I agree about the reason. So far, we had mix results as one model of our laptops fleet doesn't work with Checkpoint Capsule VPN, R77.30, Jabber 11.9 and 12.1. So far, it appears that the sound card doesn't switch to the right output. The wireshark pcap has shown that the SIP conversion is completing with no known errors. Also I can't seem blocks or dropped packets on the VPN session. So in our case, I think it more to do with the audio drivers over a network issue.
