No access to VOIP from my network

G

GPSJane

Well-Known Member
Joined
Jun 14, 2009
Messages
482
Reaction score
1
Location
Johannesburg
I have recently started experiencing problems with my ADSL and my modem. The router is the same as before but I have a new modem. The setup is a Buffalo WZR-HP-G300NH and a DLink DSL-2500U.

With my old (Netgear) modem I had full VOIP access but it was also a router so I could plug my phone directly into a LAN port on it. I had never tried it on my router so I don't know if it worked or not.

Now I can't plug the phone into the modem (1 port) so it is on the router. Somewhere along the way it stopped being able to register to the VOIP server. I can't say if it was directly at the same time I got the new modem (I had borrowed one in between and I think it worked for a while).

The router is set up to forward the port 5060 and the modem firewall is disabled. I have also temporarily disabled the router firewall to test it. Still the same problem.

What on earth is wrong?!
 
Last edited:
Ok I was working this out as I wrote this. Thought I had fixed it up. The summary:

VOIP base station - Buffalo Router - DLink Modem - Internet

I get 'registration failed' on the base station. I get that message when internet is down. The base station has an IP and otherwise works. My iPhone has a SIP app and works on another network but not on this one.

All firewalls disabled. Port 5060 forwarded to the correct IP anyway.

I used to have the following and it worked:

Buffalo router - Netgear Modem - Internet
VOIP base station - as above

So basically I don't understand something about VOIP traffic or dd-wrt (on Buffalo router) has some sort of problem.

PS I would know if I was using my landline. I am not an idiot.
 
If I'm understanding you correct you have changed the Netgear Modem to a DLink Modem, otherwise everything else looks the same.

If that is correct, then the problem can only be on the Dlink Modem, as thats the new item in the stack, and the critical one as well, so I'd check there.
 
GPSJane said:
Ok I was working this out as I wrote this. Thought I had fixed it up. The summary:

VOIP base station - Buffalo Router - DLink Modem - Internet

I get 'registration failed' on the base station. I get that message when internet is down. The base station has an IP and otherwise works. My iPhone has a SIP app and works on another network but not on this one.

All firewalls disabled. Port 5060 forwarded to the correct IP anyway.

I used to have the following and it worked:

Buffalo router - Netgear Modem - Internet
VOIP base station - as above

So basically I don't understand something about VOIP traffic or dd-wrt (on Buffalo router) has some sort of problem.

PS I would know if I was using my landline. I am not an idiot.
Click to expand...

Are you using the DLink 2500U in bridging mode? i.e. is the Buffalo doing the PPPoE negotiation with your ISP? (Where is the username and password entered? Buffalo? Or DLink?)

If the DLink is just doing the bridging to ATM/ADSL, and everything regarding the PPPoE connection is being done by the Buffalo, then it sounds like you would need to check the firewall rules that are in place on the Buffalo. What firmware is installed in the Buffalo? DD-WRT? Or the standard Buffalo firmware?

If the DLink is doing the PPPoE connection, AND you have the Buffalo doing NAT as well, then you would need firewall rules on both DLink and Buffalo, and even then you might find it difficult.

From your previous description, it sounds like your VOIP base station was plugged directly into the NetGear, but now that that has been replaced with a 1-port DLink2500U, you have moved it to be behind the Buffalo. In that case, the most likely problem is firewalling rules on the Buffalo.
 
Faulty SIP ALG. Disable the SIP ALG if you can.
Unfortunately not all D-Link models allow you disable their SIP ALG, despite it being thoroughly broken.
D-Link ADSL modems + VoIP = lots of trouble.

If you cannot disable the SIP ALG on the D-Link, remove all intelligence from the D-Link by placing it into bridge mode and then do the PPPoE from a device that doesn't have a faulty SIP ALG. The buffalo may be your solution.
 
@gmza thanks. I found this and you are right. Luckily I was able to disable it because I have not been able to use the Buffalo to manage the PPPoE connection. It may have had something to do with ADSL problems I was experiencing but now that things are working they way they are I will leave it like that!

The problem was not knowing where the issue was - DLink or Buffalo.

The problem now is that since then I have not been able to use the phone to make calls. I get silence on the other end, busy signal when the other line is not busy and general connectivity issues. I seem to have enough bandwidth for this and I have played with the codecs - I have set up the phone to use only the codec Mweb uses and no other. This is a very low-bandwidth codec.
 
Hi all

I still have this issue and have not been able to solve it. I have tried all manner of settings on the DLink. I gather that disabling the SIP ALG might have something to do with this; it needs to be enabled to allow SIP traffic through but it must be disabled to register with the SIP server because it is faulty. Is that correct?

Is there a better modem that I should use? I bought this one because I thought it was one of the best. Now I am just annoyed.
 
Hi GPSJane.

Perhaps we can try to debug why you cannot use the Buffalo to manage the PPPoE connection? The DLink should be connected to the WAN port of the Buffalo, and should be configured in bridge mode. This is what I have in my WAN info page:

Port/VPI/VCI Con. ID Category Service Interface Protocol Igmp QoS State Status IP Address
0/8/35 1 UBR br_0_8_35 nas_0_8_35 Bridge N/A Disabled Enabled Up

Then your ADSL account information should be captured in the Buffalo, using a PPPoE connection (not PPPoA). All your workstations may need to get a new IP address from the Buffalo, if it is not currently acting at the master DHCP server. Either drop the interface temporarily (ifconfig /release && ifconfig /renew), or reboot.

This is the configuration that I think was recommended to you (at least by myself), with which I personally have had very few problems.

Rogan
 
Hi RoganDawes

Yes, I have set it all up correctly and it can't seem to make a connection. I get really tired of troubleshooting stuff that should just work so I don't (I still don't have NAS working on that router either).

I'll try again and let you know.
 
It's like magic; it works :) Thanks. Funny how sometimes it just works after while.

But VOIP still doesn't work. I have tried to forward the relevant ports then I disabled the firewall on the router. I have now placed the VOIP base station in a DMZ.

Frustrating!

PS I am sure this has to do with NAT traversal but I don't know enough to troubleshoot it. I have tried everything that I have found on Google but to no avail. Anyone know enough to help me?
 
Last edited:
Hi There,
I did a bit of digging around for you and came across this rather long blog post which mentions that running VoIP must be done of the modem.
It did have a suggestion of using a WAN bypass which might help and on the same site there is this post which talks about that. It might help you with the NAT.

Have a read and see if it gives more insight into finding the solution.

Regards

Tim
 
Thanks Tim. That is a very good article.

Unfortunately it didn't help as the problem was with the D-Link DSL-2500U. What an absolute piece of junk!

I have replaced it with a TP-Link (similarity in name gave me pause but it is a different make) and everything is much better :)
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X