/**
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Unpublished - rights reserved under the Copyright Laws of the United States.
* Copyright � 2003 Sun Microsystems, Inc. All rights reserved.
* Copyright � 2005 BEA Systems, Inc. All rights reserved.
*
* Use is subject to license terms.
*
* This distribution may include materials developed by third parties.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Module Name : JSIP Specification
* File Name : Response.java
* Author : Phelim O'Doherty
*
* HISTORY
* Version Date Author Comments
* 1.1 08/10/2002 Phelim O'Doherty Initial version
*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
package javax.sip.message;
import java.text.ParseException;
/**
* A Response message is sent by a recipient of Request once it has received
* and interpreted the Request. Responses are contain a Status-Code and a
* Reason-Phrase, as well as Headers and a possible message body.
* <p>
* The Status-Code is a 3-digit integer result code that indicates the
* outcome of the attempt to understand and satisfy the Request. The
* Reason-Phrase is intended to give a short textual description of the
* Status-Code. The Status-Code is intended for use by automata, whereas
* the Reason-Phrase is intended for the human user. The client is not
* required to examine or display the Reason-Phrase.
* <p>
* RFC3261 defines status codes in the following classes:
* <ul>
* <li><b>1xx: Provisional</b> -- request received, continuing to process the request;
* Provisional responses, also known as informational responses, indicate that
* the server contacted is performing some further action and does not yet have
* a definitive response.
* <ul>
* <li> This specification also supports the delivery of reliable provisional responses as defined in
* <a href = "http://www.ietf.org/rfc/rfc3262.txt">RFC 3262</a>. When
* the UAC creates a new request, it can insist on reliable delivery of
* provisional responses for that request. To do that, it inserts a Require
* header field with the option tag 100rel into the request. A Require header
* with the value <code>100rel</code> MUST NOT be present in any requests excepting INVITE,
* although other extensions to SIP may allow its usage with other request
* methods. If the UAC does not wish to insist on usage of reliable provisional
* responses, but merely indicate that it supports them if the UAS needs to send
* one, a Supported header MUST be included in the request with the option tag
* <code>100rel</code>. The UAC SHOULD include this in all INVITE requests.
* <p>
* A UAS MAY send any non-100 provisional response to INVITE reliably, so long
* as the initial INVITE request (the request whose provisional response is
* being sent reliably) contained a Supported header field with the option tag
* <code>100rel</code>. The provisional response to be sent reliably is
* constructed by the UAS and MUST contain a Require header field containing
* the option tag <code>100rel</code>, and MUST include an RSeq header field.
* Retransmissions of the reliable provisional response cease when a
* matching PRACK is received by the UA core. PRACK is like any other request
* within a dialog, and is treated likewise. A matching PRACK is defined as one
* within the same dialog as the response, and whose method, CSeq-num, and
* RSeq-num in the RAck header field match, respectively, the method and
* sequence number from the CSeq and the sequence number from the RSeq of the
* reliable provisional response.
* </ul>
* <li><b>2xx: Success</b> -- the action was successfully received, understood, and
* accepted.
* <li><b>3xx: Redirection</b> -- further action needs to be taken in order to
* complete the request; 3xx responses give information about the user's new
* location, or about alternative services that might be able to satisfy the call.
* <li><b>4xx: Client Error</b> -- the request contains bad syntax or cannot be
* fulfilled at this server; 4xx responses are definite failure responses from
* a particular server. The client SHOULD NOT retry the same request without
* modification. However, the same request to a different server might be
* successful.
* <li><b>5xx: Server Error</b> -- the server failed to fulfill an apparently valid
* request; 5xx responses are failure responses given when a server itself has
* erred.
* <li><b>6xx: Global Failure</b> -- the request cannot be fulfilled at any server;
* 6xx responses indicate that a server has definitive information about a
* particular user, not just the particular instance indicated in the Request-URI.
* </ul>
* SIP status codes are extensible. The response codes are consistent with, and
* extend, <a href = "http://www.ietf.org/rfc/rfc2616.txt">HTTP/1.1</a> response codes. Not all HTTP/1.1 response codes are
* appropriate, and only those that are appropriate are given here. Other
* HTTP/1.1 response codes SHOULD NOT be used. Also, SIP defines a new class,
* 6xx.
