scope No WWW-Authenticate stale Yes <fcap-name> denotes parameter names conforming to the syntax <fcap-name> defined in . Valid feature-capability indicators are registered in the Proxy-Feature Feature-Capability Indicator Trees registry. Specification Required Unassigned participation The URI can be used to join the conference streaming The URI can be used to access the streamed conference data event The URI can be used to subscribe to the conference event package recording The URI can be used to access the recorded conference data web-page The URI can be used to access a web page that contains additional information of the conference ccmp The URI can be used to indicate that the conference focus supports CCMP. grouptextchat The URI can be used to join a multi-user chat directly associated with the conference IETF Review Namespace = the unique string identifying the namespace Namespace Numerical Value = the unique numerical value identifying the namespace Levels = the number of priority-values within the namespace Algorithm = Intended operational behavior of SIP elements implementing this namespace New Warn code = New Warning Codes (warn-codes) introduced by this namespace New Resp. code = New SIP response codes introduced by this namespace Reference = IETF document reference for this namespace Namespace Numerical Value = dsn 0 5 preemption no no drsn 1 6 preemption no no q735 2 5 preemption no no ets 3 5 queue no no wps 4 5 queue no no dsn-000000 5 10 preemption no no dsn-000001 6 10 preemption no no dsn-000002 7 10 preemption no no dsn-000003 8 10 preemption no no dsn-000004 9 10 preemption no no dsn-000005 10 10 preemption no no dsn-000006 11 10 preemption no no dsn-000007 12 10 preemption no no dsn-000008 13 10 preemption no no dsn-000009 14 10 preemption no no drsn-000000 15 10 preemption no no drsn-000001 16 10 preemption no no drsn-000002 17 10 preemption no no drsn-000003 18 10 preemption no no drsn-000004 19 10 preemption no no drsn-000005 20 10 preemption no no drsn-000006 21 10 preemption no no drsn-000007 22 10 preemption no no drsn-000008 23 10 preemption no no drsn-000009 24 10 preemption no no rts-000000 25 10 preemption no no rts-000001 26 10 preemption no no rts-000002 27 10 preemption no no rts-000003 28 10 preemption no no rts-000004 29 10 preemption no no rts-000005 30 10 preemption no no rts-000006 31 10 preemption no no rts-000007 32 10 preemption no no rts-000008 33 10 preemption no no rts-000009 34 10 preemption no no crts-000000 35 10 preemption no no crts-000001 36 10 preemption no no crts-000002 37 10 preemption no no crts-000003 38 10 preemption no no crts-000004 39 10 preemption no no crts-000005 40 10 preemption no no crts-000006 41 10 preemption no no crts-000007 42 10 preemption no no crts-000008 43 10 preemption no no crts-000009 44 10 preemption no no esnet 45 5 queue no no mcpttp 46 16 preemption no no mcpttq 47 16 queue no no IETF Review Legend: Namespace Numerical Value = the unique numerical value identifying the namespace Priority Numerical Value: "routine" 5 "priority" 4 "immediate" 3 "flash" 2 "flash-override" 1 "flash-override-override" 0 "routine" 4 "priority" 3 "immediate" 2 "flash" 1 "flash-override" 0 "4" 4 "3" 3 "2" 2 "1" 1 "0" 0 "4" 4 "3" 3 "2" 2 "1" 1 "0" 0 "4" 4 "3" 3 "2" 2 "1" 1 "0" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 9 "1" 8 "2" 7 "3" 6 "4" 5 "5" 4 "6" 3 "7" 2 "8" 1 "9" 0 "0" 4 "1" 3 "2" 2 "3" 1 "4" 0 "mcpttp.0" 15 "mcpttp.1" 14 "mcpttp.2" 13 "mcpttp.3" 12 "mcpttp.4" 11 "mcpttp.5" 10 "mcpttp.6" 9 "mcpttp.7" 8 "mcpttp.8" 7 "mcpttp.9" 6 "mcpttp.10" 5 "mcpttp.11" 4 "mcpttp.12" 3 "mcpttp.13" 2 "mcpttp.14" 1 "mcpttp.15" 0 "mcpttq.0" 15 "mcpttq.1" 14 "mcpttq.2" 13 "mcpttq.3" 12 "mcpttq.4" 11 "mcpttq.5" 10 "mcpttq.6" 9 "mcpttq.7" 8 "mcpttq.8" 7 "mcpttq.9" 6 "mcpttq.10" 5 "mcpttq.11" 4 "mcpttq.12" 3 "mcpttq.13" 2 "mcpttq.14" 1 "mcpttq.15" 0 Standards Action alg info Deprecated and closed per RFC8224 rsa-sha1 rsa-sha256 begins with 'sfua-' RFC Required all other names First Come First Served sfua-id The URN identifying the User Agent, constructed as specified in section 4.1 of "Managing Client-Initiated Connections in the Session Initiation Protocol (SIP)". Since the procedure defined by allows any UA to construct a value for this parameter, the sfua-id parameter MUST always be included. If the UA implements , and includes the '+sip.instance' Contact header field parameter in any request, when requesting configuration it MUST use the same value for the sfua-id parameter. sfua-user An identifier for a user associated with the configuration. Note that this might be different than any SIP 'user' in the UA configuration: it could, for example, be the login name of an account on the