Hi i have a UC520 whit mostly SCCP phones and 1 phone 8961 (SIP) and 1 Jabber on Iphone, the issue is when this devices call to any extension after 15-18 seconds the call drops, but when i call from a diffrent phone to any of this 2 devices the call works whit no problem, the UC520 is loaded whit the 8.6.2 software pack and the 8961 have the latest fimware.
