Phone: Innovaphone IP112A DTLS-SRTP cooperation
Hello guys,
I'm trying to get SIP over TLS and RTP over DTLS-SRTP secure calls working between a Linphone (Android 5.2.0-alpha) SW SIP client and an Innovaphone IP112A (firmware 13r3 137919 sr11).
I have already addressed the problem with SDP Media description profile that Innovaphone was sending in the wrong format (RTP/SAVP vs. UDP/TLS/RTP/SAVP) here on the forum. This error was already fixed by the developers in 13r2 (thank you very much), but now I am facing similar problem.
The problem is as follows:
- If I call from Innovaphone IP112 to Linphone using DTLS-SRTP encryption and SIP over TLS, the signaling and the subsequent call are connected and everything goes well.
- If I make a call from the Linphone SW client to the Innovaphone, the signaling goes through without any problems, but when the call is picked up on the Innovaphone side, the call ends immediately and a message pops up on the Linphone - Null/0 error.
- I switched the signaling back to SIP over UDP to see the content of the SIP messages and found out, that on an INVITE request from Linphone that contains an SDP Media description (audio port_number UDP/TLS/RTP/SAVP) the Innovaphone returns a 200 OK response with SDP media description (audio 0 RTP/SAVP) where a 0 in the port position says that the connection cannot be established. But why does Innovaphone respond to the UDP/TLS/RTP/SAVP profile with the RTP/SAVP profile?
respectively where could be the problem please??
- I attach the intercepted communication in .pcap, when filtering the SIP protocol, the communication can be seen.
- the testbed is as follows: Linphone is registered with SIP account 15 and has IP address 10.10.0.142, Kamailio SIP proxy is running on IP 10.10.0.190, which routes SIP messages between clients, and Innovaphone is registered with SIP account 12 with IP 10.10.0.150. I turned different audio codecs off and on, tried different combinations and unfortunately it didn't help.
I will be very grateful for any advice and help, best regards and Have a nice day,
Filip
(Edited by Christoph Künkel (innovaphone)) -- moved it to the English forum
Linphone_15_142_to_Innovaphone_12_150_broken.pcapng