Soft Phone Issue

Joe Della Valle · ‎08-08-2011

We have 2 end user who have Cisco soft-phones they use from laptops. When they are home connected thru a VPN connection, if they call one another they get no sound?

Both have the same model laptop, use a usb headset, and are set up indenticle in CM. If they connect at the office they are fine, they also connect from a remote office thru VPN and the phones work as expected?

So could they have slow internet speed at home causing the issue?

nixon1234 · ‎08-08-2011

What vpn client are they using? We had similar issue with checkpoint and it works fine with juniper.

phamvinhdat · ‎08-08-2011

Check you access list on this.

Dat

mmoulson1 · ‎08-09-2011

Check that there is network connectivity between the VPN users. Remember that the call setup is done via CUCM, so the phones will be able to ring each other as the call going in and out of the server. Once they pick up the call it will try to hand off the RTP stream between the 2 IP soft phones, if there is no network you will just get silence.

Hope that helps!

Matty

Joe Della Valle · ‎08-09-2011

I have compaired 2 different user set ups, and they seem indenticle however one agent can make calls and the other can not when connected theu VPN from home. They both have network connectivity beings they can access all other network apps and functions.

The kicker is that once they are back in the office all functionality is restored?

mmoulson1 · ‎08-09-2011

So the issue is one user cannot make any calls? But the other user can?

The original post said "if they call one another they get no sound"

Does the softphone register with call manager? What does the user get when they try to make a call? Busy tone? Message back from call manager? etc..

Joe Della Valle · ‎08-09-2011

The phone does register with CM. When they make calls from soft phone to soft phone, they see the call pick up but there is no sound, they can't talk to ne another.

It's like a dead mic on the phone.

mmoulson1 · ‎08-09-2011

Can they call other users? Back in the office? Or make external calls to a cell phone for example?

Joe Della Valle · ‎08-09-2011

Yes, it seems only calling between each other do they get dead air?

mmoulson1 · ‎08-09-2011

What VPN platform are you using?

I still standby my original post you probably don’t have network connectivity between the 2 users that are connected via the VPN, they will be able to see the rest of the internal network, servers, CUCM etc. but not connectivity to each other.

If they work in the office the problem must be with the VPN.

Can they ping each other?

Joe Della Valle · ‎08-11-2011

We are using a Cisco VPN client.

Both pc's have to be on the network due to both of the users being able to take and make calls with no interuption. It's just when attempting to connect with each other does the problem arris. I have been able to call them on their soft-phones while they were connected.

I will have them attempt a ping test to each other and see the results on that?

Thanks........

barry · ‎08-11-2011

That's key. In a Cisco telephony world, signalling flows from endpoint (phone) to CUCM. Audio flows directly from endpoint to endpoint. Your VPN users MUST be able to talk to each over the VPN tunnel, and depending on how the VPN is configured this may not be the case.

You need to have spoke to spoke configured on the VPN Head End (prob an ASA). Your VPN access rules need to allow this traffic, and if you're using split tunneling, you need to ensure that the IP Pool for the VPN clients is also passed over the VPN.

Almost definitely a remote access VPN config issue you need to debug.

As an side CUCM Express handles this situation WAY better than CUCM. On CUCME you can configure Media Termination Point (MTP) on a single ephone. This means the audio to / from that specific device is always hair pinned by CUCME. Perfect for remote access VPN users. This function isn't however available in CUCM, or at least wasn't the last time I checked with TAC (which I think was at version 7.1). It would be a real nice to have....

HTH. Barry

Rahul Khude · ‎08-11-2011

Users are able to call each other but gets no sound.

Check out your firewall policies for that vpn. Audio is a real time service, which uses UDP-RTP packets for communication. Make sure you have opened UDP-RTP ports on your firewall.