Listing of Public SIP Servers

For testing and debugging purposes, the following SIP servers are available. Note that the SIP URL does not work with regular browsers such as Netscape (any version) or IE. It requires a modified browser that understands the SIP URL scheme. No such browsers exist at this time, as far as I know, although it should be possible to modify Mozilla accordingly.
Organization SIP URL (note: clicking on it will not work with regular browsers!) SRV record? transport mode accept registrations from other domains? remarks
hotfoon no UDP redirect New users have to create their own userids on the server by sending a REGISTER message that has the same password specified on both Contact and To fields. If you attempt to recreate an existing userid, a 409 (Conflict) error is returned. For example, shoot test.txt 5060.
Via: SIP/2.0/UDP
Expires: 7200
Contact: Alice 
Registrations expire in 5 minutes (we are at the moment ignoring the Expiry header). Users are adivsed to keep refreshing their registration every 2-3 minutes. UDP redirect and proxy no Users can create accounts and use the as their address-of-record
Lucent Technologies, Inc. No UDP, TCP redirect, proxy yes (no password or registration required) Contact Vijay Gurbani with questions or comments.
Centre of Network Research, Computer Engineering Department, Prince of Songkhla University, Thailand No UDP, TCP redirect, proxy; default is redirect yes (no password or registration required) The server sets Expire depending on user Expire, with default expiration of one hour. The server can fork when a user register in our sip server more than one address and user set action to proxy, if action is redirect then our sip server will return back all addresses. Any Callers those not registered with our sip server can invite any Callee. (Note that now every callee must be registered with the server.) Contact Jessada Tepsoontorn for further details.
Pingtel interoperability test server -- TCP and UDP proxy yes See for a series of tests to exercise SIP user agents.
Vienna University of Technology, Institute of Communication Networks No UDP, TCP proxy yes The server implements the SIP Servlet API. More information is available at Contact Johannes Stadler or Igor Miladinovic with questions or comments.
zdots (Microappliances) no UDP, TCP proxy no
Nortel sipfx UDP, TCP redirect and proxy yes
sipcenter (Ubiquity) no UDP, TCP redirect and proxy yes
3Com siphappens UDP only redirect and proxy yes
MCI SIP interoperability test web no UDP, TCP redirect and proxy yes

Last updated by Henning Schulzrinne