Hello All! I can't register in OpenSER using SIPp. SIPp versions tested 2.0.1 Windows (TLS), Latest from SVN on linux X-Lite registers w/o any problems. In pcap file & messages you can see 2 registration attempts. first form x-lite (successful) and second from SIPp. This looks like OpenSER and SIPp have some differences in MD5 authentication. -- Vladimir Romanov