service provider web site. The syntax of this parameter is that of the 'userid'. See Section 2.4.1, "Configuration Data Request Authentication" for how this parameter relates to authentication of the configuration data request. sfua-vendor An identifier that specifies the vendor of the User Agent. The syntax of the value of this parameter is that of a DNS domain. The domain value MUST be that of a domain owned by the vendor. sfua-model An identifier that further specifies the User Agent from among those produced by the vendor. The syntax of the value of this parameter is the same as the 'token'. Values for this parameter are selected by the vendor. sfua-revision An identifier that further specifies the User Agent from among those produced by the vendor. The syntax of the value of this parameter is the same as the 'token'. Values for this parameter are selected by the vendor. Specification Required Unassigned 3gpp-service Communication services defined by 3GPP for use by the IM CN subsystem and its attached UAs. This value in itself does not define a service and requires subsequent labels to define the service. 3gpp-application Applications defined by 3GPP for use by UAs attached to the IM CN subsystem. This value in itself does not define a service and requires subsequent labels to define the service. Specification Required Adam Roach g.3gpp.access-transfer-events 3GPP TS 24.237 v11.14.0 g.3gpp.mid-call 3GPP TS 24.237 v10.19.0 g.3gpp.ussd 3GPP TS 24.390 v11.5.0 g.3gpp.state-and-event 3GPP 24.237 Rel-10 EmergencyCallData.eCall.MSD EmergencyCallData.VEDS infoDtmf 3GPP 24.229 v12.16.0 g.3gpp.mcptt-floor-request 3GPP 24.379 v13.7.0, Section J.1.2 g.3gpp.mcptt-info 3GPP 24.379 v13.7.0, Section J.2.2 g.3gpp.mcdata-com-release 3GPP TS 24.282 14.3.0 trickle-ice g.3gpp.mcvideo-info 3GPP TS 24.281 14.3.0 g.3gpp.current-location-discovery 3GPP TS 24.229 Specification Required Unassigned local-network device user Specification Required Unassigned 100 "Cannot Process Location" 200 "Permission to Use Location Information" 201 "Permission to Retransmit Location Information to a Third Party" 202 "Permission to Route Based on Location Information" 300 "Deference Failure" Standards Action deactivated probation rejected timeout giveup noresource invariant badfilter Standards Action g. Global Feature Capability Indicator Tree sip. SIP Feature Capability Indicator Tree Specification Required Paul Kyzivat (primary), Christer Holmberg (secondary) g.3gpp.iut-focus This feature-capability indicator when used in a Feature-Caps header field of a SIP request or a SIP response indicates that the function which inserted the Feature-Caps header field supports anchoring an IUT session. 3GPP TS 24.337 10.7.0 g.3gpp.mid-call This feature-capability indicator when used in a Feature-Caps header field of a SIP request or a SIP response indicates that: 1. the functional entity including the feature-capability indicator in the SIP message supports the MSC server assisted mid-call feature; and 2. all entities of which the functional entity including the feature-capability indicator in the SIP message is aware of being requested to support the feature do support the MSC server assisted mid-call feature. 3GPP TS 24.237 10.10.0 g.3gpp.atcf This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP REGISTER request or a SIP response to the SIP REGISTER request indicates presence and support of a resource which is an Access Transfer Control Function (ATCF) and also the session transfer number allocated to the ATCF. 3GPP TS 24.237 10.10.0 g.3gpp.srvcc-alerting This feature-capability indicator when used in a Feature-Caps header field of a SIP request or a SIP response indicates that: 1. the functional entity including the feature-capability indicator in the SIP message supports access transfer for calls in alerting phase; and 2. all entities of which the functional entity including the feature-capability indicator in the SIP message is aware of being requested to support the feature do support access transfer for calls in alerting phase. 3GPP TS 24.237 10.10.0 g.3gpp.atcf-mgmt-uri This feature-capability indicator when used in a Feature-Caps header field as specified in IETF [60] in SIP REGISTER request indicates presence and support of performing as a UAS for SIP requests for ATCF management received at this URI. 3GPP TS 24.237 10.10.0 g.3gpp.srvcc This feature-capability indicator when included in a Feature-Caps header field as specified in IETF of: - a SIP INVITE request; or - a SIP INVITE response; indicates presence and support of a resource capable of performing the SRVCC access transfer procedure as specified in 3GPP TS 24.237. 