* <p>
* SIP applications are not required to understand the meaning of all
* registered response codes, though such understanding is obviously desirable.
* However, applications must understand the class of any status code, as
* indicated by the first digit and outlined above. Applications treat any
* unrecognized status code as being equivalent to the x00 status code of that
* class, with the exception that an unrecognized status code must not be
* cached. For example, if a client receives an unrecognized status code of 431,
* it can safely assume that there was something wrong with its request and
* treat the Response as if it had received a BAD_REQUEST(400) status code. In
* such cases, user agents should present to the user the message body returned
* with the Response, since that message body is likely to include
* human-readable information which will explain the unusual status.
* <p>
* This specification supports the response codes defined in RFC3261 and also the response
* code extensions for the event notification framework and PUBLISH, documented in
* <a href = "http://www.ietf.org/rfc/rfc3262.txt">RFC3265</a> and
* <a href = "http://www.ietf.org/rfc/rfc3909.txt">RFC3909</a>, these are
* highlighted in italic. Class status codes (x00, i.e. 100) are are highlighted
* in bold.
* </p>
* <table BORDER WIDTH="75%" >
* <tr>
* <td><b>Class</b></td>
* <td><b>Code</b></td>
* </tr>
* <tr>
* <td>PROVISIONAL (1xx)</td>
* <td>
* <LI><b>TRYING - 100</b></LI>
* <LI>RINGING - 180</LI>
* <LI>CALL_IS_BEING_FORWARDED - 181</LI>
* <LI>QUEUED - 182</LI>
* <li>SESSION_PROGRESS - 183</li>
* </td>
* </tr>
* <tr>
* <td>SUCCESS (2xx)</td>
* <td>
* <LI><b>OK - 200</b></LI>
* <LI><i>ACCEPTED - 202 (Extension RFC3265)</i></LI>
* </td>
* </tr>
* <tr>
* <td>REDIRECTION (3xx)</td>
* <td>
* <LI><b>MULTIPLE_CHOICES - 300</b></LI>
* <LI>MOVED_PERMANENTLY - 301</LI>
* <LI>MOVED_TEMPORARILY - 302</LI>
* <LI>USE_PROXY - 305</LI>
* <LI>ALTERNATIVE_SERVICE - 380</LI>
* </td>
* </tr>
* <tr>
* <td>CLIENT_ERROR (4xx)</td>
* <td>
* <LI><b>BAD_REQUEST - 400</b></LI>
* <LI>UNAUTHORIZED - 401</LI>
* <LI>PAYMENT_REQUIRED - 402</LI>
* <LI>FORBIDDEN - 403</LI>
* <LI>NOT_FOUND - 404</LI>
* <LI>METHOD_NOT_ALLOWED - 405</LI>
* <LI>NOT_ACCEPTABLE - 406</LI>
* <LI>PROXY_AUTHENTICATION_REQUIRED - 407</LI>
* <LI>REQUEST_TIMEOUT - 408</LI>
* <LI>GONE - 410</LI>
* <LI><i>CONDITIONAL_REQUEST_FAILED - 412 (Extension RFC3909)<i>
* <LI>REQUEST_ENTITY_TOO_LARGE - 413
* <LI>REQUEST_URI_TOO_LONG - 414
* <LI>UNSUPPORTED_MEDIA_TYPE - 415</LI>
* <LI>UNSUPPORTED_URI_SCHEME - 416
* <LI>BAD_EXTENSION - 420</LI>
* <LI>EXTENSION_REQUIRED - 421
* <LI>INTERVAL_TOO_BRIEF - 423
* <LI>TEMPORARILY_UNAVAILABLE - 480</LI>
* <LI>CALL_OR_TRANSACTION_DOES_NOT_EXIST - 481</LI>
* <LI>LOOP_DETECTED - 482</LI>
* <LI>TOO_MANY_HOPS - 483</LI>
* <LI>ADDRESS_INCOMPLETE - 484</LI>
* <LI>AMBIGUOUS - 485</LI>
* <LI>BUSY_HERE - 486</LI>
* <LI>REQUEST_TERMINATED - 487
* <LI>NOT_ACCEPTABLE_HERE - 488
* <LI><i>BAD EVENT - 489 (Extension RFC3265)<i></LI>
* <LI>REQUEST_PENDING - 491
* <LI>UNDECIPHERABLE - 493
* </td>
* </tr>
* <tr>
* <td>SERVER_ERROR (5xx)</td>
* <td>
* <LI><b>SERVER_INTERNAL_ERROR - 500</b></LI>
* <LI>NOT_IMPLEMENTED - 501</LI>
* <LI>BAD_GATEWAY - 502</LI>
* <LI>SERVICE_UNAVAILABLE - 503</LI>
* <LI>SERVER_TIMEOUT - 504</LI>
* <LI>VERSION_NOT_SUPPORTED - 505</LI>
* <LI>MESSAGE_TOO_LARGE - 513
* </td>
* </tr>
* <tr>
