I already have several SNOM M25 phones and several DECT M700 antennas with OVH SIP lines. They have been working properly for a long time
But since last friday, the outgoing call hangs up after 30 seconds
OVH tells me that there is no problem at home. But there have been changes:
I tried an outgoing call with only one phone turned on and all other phones off, the problem is the same
Here is what I see in your trace:
1. M700 sends INVITE to start the call:
Sent to udp:...159:5060 at 08/04/2019 08:42:08 (996 bytes)
INVITE sip:...@s...user=phone SIP/2.0
2. After some standard message exchange the call is accepted by the remote side with the following 200 OK message:
Received from udp:....159:5060 at 08/04/2019 08:42:15 (841 bytes)
SIP/2.0 200 OK
Look at the Contact header in the 200 OK reply from the remote side: it contains IP address 10.7.1.163. This seems like a private IP from the remote side. Is this IP address reachable to the M700?
From RFC 3261, https://tools.ietf.org/html/rfc3261#section-12:
12.1.1 UAS behavior
The UAS MUST add a Contact header field to
the response. The Contact header field contains an address where the
UAS would like to be contacted for subsequent requests in the dialog
(which includes the ACK for a 2xx response in the case of an INVITE).
Based on the SIP log, the M700 does not send the ACK SIP message which should acknowledge the dialog establishment for this call, probably because it cannot reach IP address 10.7.1.163. Please check on the remote side if this IP is correct.
Note: you have also opened support ticket #19177 for this issue. If you will need to attach further traces, I recommend to use the ticket for privacy reasons. Otherwise you can use either forum or ticket, whichever you prefer.