3GPP TS 24.237 10.10.0 g.3gpp.atcf-path This feature-capability indicator when used in a Feature-Caps header field as specified in IETF in SIP REGISTER request indicates capability of identifying the registration path and binding SRVCC related information to it. 3GPP TS 24.237 10.10.0 g.3gpp.cs2ps-srvcc This feature-capability indicator when included in Feature-Caps header field as specified in IETF [60] indicates support of the CS to PS single radio voice call continuity as specified in 3GPP TS 24.237. 3GPP TS 24.237 11.10.0 g.3gpp.ti This feature-capability indicator when used in a Feature-Caps header field as specified in IETF in SIP INVITE request or SIP response to the SIP INVITE request indicates the capability of associating a CS call with dialog created by the SIP INVITE request. 3GPP TS 24.237 11.10.0 g.3gpp.loopback This feature-capability indicator, when included in a Feature-Caps header field as specified in in a SIP INVITE request, indicates the support of the roaming architecture for voice over IMS with local breakout. 3GPP TS 24.229 g.3gpp.trf This feature-capability indicator, when included in a Feature-Caps header field as specified in in a SIP INVITE request, indicates that in a roaming scenario, the visited network supports a transit and roaming functionality in order to allow loopback of session requests to the visited network from the home network. When used, it may indicate the URI of the transit and roaming functionality. 3GPP TS 24.229 11.11.0 g.3gpp.home-visited This feature-capability indicator, when included in a Feature-Caps header field as specified in in a SIP INVITE request, indicates that the home network supports loopback to the identified visited network for this session. The loopback is expected to be applied at some subsequent entity to the insertion point. The feature-capability indicator carries a parameter value which indicates the visited network. 3GPP TS 24.229 g.3gpp.mrb This feature-capability indicator when included in a Feature-Caps header field as specified in in a SIP INVITE request indicates that in a roaming scenario, the visited network supports media resource broker functionality for the allocation of multimedia resources in the visited network. When used, it indicates the URI of the visited network MRB. 3GPP TS 24.229 11.11.0 g.3gpp.icsi-ref Each value of the Service Reference feature-capability indicator indicates the software applications supported by the entity. The values for this feature-capability indicator equal the IMS communication Service Identifier (ICSI) values supported by the entity. Multiple feature-capability indicator values can be included in the Service Reference feature-capability indicators. When included in the Feature-Caps header field, according to , the value of this feature-capability indicator contains the IMS communication service identifier (ICSI) of the IMS communication service supported for use 1) in the standalone transaction (if included in a request for a standalone transaction or a response associated with it) or 2) in the dialog (if included in an initial request for dialog or a response associated with it) by the entity which included the Feature-Caps header field. 3GPP TS 24.229 11.12.0 g.3gpp.drvcc-alerting This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP INVITE request or a SIP response to the SIP INVITE request indicates support of PS to CS dual radio access transfer for calls in alerting phase. 3GPP TS 24.237 12.8.0 g.3gpp.dynamic-stn This feature-capability indicator g.3gpp.dynamic-stn, when included in a Feature-Caps header field as specified in IETF in a SIP INVITE request or a SIP response to the SIP INVITE request, indicates support to transfer the session to the circuit switched (CS) domain using the dynamic STN (session transfer number) digit string. 3GPP TS 24.237 12.8.0 g.3gpp.ps2cs-drvcc-orig-pre-alerting This feature-capability indicator g.3gpp.ps2cs-srvcc-orig-pre-alerting when used in a Feature-Caps header field of a SIP request or a SIP response indicates that: 1. the functional entity including the feature-capability indicator in the SIP message supports the PS to CS SRVCC for originating calls in pre-alerting phase; and 2. all entities of which the functional entity including the feature-capability indicator in the SIP message is aware of being requested to support the feature do support the PS to CS SRVCC for originating calls in pre-alerting phase. 3GPP TS 24.237 12.8.0 g.3gpp.ps2cs-srvcc-orig-pre-alerting This feature-capability indicator g.3gpp.ps2cs-srvcc-orig-pre-alerting when used in a Feature-Caps header field of a SIP request or a SIP response indicates that: 1. the functional entity including the feature-capability indicator in the SIP message supports the PS to CS SRVCC for originating calls in pre-alerting phase; and 2. all entities of which the functional entity including the feature-capability indicator in the SIP message is aware of being requested to support the feature do support the PS to CS SRVCC for originating calls in pre-alerting phase. 