* <td>GLOBAL_ERROR (6xx)</td>
* <td>
* <LI><b>BUSY_EVERYWHERE - 600</b></LI>
* <LI>DECLINE - 603</LI>
* <LI>DOES_NOT_EXIST_ANYWHERE - 604</LI>
* <LI>SESSION_NOT_ACCEPTABLE - 606</LI>
* </td>
* </tr>
* </table>
*
* @author BEA Systems, NIST
* @version 1.2
*
*/
public interface Response extends Message {
/**
* Sets the status-code of Response. The status-code is a 3-digit integer
* result code that indicates the outcome of an attempt to understand and
* satisfy a request. The Status-Code is intended for use by automata.
*
* @param statusCode the new integer value of the status code.
* @throws ParseException which signals that an error has been reached
* unexpectedly while parsing the statusCode value.
*/
public void setStatusCode(int statusCode) throws ParseException;
/**
* Gets the integer value of the status code of Response, which identifies
* the outcome of the request to which this response is related.
*
* @return the integer status-code of this Response message.
*/
public int getStatusCode();
/**
* Sets reason phrase of Response. The reason-phrase is intended to give a
* short textual description of the status-code. The reason-phrase is
* intended for the human user. A client is not required to examine or
* display the reason-phrase. While RFC3261 suggests specific wording for
* the reason phrase, implementations MAY choose other text.
*
* @param reasonPhrase the new string value of the reason phrase.
* @throws ParseException which signals that an error has been reached
* unexpectedly while parsing the reasonPhrase value.
*/
public void setReasonPhrase(String reasonPhrase) throws ParseException;
/**
* Gets the reason phrase of this Response message.
*
* @return the string value of the reason phrase of this Response message.
*/
public String getReasonPhrase();
// Response status codes
/**
* This response indicates that the request has been received by the
* next-hop server and that some unspecified action is being taken on
* behalf of this call (for example, a database is being consulted). This
* response, like all other provisional responses, stops retransmissions of
* an INVITE by a UAC. The 100 (Trying) response is different from other
* provisional responses, in that it is never forwarded upstream by a
* stateful proxy.
*/
public static final int TRYING = 100;
/**
* The User Agent receiving the INVITE is trying to alert the user. This
* response MAY be used to initiate local ringback.
*/
public static final int RINGING = 180;
/**
* A server MAY use this status code to indicate that the call is being
* forwarded to a different set of destinations.
*/
public static final int CALL_IS_BEING_FORWARDED = 181;
/**
* The called party is temporarily unavailable, but the server has decided
* to queue the call rather than reject it. When the callee becomes
* available, it will return the appropriate final status response. The
* reason phrase MAY give further details about the status of the call,
* for example, "5 calls queued; expected waiting time is 15 minutes". The
* server MAY issue several 182 (Queued) responses to update the caller
* about the status of the queued call.
*/
public static final int QUEUED = 182;
/**
* The 183 (Session Progress) response is used to convey information about
* the progress of the call that is not otherwise classified. The
* Reason-Phrase, header fields, or message body MAY be used to convey more
* details about the call progress.
