SIP

RFC

SIP: Session Initiation Protocol

http://www.ietf.org/rfc/rfc3261.txt

 

Stack

MjSip

http://mjsip.org/

 

JAIN-SIP

http://snad.ncsl.nist.gov/proj/iptel/

 

oSIP

http://www.gnu.org/software/osip/

 

eXosip

http://savannah.nongnu.org/projects/exosip/

 

 

 

Application

sipdroid

http://code.google.com/p/sipdroid/

 

SIP Communicator

http://www.sip-communicator.org/