I am trying to configure [Linphone][1] to wrap all media communications in an encryption layer (on Xubuntu). According to [their website][2], Linphone supports: > Secure communications (TLS, SRTP, zRTP) However, when I try to configure Linphone in `Options > Prefs > Network Settings > Network protocol` and select `SIP (TLS)` then Linphone immediately complains with the following error message: Could not start tls transport on port 5060, maybe this port is already used. Linphone works just fine when I switch back to `SIP (UDP)`. What is wrong and how can I fix it? [1]: http://www.linphone.org/ [2]: http://www.linphone.org/technical-corner/linphone.html

I am trying to configure [Linphone][1] to wrap all media communications in an encryption layer (on Xubuntu). According to [their website][2], Linphone supports: > Secure communications (TLS, SRTP, zRTP) However, when I try to configure Linphone in `Options > Prefs > Network Settings > Network protocol` and select `SIP (TLS)` then Linphone immediately complains with the following error message: Could not start tls transport on port 5060, maybe this port is already used. Linphone works just fine when I switch back to `SIP (UDP)`. What is wrong and how can I fix it? [1]: http://www.linphone.org/ [2]: http://www.linphone.org/technical-corner/linphone.html

I am trying to configure [Linphone][1] to wrap all media communications in an encryption layer (on Xubuntu). According to [their website][2], Linphone supports: > Secure communications (TLS, SRTP, zRTP) However, when I try to configure Linphone in `Options > Prefs > Network Settings > Network protocol` and select `SIP (TLS)` then Linphone immediately complains with the following error message: Could not start tls transport on port 5060, maybe this port is already used. Linphone works just fine when I switch back to `SIP (UDP)`. What is wrong and how can I fix it? [1]: http://www.linphone.org/ [2]: http://www.linphone.org/technical-corner/linphone.html

I am trying to configure [Linphone][1] to wrap all media communications in an encryption layer (on Xubuntu). According to [their website][2], Linphone supports: > Secure communications (TLS, SRTP, zRTP) However, when I try to configure Linphone in `Options > Prefs > Network Settings > Network protocol` and select `SIP (TLS)` then Linphone immediately complains with the following error message: Could not start tls transport on port 5060, maybe this port is already used. Linphone works just fine when I switch back to `SIP (UDP)`. What is wrong and how can I fix it? [1]: http://www.linphone.org/ [2]: http://www.linphone.org/technical-corner/linphone.html