*/
public static final int SESSION_PROGRESS = 183;
/**
* The request has succeeded. The information returned with the response
* depends on the method used in the request.
*/
public static final int OK = 200;
/**
* The Acceptable extension response code signifies that the request has
* been accepted for processing, but the processing has not been completed.
* The request might or might not eventually be acted upon, as it might be
* disallowed when processing actually takes place. There is no facility
* for re-sending a status code from an asynchronous operation such as this.
* The 202 response is intentionally non-committal. Its purpose is to allow
* a server to accept a request for some other process (perhaps a
* batch-oriented process that is only run once per day) without requiring
* that the user agent's connection to the server persist until the process
* is completed. The entity returned with this response SHOULD include an
* indication of the request's current status and either a pointer to a
* status monitor or some estimate of when the user can expect the request
* to be fulfilled. This response code is specific to the event notification
* framework.
*/
public static final int ACCEPTED = 202;
/**
* The address in the request resolved to several choices, each with its
* own specific location, and the user (or UA) can select a preferred
* communication end point and redirect its request to that location.
* <p>
* The response MAY include a message body containing a list of resource
* characteristics and location(s) from which the user or UA can choose
* the one most appropriate, if allowed by the Accept request header field.
* However, no MIME types have been defined for this message body.
* <p>
* The choices SHOULD also be listed as Contact fields. Unlike HTTP, the
* SIP response MAY contain several Contact fields or a list of addresses
* in a Contact field. User Agents MAY use the Contact header field value
* for automatic redirection or MAY ask the user to confirm a choice.
* However, this specification does not define any standard for such
* automatic selection.
* <p>
* This status response is appropriate if the callee can be reached at
* several different locations and the server cannot or prefers not to
* proxy the request.
*/
public static final int MULTIPLE_CHOICES = 300;
/**
* The user can no longer be found at the address in the Request-URI, and
* the requesting client SHOULD retry at the new address given by the
* Contact header field. The requestor SHOULD update any local directories,
* address books, and user location caches with this new value and redirect
* future requests to the address(es) listed.
*/
public static final int MOVED_PERMANENTLY = 301;
/**
* The requesting client SHOULD retry the request at the new address(es)
* given by the Contact header field. The Request-URI of the new request
* uses the value of the Contact header field in the response.
* <p>
* The duration of the validity of the Contact URI can be indicated through
* an Expires header field or an expires parameter in the Contact header
* field. Both proxies and User Agents MAY cache this URI for the duration
* of the expiration time. If there is no explicit expiration time, the
* address is only valid once for recursing, and MUST NOT be cached for
* future transactions.
* <p>
* If the URI cached from the Contact header field fails, the Request-URI
* from the redirected request MAY be tried again a single time. The
* temporary URI may have become out-of-date sooner than the expiration
* time, and a new temporary URI may be available.
*/
public static final int MOVED_TEMPORARILY = 302;
/**
* The requested resource MUST be accessed through the proxy given by the
* Contact field. The Contact field gives the URI of the proxy. The
* recipient is expected to repeat this single request via the proxy.
* 305 (Use Proxy) responses MUST only be generated by UASs.
*/
public static final int USE_PROXY = 305;
/**
* The call was not successful, but alternative services are possible. The
* alternative services are described in the message body of the response.
* Formats for such bodies are not defined here, and may be the subject of
* future standardization.
*/
public static final int ALTERNATIVE_SERVICE = 380;
/**
* The request could not be understood due to malformed syntax. The
* Reason-Phrase SHOULD identify the syntax problem in more detail, for
* example, "Missing Call-ID header field".
*/
public static final int BAD_REQUEST = 400;
/**
* The request requires user authentication. This response is issued by
* UASs and registrars, while 407 (Proxy Authentication Required) is used
* by proxy servers.
*/
public static final int UNAUTHORIZED = 401;
/**
* Reserved for future use.
*/
public static final int PAYMENT_REQUIRED = 402;
/**
* The server understood the request, but is refusing to fulfill it.
