This seems to me to be getting down to some sort of problem with configuring the Snom-870. when I register the device 41712 (set up for transport=tls only) then I see this in the SIP trace: Sent to udp:192.168.6.9:5060 at 4/3/2015 09:07:36:813 (836 bytes): REGISTER sip:voinet09.internal.hamilton.harte-lyne.ca:5061 SIP/2.0 Via: SIP/2.0/UDP 192.168.6.112:5060;branch=z9hG4bK-udx92poqese6;rport From: "James B Byrne" <sip:41712 at voinet09.internal.hamilton.harte-lyne.ca:5061>;tag=frgaimnglp To: "James B Byrne" <sip:41712 at voinet09.internal.hamilton.harte-lyne.ca:5061> Call-ID: 710000004941-gk6y4evf6dci CSeq: 482 REGISTER Max-Forwards: 70 Contact: <sip:41712 at 192.168.6.112:5060;line=0p8zx4sh>;reg-id=1;q=1.0;+sip.instance="<urn:uuid:ad1349a7-e08d-411b-83b0-000413281B56>";audio;mobility="fixed";duplex="full";description="snom870";actor="principal";events="dialog";methods="INVITE,ACK,CANCEL,BYE,REFER,OPTIONS,NOTIFY,SUBSCRIBE,PRACK,MESSAGE,INFO" User-Agent: snom870/8.7.3.25.5 Allow-Events: dialog X-Real-IP: 192.168.6.112 Supported: path, gruu Expires: 3600 Content-Length: 0 The SNOM-870 is sending registration via UDP and not by TLS. Is that how things are supposed to work? If only TLS is enabled in Asterisk for that peer then evidently the peer cannot register. But is registration supposed to be done via TLS? If so then how does one configure the Snom to do so? -- *** E-Mail is NOT a SECURE channel *** James B. Byrne mailto:ByrneJB at Harte-Lyne.ca Harte & Lyne Limited http://www.harte-lyne.ca 9 Brockley Drive vox: +1 905 561 1241 Hamilton, Ontario fax: +1 905 561 0757 Canada L8E 3C3