November 2006

Interface MinExpiresHeader

All Superinterfaces:
java.lang.Cloneable, ExpiresHeader, Header, java.io.Serializable

public interface MinExpiresHeader
extends ExpiresHeader

The Min-Expires header field conveys the minimum refresh interval supported for soft-state elements managed by that server. This includes Contact header fields that are stored by a registrar. The header field contains a decimal integer number of seconds from 0 to (2**32)-1.

Allowing the registrar to set the registration interval protects it against excessively frequent registration refreshes while limiting the state that it needs to maintain and decreasing the likelihood of registrations going stale. The expiration interval of a registration is frequently used in the creation of services. An example is a follow-me service, where the user may only be available at a terminal for a brief period. Therefore, registrars should accept brief registrations; a request should only be rejected if the interval is so short that the refreshes would degrade registrar performance.

If a User Agent receives a 423 (Interval Too Brief) response to a REGISTER request, it MAY retry the registration after making the expiration interval of all contact addresses in the REGISTER request equal to or greater than the expiration interval within the Min-Expires header field of the 423 (Interval Too Brief) response. The Min-Expires header field that states the minimum expiration interval the registrar is willing to honor.

For Example:
Min-Expires: 60

BEA Systems, NIST

Field Summary
static java.lang.String NAME
          Name of ExpiresHeader
Method Summary
Methods inherited from interface javax.sip.header.ExpiresHeader
getExpires, setExpires
Methods inherited from interface javax.sip.header.Header
clone, equals, getName, hashCode, toString

Field Detail


static final java.lang.String NAME
Name of ExpiresHeader

See Also:
Constant Field Values

November 2006

If you have any comments, please mail them to JAIN-SIP-INTEREST@java.sun.com after subscribing at http://archives.java.sun.com
Copyright - 2006 BEA Systems and Sun Microsystems