Hi All, we have a Skype For Business ( Enterprise Voice) with a Direct SIP connections to a PBX (Unify OpenScape Voice).
In some call scenario we found that call transfer from SIP PBX to Skype for Business fails.
Description: Call is offered correctly to the Client Skype but immediately after Client Skype answers the call , the call is realesed from Mediation with a BYE ( I see in sip tracing).
Looking in the Client Logging I see the BYE message with the reason:
ms-diagnostics: 10010;source="VM-LYN-xxxxxxxxxx";reason="Gateway side Media negotiation failed";component="MediationServer";ValidationError="The answer from Gateway has 2 m lines which is different than 1 m lines in our offer.";GatewayFqdn="x.x.x.x;trunk=x.x.x.x"
ms-diagnostics-public: 10010;reason="Gateway side Media negotiation failed";component="MediationServer";ValidationError="The answer from Gateway has 2 m lines which is different than 1 m lines in our offer."
We are trying to mitigate the SDP offer to Skype meanwhile someone knows if the SDP Media parameters in Skype for Business are editable and could be changed?
Thank you in advance
Best Regards
Marco