Jabber To Jabber Over VPN

[Fergie M]

Hello

I have only discovered this issue after having Cisco Jabber (nee Communicator!) over the last 6 years.

We are running Jabber 11.8 on Windows, and all the softphone elements work within our corporate lan.

When users connect into our office over VPN, the user can also make/receive calls/im/presence as normal. Perfect so far.

But, I have discovered if 2 users on VPN , try to dial each other, the phone call will come through and once the call is connected no audio, or video will happen on either side. The call will stay happily connected. I know the call manager steps up the call and then drops off once the end points are connect.

I checked my firewall logs but I can't see any dropped traffic coming or going from either client. Routing is fine , no IPS.

Has any one got anything I could check or had this issue before?

[Dennis Mink]

yeah, so if your two VPN end points call each other, all cucm does is signal both Jabber clients with eachothers IP address (Which can be found in the SDP once you capture the SIP traces for that particular call).

I am guessing that RTP cant be established between the two client, as RTP would be point to point.

Can you ping between the two clients?  can you packet capture on your FW to see if RTP is being sent by cleint A (or B for that matter). what firewall is it BTW?

Please rate if helpful

[Fergie M]

It's a checkpoint firewall. No I can't ping between the 2 devices on VPN.

Actually , something to check.... the ip address the laptop gets from VPN , is not the same as the Jabber Client. Right? Never thought of that , which means I wasn't even looking at the correct logs to start with.

[matthew dearden]

Evening,

My team and I just fixed this issue. We are using Cisco AnyConnect VPN client and Cico ASA5545X firewall and Cisco Call Manager 12.x

There are two issues, firstly the VPN ACL you use needs to have all the required ports open. This is a challenge because there are more ports needed than listed in the Cisco docs. We enabled ANY IP as a test and this allowed jabber clients to hear ringing when the call was being setup between the jabber clients.

The next issue is on the Cisco ASA you need to tick "Allow communication between hosts on the same interface" within the ASDM on the interface configuration page. After you do this you can ping between two clients on the VPN.

We now have two way voice working between two jabber clients on VPN.

I know this post is from 2017 but hopefully this helps somebody.

Matt