Linksys WRT350N w/ DD-WRT & Unknown NAT

[mmcgarri]

I have a HT502 that I am trying to configure with a Linksys WRt350N router running DD-WRT. I call receive and send calls, but when placing calls I do not hear the ringback, nor can I hear the person on the other end - although they can hear me fine.

To troubleshoot this I placed the HT502 in front of the router (connected directly to the cable modem) and it worked perfectly. So I started looking into the router. I disabled SPI firewall, port forwarded all port ranges used by the HT502, but still have the same issues. I saw someone suggest disabling SIP ALG, but I do not have this option.

Not sure if this has anything to do with the issue, but on the status page of the HT502, the NAT is always listed as 'Unknown NAT' or UDP blocked. This is dependent on what is selected for the NAT Traversal (Keep Alive or STUN).

Does anyone have any other suggestions on what to try ?

Thanks.

Mark

[bridonca]

If I were to guess, you have a Rogers Hitron CGN3 modem. It is on the naughty list! Fortunatly Fongo was nice enough to configure a work around.

Rogers Customers with Hitron CGN2/CGN3 Modem, or other users having issues connecting on port 5060:
SIP Server: voip4.freephoneline.ca:6060 Transport UDP

If you are using a Fongo client, you are going to have to get more radical. You would have to upgrade the firmware of the Rogers Hitron CGN3 modem, and then put the CGN3 in bridge mode. That will allow your DD-WRT router to do all the work, and make the Hitron CGN3 a "dumb" modem, as it should be. You should do that anyway, the Rogers Hitron CGN3 modem makes for a putrid router. It is only around because Rogers does not have anything else to run their high speed network.

[mmcgarri]

Hi bridonca.

Thank you for the quick response.

I have a Rogers Motorola Surfboard cable modem (SB5101), however I don't think the issue is with the cable modem, but a setting/configuration of my linksys router (ddwrt). If I have the HT502 between the Cable modem and the linksys router then everything works fine. But if I have it after the linksys router then that is when I run into the issue.

I have also tried it with the SIP server set to voip4.freephoneline.ca:6060, but have the same issue.

I did find out that there is a ddwrt version of the firmware specifically called 'VoIP', do you think that this is required ? Any other suggestions ?

Thank you.

[bridonca]

The VOIP version of DD-WRT is good if you want to set up your own computer as a VOIP provider. It is neat, but since you already have a VOIP provider, (Freephoneline), it is not necessary.

I would be more apt to do a hard reset on the DD-WRT router, and see what happens. If the ATA works great when directly connected to the modem, some setting is mucking up the works on the DD-WRT router, and should work again when you do a hard reset. a 30/30/30 reset would be highly recommended to assure no stray setting is in the memory.

[Mango3]

On the FXS PORT1 page of your ATA, please verify that NAT Traversal is set to Keep-Alive. From your description, I believe it may be configured to use STUN. If it was already set to Keep-Alive, leave it that way, and please try the following, if you have not already done so:

Set up a static IP for your HT502, if it does not already have one.

Set up a port range forward with your DD-WRT router. (Port Forwarding and Port Triggering will not work for this purpose.)

Start: 5004
End: 5029
Protocol: UDP
IP Address: (your HT502's static IP)
Enable: (checked)

Now let us look at your ATA's configuration. Please verify your device is configured as per http://forum.fongo.com/viewtopic.php?f=15&t=16336. I would like to use this configuration, with some modifications:

FXS PORT1:
Local SIP Port: 51482 (this is a random number between 20000 and 65535)
Local RTP Port: 5004 (this is the default)
Use Random Port: No (this is a change from the above link; without this, port range forwarding will not work)

Let us know if this works.

[mmcgarri]

Ok, so I have hard reset the linksys router (30-30-30) and I have applied the settings as Mango3 had suggested - although to FXS Port2. But unfortunately I am having the exact same results

Later today, I will try to reset the HT 502 and reapply all the settings to see if it helps.

[Mango3]

mmcgarri, did you solve your problem yet?

If not, please try to set the following:

ADVANCED SETTINGS
STUN server is: stun.3cx.com

FXS PORT2
NAT Traversal (STUN): Yes

If that solves the problem, remove the port range forwards that I suggested earlier and verify that things are still working.

If that does not solve the problem, remove the STUN server, as it should only be used when things won't work any other way.

[juched]

Same problem here:

Having a problem where I can hear the caller, but they cannot hear me. Also, when calling out I don't hear ringing, but the other side can pickup. Odd. I am running dd-wrt on my router, and I have tried both UPNP and Keep Alive for NAT Traversal.

Ideas? Port forwarding and fixed RTP and SIP ports don't work either.

[Mango]

Please try to set the following:
FXS Port tab -> NAT Traversal: STUN
Advanced Settings tab -> STUN server is: stun.3cx.com

If this does not solve the problem, change these settings back as they were before. A STUN server adds an additional point of failure and should only be used when things won't work any other way.

Let us know if this works, or not.

[juched]

I added the STUN server and rebooted and now it works fine.

Should I leave it?

[Mango]

Leave it for now. You're the second user that has confirmed this workaround. I've PM'd Fongo Support to ask if this will need to be permanent.

[Mango]

Fongo Support suggested you open a ticket to have your account checked. You may wish to mention that you had a one-way audio issue that was resolved by setting up a STUN server.

[juched]

Ok, this is for my Mom which is on FreePhoneLine. I don't see how to open a ticket there yet, but I will keep looking.

Thank you.

[bridonca]

Setting the ATA up to recognize a STUN server is not a bad plan per se, it is just that all that the STUN server configuration does is tell the ATA what type of NAT the VOIP traffic has to go through. Sometimes this is helpful to the ATA, other times it is no help at all. It does not matter what the information is coming out of the external STUN server if the router, and/or modem with a hybrid router attached are not playing nice. That is ultimately where your problem lies. Saying that, if it works, leave it be. Just be happy it works.

[Fongo Support]

Ok, this is for my Mom which is on FreePhoneLine. I don't see how to open a ticket there yet, but I will keep looking.

Thank you.

Hi there,

Please see below:

http://support.fongo.com/anonymous_requests/new

Send me PM with the ticket# once you have opened it.

Regards,

[juched]

Well, the STUN server seemed to work, but then after an hour it would act up and not work properly. It seemed to me if you picked up the phone and called out, then it would work again for a bit.

I opened a ticket, and I got a message back that they forced registration again, and to turn off the ATA for 5 minutes. Before doing this I reset the ATA to use Keep Alive again instead of the STUN server, saved the settings and turned off the ATA for 5 minutes. Now it seems to be stable, audio works in both directions (although my Mom did claim once it didn't work for her correctly, will keep watching).

Not sure what forcing registration can do to help.

[mmcgarri]

Sorry for the delay. Just had a baby boy, so troubleshooting this what down the priority level a bit.

Once I enabled the STUN server everything started working. So following the response that juched received, I switched back to Keep-alive and turned the ata off for 5 minutes. but it stopped working again after that. So I have gone back to the STUN server for NAT Transversal and will keep an eye on it.

[Mango]

Congratulations on the new arrival!

When you get the time, you may want to throw a ticket in. Hopefully Fongo Support can fix your account so that it does not require a STUN server to work.

[juched]

Since support told me they re-registered my account, and switching back to Keep-Alive, it seems to be holding up just fine. Odd. Not sure what re-registering my account really means.