3GPP TS 24.237 12.8.0 g.3gpp.cs2ps-drvcc-alerting This feature-capability indicator, when included in a Feature-Caps header field as specified in IETF in a SIP request or a SIP response to the SIP request, indicates support of CS to PS dual radio access transfer for calls in alerting phase. 3GPP TS 24.237 12.9.0 g.3gpp.cs2ps-drvcc-orig-pre-alerting This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP request or a SIP response to the SIP request indicates support of CS to PS dual radio access transfer for originating calls in pre-alerting phase. 3GPP TS 24.237 12.9.0 g.3gpp.ics This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP initial request for dialog or a response associated with the SIP initial request indicates support of IMS Centralized Services (ICS). 3GPP TS 24.292 12.8.0 g.3gpp.registration-token This feature-capability indicator, when included in a Feature-Caps header field as specified in [190] in a SIP REGISTER request, indicates the support of using a token to identify the registration used for the request. This feature-capability indicator can be included in an originating initial INVITE request to identify which registration was used for this request by setting the indicator to the same value as in the +g.3gpp.registration-token media feature tag in the Contact header field of the REGISTER request. This feature-capability indicator can be included in any response to a terminating INVITE request to identify which registration was used for the response by setting the indicator to the same value as in the +g.3gpp.registration-token media feature tag in the Contact header field of the REGISTER request. 3GPP TS 24.229 12.16.0 g.3gpp.verstat This feature-capability indicator, when included in a Feature-Caps header field as specified in in a 200 (OK) response to a REGISTER request, indicates that the home network supports calling party number verification, as described in . 3GPP TS 24.229 v14.7.0 g.3gpp.mcvideo.ambient-viewing-call-release This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP INVITE request or a SIP 200 (OK) response to a SIP INVITE request indicates that the MCVideo server is capable of receiving a SIP BYE from an MCVideo client to release an ambient-viewing call. 3GPP TS 24.281 Rel-15 g.3gpp.mcptt.ambient-listening-call-release This feature-capability indicator when included in a Feature-Caps header field as specified in IETF in a SIP INVITE request or a SIP 200 (OK) response to a SIP INVITE request indicates that the MCPTT server is capable of receiving a SIP BYE from an MCPTT client to release an ambient-listening call. 3GPP TS 24.379 v14.5.0 g.3gpp.dynamic-e-stn-drvcc This feature-capability indicator, when included in a Feature-Caps header field as specified in IETF in a SIP response to a SIP INVITE request, indicates support to transfer the session to the circuit switched (CS) domain using the Emergency Session Transfer Number for DRVCC digit string. 3GPP TS 24.237 g.3gpp.ps2cs-srvcc-term-pre-alerting This feature-capability indicator when used in a Feature-Caps header field of a SIP request or a SIP response indicates that: 1. the functional entity including the feature-capability indicator in the SIP message supports the PS to CS SRVCC for terminating calls in pre-alerting phase; and 2. all entities of which the functional entity including the feature-capability indicator in the SIP message is aware of being requested to support the feature do support the PS to CS SRVCC for terminating calls in pre-alerting phase. 3GPP TS 24.237 g.3gpp.priority-share When included in a Feature-Caps header field in SIP requests or SIP responses, the sender indicates that priority sharing is supported. 3GPP TS 24.229 13.16.0 g.3gpp.thig-path This feature-capability indicator when included in a Feature-Caps header field as specified in in a 200 (OK) response to the REGISTER request indicates that in a roaming scenario, the visited network IBCF supports topology hiding of a Path header field. 3GPP TS 24.229 g.3gpp.anbr This feature-capability indicator, when included in a Feature-Caps header field as specified in in a 200 (OK) response to a REGISTER request, indicates that the network supports ANBR as specified in 3GPP TS 26.114. 3GPP TS 24.229 g.3gpp.in-call-access-update This feature-capability indicator, when included in a Feature-Caps header field as specified in in a SIP INVITE request or a response to a SIP INVITE, indicates that the entity supports in-call access update procedure specified in 3GPP TS 24.229. The value of this feature capability indicator is a SIP URI to where the entity can be reached. 