* Authorization will not help, and the request SHOULD NOT be repeated.
*/
public static final int FORBIDDEN = 403;
/**
* The server has definitive information that the user does not exist at
* the domain specified in the Request-URI. This status is also returned
* if the domain in the Request-URI does not match any of the domains
* handled by the recipient of the request.
*/
public static final int NOT_FOUND = 404;
/**
* The method specified in the Request-Line is understood, but not allowed
* for the address identified by the Request-URI. The response MUST include
* an Allow header field containing a list of valid methods for the
* indicated address
*/
public static final int METHOD_NOT_ALLOWED = 405;
/**
* The resource identified by the request is only capable of generating
* response entities that have content characteristics not acceptable
* according to the Accept header field sent in the request.
*/
public static final int NOT_ACCEPTABLE = 406;
/**
* This code is similar to 401 (Unauthorized), but indicates that the client
* MUST first authenticate itself with the proxy. This status code can be
* used for applications where access to the communication channel (for
* example, a telephony gateway) rather than the callee requires
* authentication.
*/
public static final int PROXY_AUTHENTICATION_REQUIRED = 407;
/**
* The server could not produce a response within a suitable amount of
* time, for example, if it could not determine the location of the user
* in time. The client MAY repeat the request without modifications at
* any later time.
*/
public static final int REQUEST_TIMEOUT = 408;
/**
* The requested resource is no longer available at the server and no
* forwarding address is known. This condition is expected to be considered
* permanent. If the server does not know, or has no facility to determine,
* whether or not the condition is permanent, the status code 404
* (Not Found) SHOULD be used instead.
*/
public static final int GONE = 410;
/**
* The server is refusing to service the PUBLISH request because the
* entity-tag in the SIP-If-Match header does not match with existing
* event state.
*
* @since v1.2
*/
public static final int CONDITIONAL_REQUEST_FAILED = 412;
/**
* The server is refusing to process a request because the request
* entity-body is larger than the server is willing or able to process. The
* server MAY close the connection to prevent the client from continuing
* the request. If the condition is temporary, the server SHOULD include a
* Retry-After header field to indicate that it is temporary and after what
* time the client MAY try again.
*/
public static final int REQUEST_ENTITY_TOO_LARGE = 413;
/**
* The server is refusing to service the request because the Request-URI
* is longer than the server is willing to interpret.
*/
public static final int REQUEST_URI_TOO_LONG = 414;
/**
* The server is refusing to service the request because the message body
* of the request is in a format not supported by the server for the
* requested method. The server MUST return a list of acceptable formats
* using the Accept, Accept-Encoding, or Accept-Language header field,
* depending on the specific problem with the content.
*/
public static final int UNSUPPORTED_MEDIA_TYPE = 415;
/**
* The server cannot process the request because the scheme of the URI in
* the Request-URI is unknown to the server.
*/
public static final int UNSUPPORTED_URI_SCHEME = 416;
/**
* The server did not understand the protocol extension specified in a
* Proxy-Require or Require header field. The server MUST include a list of
* the unsupported extensions in an Unsupported header field in the response.
*/
public static final int BAD_EXTENSION = 420;
/**
* The UAS needs a particular extension to process the request, but this
* extension is not listed in a Supported header field in the request.
* Responses with this status code MUST contain a Require header field
* listing the required extensions.
* <p>
* A UAS SHOULD NOT use this response unless it truly cannot provide any
* useful service to the client. Instead, if a desirable extension is not
* listed in the Supported header field, servers SHOULD process the request
* using baseline SIP capabilities and any extensions supported by the
* client.
*/
public static final int EXTENSION_REQUIRED = 421;
/**
* The server is rejecting the request because the expiration time of the
* resource refreshed by the request is too short. This response can be
* used by a registrar to reject a registration whose Contact header field
* expiration time was too small.
