Skype - Dynamic SIP host problem

Hi All,

Our company has skype connect with a online number.
I’ve configured the SIP trunk, firewall and inbound route.

It works most of the time but sometimes inbound does not work.
We get a "The number you dialed is not in service…"
So I assume that my PBX looses it’s registration when this happens.

Skype uses for the sip host and that
can be one of two IP address. and

I found that usually when the IP of changes our
incoming stops working but not always. Sometimes it just stops working for no reason.

What I’ve tried so far:

  • set host to dynamic and ‘allow anonymous’
  • IP Authentication with a SIP trunk for each IP address.
  • changed maxexpiry to 120

It usually shows that it is registered when and I don’t think
that it is my internet connection latency is usually 190-240ms

I did a tcpdump of the ethernet connection and did not see a incoming sip connection from any sip trunk. Just nothing when I call it.

Here is my Trunk settings:


Any help will be appreciated.

Have you figured this out already? I also have the same issue. Hope somebody will post somthing in here :slight_smile:

No. I’ve not been able to figure it out. I’ve contacted Skype
tech support and they believe it is our internet connection.

Because of the amount of traffic we get it kinda makes sense.
Will need to try a dedicated internet connection for this.