sundance-communications.com/forum Forums TDM Business Telephone Systems Toshiba Telephones & Systems home IP phone - no audio with DiffServ

Hello all!

I've posted previouslyabout this, but I wanted to start a new, specific topic.
(https://www.sundance-communications.com/forum/ultimatebb.php?/ubb/get_topic/f/11/t/001836.html)

My LIPUs are currently all addressed privately. I MUST do this as I am on an MPLS network and I only have 1 internet connection which is at the data center of my ISP.

So, to have home users with IP phones I MUST do hardware VPNs. I hate this, but so it is with Toshiba.

My ISP and I have worked together to implement QoS with DiffServ. So, my site-site IP-Qsigg traffic gets prioritized.

I have 3 home users with phones. 2 of them have Linksys WRV54g vpn routers and are working ok. The 3rd has a Linksys WRV200, and she gets no audio (though she can send audio). When I turn DiffServ off, audio works.

Toshiba doesn't do NAT. I'm using DiffServ for QoS between offices.

Anyone have any ideas or suggestions? I'm getting another router to test with...

Make sure the proper ports are open on the router at the location that is having the problem.

Here's a list of ports I got from someone on this board (newtechy maybe...).

What ports do I need to make sure are open?

Again, I have 3 people using the phones - for 2 it works, and for the 3rd it's failing.

I just now (today) experienced a 4th that was having the problem when using the softipt over a cisco (software) vpn. Again, turning diffserv off solved the issue. But, since I'm using DiffServ for QoS this isn't a good solution for me....

Connection Request
StrataNet (QSIG)
4029
TCP

Call Control Channel
StrataNet (QSIG)
6400-8191
TCP

Registering IPT
RAS (H.225)
1718, 1719
UDP

IPT
RTP/RTCP
1500-1503
UDP

IPT
RAS/MEGACO
45152 and 45153 (default)
UDP

Call Control Channel
MEGACO+
2944
TCP

Media Channel for TDM
RTP/RTCP
16384-16511
UDP

Medial Channel for NAT
RTP
20480-20991
UDP

Medial Channel for IP QSIG
RTP/RTCP
20992-24575
UDP

<sigh> I put my PC in the "DMZ" for my router, and I turned off my windows firewall, but no use.

I don't know why DiffServ would make a difference if it's going over a VPN. I mean, the concept is that some internet router would have an issue with it, but if it's on a VPN the internet routers shouldn't even see the encapsulated traffic.

And, why would it work for a couple phones, but not a 3rd?

Perhaps I can strip the diffserv info out of the packets on my switch when the destination isn't one of the ipt phones - so that diffserf info only goes to other switches.

<Sigh> Toshiba. They tell me I must use VPNs to make it work through NAT, and that DiffServ is their wqay of supporting QoS - but, if you use QoS you get one way audio. <sigh>.

Anyone have an idea on how this can work? I need QoS (site-site). I need IPTs at people's houses.

Do you have stateful packet inspection disabled on your home router?

The newer Linksys routers have port-based or MAC-based QoS built-in. Set the QoS to high for the MAC address of the phone or the physical port the phone is plugged into, leave everything else set to low.

Ok, I did quite qa bit of more testing, all turned out bad.

I got the phone and router back from the user that was having problems, and connected it to a hub on the outside of my firewall. I resetup the VPN with the new IP address. It worked fine.

Also, I tested a softIPT from MY house, and had the same problem - one way audio with DiffServ on. I plugged into a different linksys router (a normal linksys router, not a VPN router) - this router is also on the hub on the outside of my firewall, and did the Cisco VPN I use at my house - and it works fine.

So it definately looks like it's a problem with DiffServ. It doesn't make sense to me since I assume all traffic get's encrypted and sent over the VPN.

I also setup a traffic analyzer on my laptop and check what traffic was working and what wasn't, and I discovered the softIPT uses 2 sets of ports. It uses 1718 and 1719 for setup, then 164xx and 164xx (xx=dynamic) for the actuall dialog traffic. On one of the dynamic ports, it was sending but not receiving. The difference was DiffServ.

<sigh>. Since I'm using diffserve for QoS between offices, I don't know what I'm supposed to do to get QoS to work. It will have to be setup in the infrastructure I suppose, and not the phone system.

I can't help but blame Toshiba for this.....it may not be their fault, but....<sigh>. It works on 2 phones, but not on 2 others.

If anyone has any ideas, I'm open.

junkman and phonemeister, thanks for your suggestions.

Ok, for those that are interested in this thread...

I checked with my vendor and they said they've done 2 things when they've had this issue: 1) turn QoS off on the phone system, and have the ISP do QoS based on IP address, 2) use ToS not DiffServe.

My ISP said they don't think they can do QoS based on IP, they're setup for DiffServ. They said if the ToS bits are the same as the DiffServ bits (mess with the ToS fields so they = what the DiffServ DSCP value would be) it SHOULD work. Testing required.

My final solution will be to turn the QoS off on the phone system and instead have my intelligent switches monitor the traffic passing through them. Whenever any traffic goes to the IP of the phone system the switch will insert a DiffServ value into it.

Please keep us updated.

I had this problem with a remote user one time on a BIPU. after some checking we turned DIFFSERV off in the phone system and all was working fine. If your remote user is using many hops to get back to your site, one or more of those hops may not be able to pass Diffserv. This was the case in problem.