SIP Resources

IETF's SIP Charter - http://www.ietf.org/html.charters/sip-charter.html
IETF SIP Working group - http://www.softarmor.com/sipwg/
Columbia's SIP information - http://www.cs.columbia.edu/sip

SIPIT - SIP interoperability test events - http://www.sipit.net

SIP Forum - http://www.sipforum.com
The SIP Center - http://www.sipcenter.com
SIPdev - http://www.sipdev.com
Erik Lagerway's daily comments on VoIP, SIP & IP communications. - http://www.sipthat.com

Free World Dialup - http://www.pulver.com/fwd/
Sipcall - http://www.sipcall.com/
Vonage - http://www.vonage.com/
iconnectHERE - http://www.iconnecthere.com/
SIPphone - http://www.SIPphone.com/