*/
public static final int INTERVAL_TOO_BRIEF = 423;
/**
* The callee's end system was contacted successfully but the callee is
* currently unavailable (for example, is not logged in, logged in but in a
* state that precludes communication with the callee, or has activated the
* "do not disturb" feature). The response MAY indicate a better time to
* call in the Retry-After header field. The user could also be available
* elsewhere (unbeknownst to this server). The reason phrase SHOULD indicate
* a more precise cause as to why the callee is unavailable. This value
* SHOULD be settable by the UA. Status 486 (Busy Here) MAY be used to more
* precisely indicate a particular reason for the call failure.
* <p>
* This status is also returned by a redirect or proxy server that
* recognizes the user identified by the Request-URI, but does not currently
* have a valid forwarding location for that user.
*/
public static final int TEMPORARILY_UNAVAILABLE = 480;
/**
* This status indicates that the UAS received a request that does not
* match any existing dialog or transaction.
*/
public static final int CALL_OR_TRANSACTION_DOES_NOT_EXIST = 481;
/**
* The server has detected a loop.
*/
public static final int LOOP_DETECTED = 482;
/**
* The server received a request that contains a Max-Forwards header field
* with the value zero.
*/
public static final int TOO_MANY_HOPS = 483;
/**
* The server received a request with a Request-URI that was incomplete.
* Additional information SHOULD be provided in the reason phrase. This
* status code allows overlapped dialing. With overlapped dialing, the
* client does not know the length of the dialing string. It sends strings
* of increasing lengths, prompting the user for more input, until it no
* longer receives a 484 (Address Incomplete) status response.
*/
public static final int ADDRESS_INCOMPLETE = 484;
/**
* The Request-URI was ambiguous. The response MAY contain a listing of
* possible unambiguous addresses in Contact header fields. Revealing
* alternatives can infringe on privacy of the user or the organization.
* It MUST be possible to configure a server to respond with status 404
* (Not Found) or to suppress the listing of possible choices for ambiguous
* Request-URIs. Some email and voice mail systems provide this
* functionality. A status code separate from 3xx is used since the
* semantics are different: for 300, it is assumed that the same person or
* service will be reached by the choices provided. While an automated
* choice or sequential search makes sense for a 3xx response, user
* intervention is required for a 485 (Ambiguous) response.
*/
public static final int AMBIGUOUS = 485;
/**
* The callee's end system was contacted successfully, but the callee is
* currently not willing or able to take additional calls at this end
* system. The response MAY indicate a better time to call in the Retry-After
* header field. The user could also be available elsewhere, such as
* through a voice mail service. Status 600 (Busy Everywhere) SHOULD be
* used if the client knows that no other end system will be able to accept
* this call.
*/
public static final int BUSY_HERE = 486;
/**
* The request was terminated by a BYE or CANCEL request. This response is
* never returned for a CANCEL request itself.
*/
public static final int REQUEST_TERMINATED = 487;
/**
* The response has the same meaning as 606 (Not Acceptable), but only
* applies to the specific resource addressed by the Request-URI and the
* request may succeed elsewhere. A message body containing a description
* of media capabilities MAY be present in the response, which is formatted
* according to the Accept header field in the INVITE (or application/sdp
* if not present), the same as a message body in a 200 (OK) response to
* an OPTIONS request.
*/
public static final int NOT_ACCEPTABLE_HERE = 488;
/**
* The Bad Event extension response code is used to indicate that the
* server did not understand the event package specified in a "Event"
* header field. This response code is specific to the event notification
* framework.
*/
public static final int BAD_EVENT = 489;
/**
* The request was received by a UAS that had a pending request within
* the same dialog.
*/
public static final int REQUEST_PENDING = 491;
/**
* The request was received by a UAS that contained an encrypted MIME body
* for which the recipient does not possess or will not provide an
* appropriate decryption key. This response MAY have a single body
* containing an appropriate public key that should be used to encrypt MIME
* bodies sent to this UA.
*/
public static final int UNDECIPHERABLE = 493;
/**
* The server encountered an unexpected condition that prevented it from
* fulfilling the request. The client MAY display the specific error
* condition and MAY retry the request after several seconds. If the
* condition is temporary, the server MAY indicate when the client may
* retry the request using the Retry-After header field.
