Hard Phones vs Softphones

[BrainWreck]

I have a BCM 50 with 8 IP licenses, using 4 Hard Phones and 4 Softphones remotely. My BCM is assigned a static and works fine with teh 4 hard phones. I had one-way audio issues when I added the softphones. I was directed by the reseller to set up VPN using Linksys RV042, which made me assign the BCM a LAN IP, connect it to the router, set up PF on ports 7000, 5989 and assign the router the static IP. All phones connect, the softp[hones work well with VPN, but how do I get the hard phones to work. They connect to the BCM but have no audio.

Does anyone know a config I can use that will make both phone types work remotely or can provide some direction? Any help is appreciated.

 

[SupportDude]

You're missing some ports.
28000 - 28255 UDP.
Those are used for voice path.

-SD-

http://www.mysupportguy.net

 

[BrainWreck]

Definately will try. Appreciate it and will keep you posted. thx.

 

[SupportDude]

Sorry ... just noticed an error.
Should be 28000 to 28511 UDP.
You may also need 51000 to 51063 UDP for RTP/RTPC stream.

-SD-

http://www.mysupportguy.net

 

[BrainWreck]

I tried both. I have no audio. Anything I'm missing?

 

[BrainWreck]

This is on the hard phones as well.

 

[SupportDude]

Checked back through my notes.
My bad again!!!

You already have the signaling port open, or you wouldn't register.
28000 to 28255 UDP
51000 to 51200 UDP
Those should provide your voice paths.

I would have thought the previous should work, since you did open ports in the range.
Maybe it starts at the high port and works in descending order.

Here are a couple of more.

7001 UDP Used to handle the UNIStim exchanges used to
facilitate NAT traversal
7002 UDP Used to handle UNIStim-based IP set firmware
file transfers for the purpose of managing IP set
f/w.

Not sure if one of these is holding you back.
You may need to download WireShark and see you can determine the exact ports being blocked.

-SD-

http://www.mysupportguy.net

 

[BrainWreck]

Thanks again, trying now.

 

[BrainWreck]

Sd- have you seen these major alarms before?
TERM.(0005, :0001): No public media address available for IP set at 10.1.10.187:51010
TERM.(0004, :0001): No public media address available for IP set at 10.1.10.30:51008
TERM.(0008, :0001): No public media address available for IP set at 192.168.200.242:51016

These IP's are not familiar to me. There are not the assigned IP's I use whether behind a router or direct.

 

[telcodog]

I recall having a similar problem a while back and was reminded that the signalling for the ip phones (port 7000) send packets between the ip phone ad the BCM but once the signalling is complete (the far end has answered) then the packets flow from phone to phone directly so you need to make sure there is a route somewhere between your VPN "network" and the network that your phones actually reside on. The fact that you are seeing those errors with ip addresses that you don't recognize would indicate a routing issue, not necessarily a port problem. Those 5xxxx port numbers are the voice packets trying to get to the right destination but don't have a route to get there.

Do you have vpn routers at the remote locations for those hard phones? If not, what is the local network they are connected to? In particular, the default gateways have to be correct too. If not, you will get one-way or no-way voice. Got caught by that one once too.

Can you post some of the ip addresses you're dealing with?

Oh ya. make sure NAT traversal is is active in the router too.

 

[BrainWreck]

No luck yet. Are there any settings in the phone that can help?

Just to back track-the hard phone works fine when I have the BCM connected directly to the Gateway assigned with a static IP. I connect through a VPN Router and Port Forward as directed, UDP, and still no joy. I also connected the BCM as the only device on the gateway so there shouldn't be a bandwidth issue. Nortel recommends the RV042 so that isn't the issue either.

 

[BrainWreck]

Good advice, emillysdad. Checking now.

 

[BrainWreck]

There isn't a VPN on the remote end. How do you suggest I configure with/without a VPN? The Linksys I have does Gateway to Gateway Tunneling but I am not that versed on that set up. What you wrote makes sense. I can connect from one Remote phone to the other but no audio. Thx for your advice.

