v1.1 - 23rd June 2003

JAINTM SIP API Specification v1.1

Final Release
The JAIN SIP API Specification v1.1 is the copyright of Sun Microsystems

This document specifies the JAINTM SIP API Specification v1.1.


javax.sip This package contains the main interfaces that model the JAIN SIP architectute from both an application developer and a stack vendor view.
javax.sip.address This package contains interfaces that represent the Addressing components of the SIP protocol.
javax.sip.header This package contains all the headers interfaces supported by this specification.
javax.sip.message This package contains the interfaces representing SIP messages.


This document specifies the JAINTM SIP API Specification v1.1.


The objective of this specification is to develop a standard interface to the  Session Initiation Protocol (SIP) that can be used independently or by higher level programming entities and environments. This specification was designed to provide a developer with a standardized interface for SIP services which are functionally compatible with the RFC3261 specification. This specification is a general purpose transaction based Java interface to the SIP protocol. It is rich both semantically and in definition to the SIP protocol.

Design approach

JAIN SIP supports RFC 3261 functionality and the following SIP extensions; the INFO method (RFC 2976), Reliability of provisional responses (RFC 3262), Event Notification Framework (RFC 3265), the UPDATE method (RFC 3311), the Reason Header (RFC 3326), the Message method (RFC 3428) defined for instant messaging and the REFER method (RFC 3515).

JAIN SIP standardizes the interface to the generic transactional model defined by the SIP protocol, providing access to dialog functionality from the transaction interface. The architecture is developed for the J2SE environment therefore is event based utilizing the Listener/Provider event model. The specification is asynchronous in nature using transactional identifiers to correlate messages. It defines various factory classes for creating Request and Response messages and SIP headers.  JAIN SIP defines an interface for each Header supported, which can be added to Request or Response messages respectively. These messages are passed to the SipProvider with a transaction to be sent onto the network, while the SipListener listens for incoming Events that encapsulate messages that may be responses to initiated dialogs or new incoming dialogs.

JAIN SIP is extensible by design. It defines a generic extension header interface that can be used by applications that utilize headers that are not supported directly by JAIN SIP. The design also defines a mechanism to support future dialog creation methods in a JAIN SIP environment via the use of Java Properties. JAIN SIP can be managed statically with regards to IP addresses and router function, and dynamically specific to ports and transports. 

The default handling of message retransmissions in JAIN SIP is dependent on the application. Stateful proxy applications need not be concerned with retransmissions as these are handled by JAIN SIP. Typically User Agent applications must handle retransmissions of ACK’s and 2xx Responses, however JAIN SIP provides a convenience function that ensures all retransmissions are handled by the JAIN SIP implementation, reducing the complexity for applications acting as user agents. This function may also be useful if JAIN SIP is used as a base implementation for a SIP Servlet container or an EJB implementation.

The updates incorporated in JAIN SIP v1.1 can be found in the Change-Log.

Specification Leads

Phelim O Doherty, Sun Microsystems Inc.
Ranganathan Mudumbai, National Instituate of Standards and Technology (NIST).

The specification leads would like to acknowledge effort and contributions to the JAIN SIP specification from 8x8, dynamicsoft, Open Cloud, Nortel Networks and Siemens AG. Special thanks is also given to the development team at the NIST this specification owes alot to their commitment in developing the Reference Implementation and Technology Compatibility Kit (TCK) and to Emil Ivov from Louis Pasteur University, France also who helped develop the Technology Compatibility Kit in partnership with NIST.

v1.1 - 23rd June 2003

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Copyright - 2003 Sun Microsystems