Skype dropping call

Skype dropping call after 12 seconds with no audio

Problem

I was at a client today and they had an issue with Skype dropping a call after 12 seconds and there was no audio from both sides.

The client has a VMware Horizon vdi solution and the problem initially was calling from within the vdi environment.

I did some trouble shooting, internally, externally and from my laptop on the wifi. I experienced the same problem. So the problem was not the vdi side.

I concluded that there must be an issue on the firewall.

Solution

I called up the guys that manage the firewall and asked them to check that TCP ports 80 and 443 are open on the network they said that is was open as that is what it says on Skype's website:

But what they don't tell you is that you also need UDP port 3480 opened. Once you open those three ports...

Problem solved...

Keep on keeping on...