 

[telcodog]

That's going to be a tough one. Without a VPN that puts all devices on the same network. each router at the remote end needs to know how to get to all the other routers. The only thing I can think of at the moment is to put in static routes and see if that gets you there.

When the ip set tries to make a call, it goes to the S1 server programmed into the phone (which is the BCM itself) so the BCM can ring the set you're trying to call but once that's done, the phone now has to send the voice packets to the ip address of the far end phone but the problem is, without the vpn, it will see the remote phone's ip address that it's local router gave to it, not the wan address of the router. But for the packet to get to the far end set, it needs to send it to the wan address, not the lan address and currently the routers have no idea what that wan address is.

One other question. Can you call any of the remote ip sets and talk from a TDM set on the BCM?

What I would do is start with just 2 of the hard phones and deal with their local routers because once that signalling is done, your Linksys box is pretty much out of the picture in that it is not routing those voice packets. Try putting in a static route to the far end sets router and see if you can talk. Try putting in different default gateways too but be careful if these routers are also used for plain old internet access. You'll need to get the router's wan address but if it's a dhcp setup to the isp keep in mind it can change on you, especially if you reboot it.

I'm pretty sure this is just a routing problem though. We'll get it sorted out!

 

[BrainWreck]

One other question. Can you call any of the remote ip sets and talk from a TDM set on the BCM?"

Same issue. I have 8 analog phones attched to the BCM and no audio when connecting to the remote IP phone DN.

What your are leaning at makes sense. I will think about this a little more.

The actual problem is one of the remote LAN's are using some sort of software based firewall (Linux NetStart or something)They are reluctant to connect the phones outside of the firewall so I am trying to figure this out on my end and not suggest they compromise their network in any way. By setting up teh VPN, the softphones work, but the hard phones do not.

I agree, we will get it figured out. Thanks for your help.

 

[SupportDude]

I have not seen those.
Are these possibly the IP's assigned to the sets during configuration?
This could be giving us a clue to the problem for sure!
I did a quick search of the Nortel Knowledge Base, but only found this.
Are you using NAT?

No speech path on VoIP telephones behind a "port restricting" NAT device.

--------------------------------------------------------------------------------

Problem Description
Deployment of VoIP telephones behind third-party NAT devices, even though not an officially supported configuration, can result in no speech path issues . The unidirectional streams feature breaks compatibility with a specific type of NAT device commonly called "port restricting" NATs. Such devices filter packets flowing from public into private domains and only allow packets from Y:y IP-addressort combinations into the private domain destined to X:x internal addresses if they have seen recently (within 60 sec) at least one packet flowing from X:x to Y:y. Such a packet is said to create a pinhole in the NAT.

With bidirectional streams, when an incoming IP telephone stream is set up by UTPS, the corresponding outgoing RTP stream is always set up by the UTPS on request from MPS. Both streams have matching IP addressing information. The first packet of an outgoing stream generates a pinhole in the NAT. With the introduction of unidirectional streams, this is no longer the case, so when a unidirectional stream is set up, the NAT filters the packets out in multiple scenarios. One such case is a telephone going off hook. A unidirectional stream is open to produce dial tone from the BCM. The NAT does not let the dial tone through. In the case of an outgoing call, the ring back tones are also delivered by means of unidirectional streams. There are perhaps other examples of such issues with background music and music on hold that have not yet been seen in the field, but would most likely exhibit similar behavior.



-SD-

http://www.mysupportguy.net

 

[BrainWreck]

I don't think I am using NAT.

 

[telcodog]

Are the required ports open on the remote routers? Can you ping the wan address of one of the other remote routers?

That firewall is a new twist though. If you don't have access to it, it's going to be difficult to troubleshoot this type of problem.

It's odd that the softphones work ok but the hard ones don't. I will assume that the basic phone ip parameters are set up exactly the same. Do the PCs that the softphones are loaded onto connect to their network via a separate vpn for network access?