3GPP TS 24.229 g.3gpp.datachannel This feature-capability indicator indicates the support of data channel capability in the network, and can be included in a Feature-Caps header field as specified in in a 200 (OK) response to the REGISTER request. 3GPP TS 24.186 g.3gpp.dc-mux This feature-capability indicator indicates the support of IMS data channel multiplexing capability in the network, and can be included in a Feature-Caps header field as specified in in SIP request and response. 3GPP TS 24.186 IETF Review sip.607 This feature-capability indicator, when included in a Feature-Caps header field of a REGISTER response, indicates that the server supports, and will process, the 607 (Unwanted) response code. sip.pns This feature-capability indicator, when inserted in a Feature-Caps header field of a SIP REGISTER request or a SIP 2xx response to a REGISTER request, denotes that the entity associated with the indicator supports the SIP push mechanism and the type of push notification service conveyed by the indicator value. sip.vapid This feature-capability indicator, when inserted in a SIP 2xx response to a SIP REGISTER request, denotes that the entity associated with the indicator supports the Voluntary Application Server Identification (VAPID) mechanism when the entity requests that a push notification be sent to a SIP UA. The indicator value is a public key identifying the entity, which can be used by a SIP UA to restrict subscriptions to that entity. sip.pnsreg This feature-capability indicator, when inserted in a SIP 2xx response to a SIP REGISTER request, denotes that the entity associated with the indicator expects to receive binding-refresh REGISTER requests for the binding from the SIP UA associated with the binding before the binding expires, even if the entity does not request that a push notification be sent to the SIP UA in order to trigger the binding-refresh REGISTER requests. The indicator value conveys the minimum time (given in seconds) prior to the binding expiration when the UA MUST send the REGISTER request. sip.pnspurr This feature-capability indicator, when inserted in a SIP 2xx response to a SIP REGISTER request, conveys that the entity associated with the indicator will store information that can be used to associate a mid-dialog SIP request with the binding information in the REGISTER request. The indicator value is an identifier that can be used as a key to retrieve the binding information. sip.608 This feature-capability indicator, when included in a Feature-Caps header field of an INVITE request, indicates that the entity associated with the indicator will be responsible for indicating to the caller any information contained in the 608 SIP response code, specifically, the value referenced by the Call-Info header. IETF Review non-urgent normal urgent emergency psap-callback Standards Action UDP TCP TLS SCTP TLS-SCTP WS WSS Standards Action UUI packages provide information about the usage of the UUI data in a User-to-User header field . isdn-uui The associated application is being used with constraints suitable for interworking with the ISDN User-to-User service, and therefore can be interworked at ISDN gateways. Standards Action UUI content provides information about the content of the UUI data in a User-to-User header field . isdn-uui The associated contents conforms to the content associated with the ISDN User-to-User service. In the presence of the "purpose" header field parameter set to "isdn-uui" (or the absence of any "purpose" header field parameter) this is the default meaning and therefore need not be included in this case. Standards Action UUI encoding provides information about the encoding of the UUI data in a User-to-User header field . hex The UUI data is encoded using hexadecimal Specification Required Christer Holmberg apns Apple Push Notification service fcm Firebase Cloud Messaging webpush Generic Event Delivery Using HTTP Push Specification Required Brian Rosen 100 "Cannot process the alert payload" 101 "Alert payload was not present or could not be found" 102 "Not enough information to determine the purpose of the alert" 103 "Alert payload was corrupted" 3GPP Specifications Manager mailto:3gppContact&etsi.org 2023-07-31 Adam Roach mailto:adam&nostrum.com 2013-02-26 Cullen Jennings mailto:fluffy&cisco.com Dongwook Kim mailto:dongwook.kim&etsi.org 2026-01-15 Jon Peterson mailto:jon.peterson&neustar.biz Lionel Morand mailto:lionel.morand&orange.com 2023-03-13 Mary Barnes mailto:mary.ietf.barnes&gmail.com 2013-06-18