*/
public static final int SERVER_INTERNAL_ERROR = 500;
/**
* The server does not support the functionality required to fulfill the
* request. This is the appropriate response when a UAS does not recognize
* the request method and is not capable of supporting it for any user.
* Proxies forward all requests regardless of method. Note that a 405
* (Method Not Allowed) is sent when the server recognizes the request
* method, but that method is not allowed or supported.
*/
public static final int NOT_IMPLEMENTED = 501;
/**
* The server, while acting as a gateway or proxy, received an invalid
* response from the downstream server it accessed in attempting to
* fulfill the request.
*/
public static final int BAD_GATEWAY = 502;
/**
* The server is temporarily unable to process the request due to a
* temporary overloading or maintenance of the server. The server MAY
* indicate when the client should retry the request in a Retry-After
* header field. If no Retry-After is given, the client MUST act as if it
* had received a 500 (Server Internal Error) response.
* <p>
* A client (proxy or UAC) receiving a 503 (Service Unavailable) SHOULD
* attempt to forward the request to an alternate server. It SHOULD NOT
* forward any other requests to that server for the duration specified
* in the Retry-After header field, if present.
* <p>
* Servers MAY refuse the connection or drop the request instead of
* responding with 503 (Service Unavailable).
*/
public static final int SERVICE_UNAVAILABLE = 503;
/**
* The server did not receive a timely response from an external server
* it accessed in attempting to process the request. 408 (Request Timeout)
* should be used instead if there was no response within the
* period specified in the Expires header field from the upstream server.
*/
public static final int SERVER_TIMEOUT = 504;
/**
* The server does not support, or refuses to support, the SIP protocol
* version that was used in the request. The server is indicating that
* it is unable or unwilling to complete the request using the same major
* version as the client, other than with this error message.
*/
public static final int VERSION_NOT_SUPPORTED = 505;
/**
* The server was unable to process the request since the message length
* exceeded its capabilities.
*/
public static final int MESSAGE_TOO_LARGE = 513;
/**
* The callee's end system was contacted successfully but the callee is
* busy and does not wish to take the call at this time. The response
* MAY indicate a better time to call in the Retry-After header field.
* If the callee does not wish to reveal the reason for declining the call,
* the callee uses status code 603 (Decline) instead. This status response
* is returned only if the client knows that no other end point (such as a
* voice mail system) will answer the request. Otherwise, 486 (Busy Here)
* should be returned.
*/
public static final int BUSY_EVERYWHERE = 600;
/**
* The callee's machine was successfully contacted but the user explicitly
* does not wish to or cannot participate. The response MAY indicate a
* better time to call in the Retry-After header field. This status
* response is returned only if the client knows that no other end point
* will answer the request.
*/
public static final int DECLINE = 603;
/**
* The server has authoritative information that the user indicated in the
* Request-URI does not exist anywhere.
*/
public static final int DOES_NOT_EXIST_ANYWHERE = 604;
/**
* The user's agent was contacted successfully but some aspects of the
* session description such as the requested media, bandwidth, or addressing
* style were not acceptable. A 606 (Not Acceptable) response means that
* the user wishes to communicate, but cannot adequately support the
* session described. The 606 (Not Acceptable) response MAY contain a list
* of reasons in a Warning header field describing why the session described
* cannot be supported.
* <p>
* A message body containing a description of media capabilities MAY be
* present in the response, which is formatted according to the Accept
* header field in the INVITE (or application/sdp if not present), the same
* as a message body in a 200 (OK) response to an OPTIONS request.
* <p>
* It is hoped that negotiation will not frequently be needed, and when a
* new user is being invited to join an already existing conference,
* negotiation may not be possible. It is up to the invitation initiator to
* decide whether or not to act on a 606 (Not Acceptable) response.
* <p>
* This status response is returned only if the client knows that no other
* end point will answer the request. This specification renames this
* status code from NOT_ACCEPTABLE as in RFC3261 to SESSION_NOT_ACCEPTABLE
* due to it conflict with 406 (Not Acceptable) defined in this interface.
*/
public static final int SESSION_NOT_ACCEPTABLE = 606;
}