android.gov.nist.javax.sip.header.extensions.JoinHeader Maven / Gradle / Ivy
/*
* Conditions Of Use
*
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain. As a result, a formal
* license is not needed to use the software.
*
* This software is provided by NIST as a service and is expressly
* provided "AS IS." NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY. NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
*
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*
* .
*
*/
package android.gov.nist.javax.sip.header.extensions;
import java.text.ParseException;
import android.javax.sip.header.Header;
import android.javax.sip.header.Parameters;
/**
* The From header field indicates the logical identity of the initiator
* of the request, possibly the user's address-of-record. This may be different
* from the initiator of the dialog. Requests sent by the callee to the caller
* use the callee's address in the From header field.
*
* Like the To header field, it contains a URI and optionally a display name,
* encapsulated in a {@link android.javax.sip.address.Address}. It is used by SIP
* elements to determine which processing rules to apply to a request (for
* example, automatic call rejection). As such, it is very important that the
* From URI not contain IP addresses or the FQDN of the host on which the UA is
* running, since these are not logical names.
*
* The From header field allows for a display name. A UAC SHOULD use
* the display name "Anonymous", along with a syntactically correct, but
* otherwise meaningless URI (like sip:[email protected]), if the
* identity of the client is to remain hidden.
*
* Usually, the value that populates the From header field in requests
* generated by a particular UA is pre-provisioned by the user or by the
* administrators of the user's local domain. If a particular UA is used by
* multiple users, it might have switchable profiles that include a URI
* corresponding to the identity of the profiled user. Recipients of requests
* can authenticate the originator of a request in order to ascertain that
* they are who their From header field claims they are.
*
* Two From header fields are equivalent if their URIs match, and their
* parameters match. Extension parameters in one header field, not present in
* the other are ignored for the purposes of comparison. This means that the
* display name and presence or absence of angle brackets do not affect
* matching.
*
* - The "Tag" parameter - is used in the To and From header fields of SIP
* messages. It serves as a general mechanism to identify a dialog, which is
* the combination of the Call-ID along with two tags, one from each
* participant in the dialog. When a User Agent sends a request outside of a dialog,
* it contains a From tag only, providing "half" of the dialog ID. The dialog
* is completed from the response(s), each of which contributes the second half
* in the To header field. When a tag is generated by a User Agent for insertion into
* a request or response, it MUST be globally unique and cryptographically
* random with at least 32 bits of randomness. Besides the requirement for
* global uniqueness, the algorithm for generating a tag is implementation
* specific. Tags are helpful in fault tolerant systems, where a dialog is to
* be recovered on an alternate server after a failure. A UAS can select the
* tag in such a way that a backup can recognize a request as part of a dialog
* on the failed server, and therefore determine that it should attempt to
* recover the dialog and any other state associated with it.
*
* For Example:
* From: "Bob" sips:[email protected] ;tag=a48s
* From: sip:[email protected];tag=887s
* From: Anonymous sip:[email protected];tag=hyh8
*
* @version 1.1
* @author [email protected]
*/
public interface JoinHeader extends Parameters, Header {
/**
* Sets the tag parameter of the FromHeader. The tag in the From field of a
* request identifies the peer of the dialog. When a UA sends a request
* outside of a dialog, it contains a From tag only, providing "half" of
* the dialog Identifier.
*
* The From Header MUST contain a new "tag" parameter, chosen by the UAC
* applicaton. Once the initial From "tag" is assigned it should not be
* manipulated by the application. That is on the client side for outbound
* requests the application is responsible for Tag assigmennment, after
* dialog establishment the stack will take care of Tag assignment.
*
* @param tag - the new tag of the FromHeader
* @throws ParseException which signals that an error has been reached
* unexpectedly while parsing the Tag value.
*/
public void setToTag(String tag) throws ParseException;
public void setFromTag(String tag) throws ParseException;
/**
* Gets the tag of FromHeader. The Tag parameter identified the Peer of the
* dialogue and must always be present.
*
* @return the tag parameter of the FromHeader.
*/
public String getToTag();
public String getFromTag();
/**
* Sets the Call-Id of the CallIdHeader. The CallId parameter uniquely
* identifies a serious of messages within a dialogue.
*
* @param callId - the string value of the Call-Id of this CallIdHeader.
* @throws ParseException which signals that an error has been reached
* unexpectedly while parsing the callId value.
*/
public void setCallId(String callId) throws ParseException;
/**
* Returns the Call-Id of CallIdHeader. The CallId parameter uniquely
* identifies a series of messages within a dialogue.
*
* @return the String value of the Call-Id of this CallIdHeader
*/
public String getCallId();
/**
* Name of JoinHeader
*/
public final static String NAME = "Join";
}