Does SER support conferencing between user agents that use different codecs (G.729, G.711), or does SIP deal with those kinds of things differently? Also, is there an auto-discovery/zeroconf protocol for SIP user agents to automatically register newly plugged in SIP devices? How does SER compare to sipXproxy? Luis. __________________________________ Do you Yahoo!? New and Improved Yahoo! Mail - 100MB free storage! http://promotions.yahoo.com/new_mail