Problems with VoIP with Cisco (7940G) & Netgear (RP614v3) using Sipgate! Help Please!

Speed

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Speed

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Hi Guys,

Right I received a new Cisco 7940G a few days ago, as anyone can see from my previous posts the other 7940G one wasn't functioning correctly, down to a faulty SW port. This new one however seems to work pretty well, but I'm still having problems.

My network setup at the moment is very simple, Telewest 10meg Cable Broadband through a standard Surfboard Motorola SB4100 which goes in to my standard wired Netgear RP614v3 4 Port Router. This router shares the internet connection with 4 computers placed around the house.

The Cisco 7940G IP Phone is connected to one of the ports on the router and then the computer which used the port now taken by the Phone is connected to the phone's PC Port. As long as the phone has power, the PC connected to the phone gets internet access fine. Anyways I upgraded the phone to 8.3 firmware and put in all the details, opened the required ports (5060 etc) using port forwarding on my Netgear RP614v3 and the phone didn't work at all.

After some playing around with settings I worked out that disabling the port forwarding using the router to the phones IP gave me some functionality. For example I could dial the 10000 sipgate test number and listen to the recorded message, the phone would also ring when my number was dialled by either mobile or landline phones. Unfortunately when I receive a call there is no audio at all, I expect it is the same with outgoing calls but I have no credit to test it. I am assuming it is down to the required ports being blocked by the router. I tried using port forwarding on just a few ports, same problem, no matter what port I forward the phones IP address it would just stop working, which is very strange.

So I'm at a loss as to what to try next, any suggestions? anyone have similar problems? Would it be anything to do with NAT which I've heard causes problems with VoIP? The phone has a NAT option which is enabled, I’ve tried disabling it but I get the same problem. There is also a NAT Address option on the phone but I’ve no idea what to put there.

Any help or suggestions would be much appreciated!

Thanks,

Mark
(Speed)
 
Anyone? Thinking this is a Router caused problem now. It's the second router I've owned, the first being a D-Link and it's also the second budget type 4 port router I've had problems with. As I've mentioned the phone stops working when I use port forwarding on any of the ports on the phone's IP, it was suggested that I try opening all of the ports on the phones IP address, at first that didn't work as the router doesn't allow you to open the same ports on different IP addresses. Coming up with the error "The Settings were not saved due to an overlap of the Port Ranges", so I deleted all the other entries, opened up all the ports on the phone's IP and the internet access went down on all everything that was connected to the router, PC's and the Phone. Strangely I could ping google.co.uk and all of the other websites I tried with the Command Prompt with each PC, so god knows what's going on.

So could the Router be the problem?

Thinking of investing in something decent like a DrayTek, maybe a 2100 or 2910. Any suggestions? Needs to have 4 ports plus one standard WAN port for the Cable Modem. Obviously has to be reliable, able to cope with high
traffic (bit torrent etc) easy to setup but also configurable with a good
port forwarding setup.
 
So which ports have you forwarded to your handset?
You'll need TCP/UDP 5060 and whatever the media port range is.
Default Start and End Media ports are 16384 and 32766 - the range doesn't need to be as big as this, you'll only use two ports per line. If you have 6 lines, that's 12 ports and if you leave the start at 16384, just change the end to be 16395. In this case you would then forward UDP 16384 - 16395 to your handset.
 
I've tried the standard ports specified by SipGate (5060, 10000 and so on) but as I described in the opening post no matter which ports I forward the phones IP Address, it stops working completely.

Opening all the ports was a suggestion I had from someone, I am aware it isn't necessary.

Something I forgot to mention in my update however was the fact I tried calling an 0800 number and the audio worked fine both ways. So it appears to be limited to incoming calls.

Which is why I'm thinking it could be a problem with the router, if it would allow port forwarding at least I could rule out blocked ports being the cause of the problem.

Any suggestions?
 
this is because IP telephony has trouble working behind a NAT router

you really need to setup STUN so that the IP phone can work out behind NAT, but the sisco phone may not support it.

either that or Set your sisco phone to static IP and forward all necessary incomming and outgoing ports to it.
 
