javax.sip

Class Timeout

java.lang.Object

javax.sip.Timeout

All Implemented Interfaces:

Serializable

public final class Timeout
extends Object
implements Serializable

This class contains the enumerations that define whether a timeout has occured in the underlying implementation. The application gets informed on whether a retransmission or transaction timer has expired. There are two types of Timeout, namely:

• RETRANSMIT - This type is used to alert an application that the underlying retransmit timer has expired so an application can resend the message specific to a transaction. This timer is defaulted to 500ms and is doubled each time it is fired until the transaction expires TRANSACTION. The default retransmission value can be changed per transaction using Transaction.setRetransmitTimer(int). The RETRANSMIT type is exposed to the following applications as follows:
  • User Agent - Retransmissions on Invite transactions are the responsibility of the application. This is due to the three way handshake for an INVITE Request. All other retransmissions are handled by the underlying implementation. Therefore the application will only receive this Timeout type specific to Invite transactions.
  • User Agent with No Retransmission - an application can configure an implementation to handle all retransmissions using property characteristics of the SipStack. Therefore a Timeout of this type will not be passed to the application. The application will only get notified when the TRANSACTION occurs.
  • Stateful Proxy - a stateful proxy remembers transaction state about each incoming request and any requests it sends as a result of processing the incoming request. The underlying implementation will handle the retransmissions of all messages it sends and the application will not receive RETRANSMIT events, however the application will get notified of TRANSACTION events. As an Invite transaction is end to end a stateful proxy will not handle the retransmissions of messages on an Invite transaction, unless it decides to respond to the Invite transaction, in essence becoming an User Agent Server and as such should behave as described by the User Agent semantics above bearing in mind the retranmission property of the underlying implementation.
  • Stateless Proxy - as a stateless proxy acts as a simple forwarding agent, i.e. it simply forwards every message it receives upstream, it keeps no transaction state for messages. The implementation does not retransmit messages, therefore an application will not receive RETRANSMIT events on a message handled statelessly. If retransmission semantics are required by an application using a stateless method, it is the responsibility of the application to provide this feature, not the underlying implementation.
• TRANSACTION - This type is used to alert an application that the underlying transaction has expired. A transaction timeout typically occurs at a time 64*T1 were T1 is the initial value of the RETRANSMIT, usually defaulted to 500ms. The TRANSACTION type is exposed to the following applications as follows:
  • User Agent - All retransmissions except retransmissions on Invite transactions are the responsibility of the underlying implementation, i.e. Invite transactions are the responsibility of the application. Therefore the application will only recieve TRANSACTION Timeout events on transactions that are not Invite transactions.
  • User Agent with No Retransmission - an application can configure an implementation to handle all retransmissions using property characteristics of the SipStack. Therefore a TRANSACTION Timeout will be fired to the application on any transaction that expires including an Invite transaction.
  • Stateful Proxy - a stateful proxy remembers transaction state about each incoming request and any requests it sends as a result of processing the incoming request. The underlying implementation handles the retransmissions of all messages it sends and will notify the application of TRANSACTION events on any of its transactions. As an Invite transaction is end to end a stateful proxy will not handle transaction timeouts on an Invite transaction, unless it decides to respond to the Invite transaction, in essence becoming an User Agent Server and as such should behave as described by the User Agent semantics above bearing in mind the retransmission property of the underlying implementation.
  • Stateless Proxy - as a stateless proxy acts as a simple forwarding agent, i.e. it simply forwards every message it receives upstream, it keeps no transaction state of the messages. The implementation does not maintain transaction state, therefore an application will not receive TRANSACTION events on a message handled statelessly. If transaction timeout semantics are required by an application using a stateless method, it the responsibility of the application to provide this feature, not the underlying implementation.

Version:

1.2

Author:

BEA Systems, NIST

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static int	_RETRANSMIT This constant value indicates the internal value of the Retransmit timeout.
static int	_TRANSACTION This constant value indicates the internal value of the Transaction timeout.
static Timeout	RETRANSMIT This constant value indicates the "Retransmit" timeout.
static Timeout	TRANSACTION This constant value indicates the "Transaction" timeout.

Method Summary

Methods

Modifier and Type	Method and Description
Timeout	getObject(int timeout) This method returns the object value of the Timeout
int	getValue() This method returns the integer value of the Timeout
String	toString() This method returns a string version of this class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

_RETRANSMIT

public static final int _RETRANSMIT

This constant value indicates the internal value of the Retransmit timeout.
This constant has an integer value of 0.

See Also:

Constant Field Values

RETRANSMIT

public static final Timeout RETRANSMIT

This constant value indicates the "Retransmit" timeout.

_TRANSACTION

public static final int _TRANSACTION

This constant value indicates the internal value of the Transaction timeout.
This constant has an integer value of 1.

See Also:

Constant Field Values

TRANSACTION

public static final Timeout TRANSACTION

This constant value indicates the "Transaction" timeout.

Method Detail

getObject

public Timeout getObject(int timeout)

This method returns the object value of the Timeout

Parameters:

timeout - The integer value of the Timeout

Returns:

The Timeout Object

getValue

public int getValue()

This method returns the integer value of the Timeout

Returns:

The integer value of the Timeout

toString

public String toString()

This method returns a string version of this class.

Overrides:

toString in class Object

Returns:

The string version of the Timeout