Getting a packet-level trace of the traffic going to and from your phone will probably show you exactly what the problem is, XP with a couple of bridged interfaces or something running Wireshark, but I'd side with MrLOL. Set up STUN if you can ( stun.gmx.de is one I usually use, or SIPGate's), the see how you get on.
 
SIP headers contain the address and ports of the device making or receiving the call - this is why there is problems behind NAT, especially if the device has a private IP address, because the address has to be your WAN IP address.

So, you can use one of:
- STUN which connects to an external server and returns your WAN address - the Cisco phone doesn't support this.
- Manually configure the phone with the WAN IP address - this is the NAT option address you enter and enable, but you'll need to have a fixed WAN address.
- Use an outbound proxy - registration and call setup through this will make the necessary address changes.

So, port forward the required ports, UDP 5060 and the media port range on the router to the phone IP address. Configure the phone with the sipgate SIP proxy and port and also the outbound proxy address and port. User stuff and password as usual.
 
Right, Hi Guys, thanks for the replies.

A few things before I address what people have said. I spent quite a bit of time yesterday trouble shooting and with the help of kind people like Nexy, I made progress. He suggested something that to be honest I had thought of, but didn't know if it would work without a router, this was to connect the phone directly to the modem. This of course completely circumvents the router and to my surprise the phone actually worked completely, even with audio on incoming calls so the router is definitely the problem and like you say this is likely more down to NAT than anything else.

SipGate actually have there own STUN server, unfortunately as Tui points out, it appears Cisco phones don't support STUN.

As for the other two options you've mentioned Tui, I have tried putting the WAN IP in the NAT Address option, but I'm afraid that didn't do anything. I could give it another go however for the sake of making sure.

You also mention using an outbound proxy, what would I actually put in this proxy address field? The default port for the outbound proxy is 5082, I assume that would also have to be forwarded?

My Netgear Router is quite limited with regards to port forwarding and is quite buggy these days, I have numerous problems with it so I am thinking of replacing it regardless of whether I get the phone working through it or not. Likely going with DrayTek, maybe a DrayTek Vigor2100V or even a 2910.

Obviously I don't need VoIP ports, just a solid, reliable 4 port wired router with very a good port forwarding setup, so any suggestions would be great.
 
Did you also enable the NAT option (as well as entering the address)?

For the outbound proxy, remove the NAT option entries and looking at the SIPGATE Help pages has the outbound proxy as sipgate.de:5060, so you would use address 217.10.79.9 and port 5060. Good luck

I would never recommend Netgear routers. Personally, it would have to be Cisco but you are paying for features that most people would not use. Otherwise, I'd go for a Draytek, especially if you need uPnP for MSN multimedia.
 
Tui said:
Did you also enable the NAT option (as well as entering the address)?

For the outbound proxy, remove the NAT option entries and looking at the SIPGATE Help pages has the outbound proxy as sipgate.de:5060, so you would use address 217.10.79.9 and port 5060. Good luck

I would never recommend Netgear routers. Personally, it would have to be Cisco but you are paying for features that most people would not use. Otherwise, I'd go for a Draytek, especially if you need uPnP for MSN multimedia.
Click to expand...

Yes I did enable the NAT Option, just tried it again, along with the uk sipgate outbound proxy and as before forwarding any ports causes the phone to stop working completely.

Indeed Netgear routers don't get a very good write up, I haven't really considered Cisco due to the prices and DrayTek are hardly cheap. Been recently looking at that Linksys WRT54GL as it seems to get a good write up, priced quite cheaply, has the better hardware of the old V4 WRT54G along with Linux firmware, which there are plenty of 3rd party firmware projects for as well.

I’m pretty sure that my current router is at least partly faulty, the fact the phone stops working 90% of the times that port forwarding is used on it’s IP Address.
 
Getting a cisco ip phone to work with NAT is a complete pain, pureply because they were never designed to be used that way. best bet is to get a range of static IPs from your isp and assign it one of those.

or if you're really bored, and have a spare pc kicking around, set up a asterisk box to act as essentially a proxy...(it'll support stun)
 
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