Struggling with Grandstream GXW4108

[Ted.D]

I am setting up a 3CX instance for evaluation. The version is: Standard Annual 16.0.8.9. I'm using a Windows 10 Professional VM on Hyper-V as the operating system. I'm using a Sonicwall UTM appliance. It has been configured for the 3CX, and the Firewall Checker passes with no issues.

I have a Grandstream GXW4108 set up as a PSTN gateway. I'm using the support built into 3CX to generate a configuration file for the GXW4108. Loading the configuration appears to work properly (reviewing web setup screens in the GXW4108). The GXW4108 will register after a cold boot (power cycle). It usually takes several soft reboots to get it to register. Once registered, it unregisters fairly quickly, making it difficult to test. I have a ticket open with Grandstream, but they haven't been very helpful.

Just to try something different, I dug out an old Linksys SPA 3000, and set it up as a PSTN gateway. I changed the Outbound rule and tested, and it works exactly as expected. From this, I'm reasonably confident that I have the PBX configured properly for my use case. If I could get the GXW4108 to work, I'd be done with the 3CX evaluation.

Just to cover the easy answers, I have two GXW4108 units, both brand new. Both units behave the same way. I've tried factory defaulting both units and starting over multiple times. I've reviewed all of the relevant articles on the 3CX web site and on the Grandstream web site. I've reviewed all of the relevant articles in these forums.

I may still have missed something in all that material, but it isn't for lack of reading. I'm out of ideas, and a bit frustrated. I'd be grateful for any suggestions. Thanks

 

[leejor]

Other than the unregistration issue, are you able to make or receive any calls, at all? Does the Activity Log provide any clues as to what might be happening?

 

[ChrisC_3CX]

@Ted.D

If you are running the latest version of 3CX (v16.0.8.9), the correct firmware version for the gateway(1.4.1.5 or higher), and have configured it the gateway as per our guide, it should've worked just fine provided of course that everything else is also in order (network configuration, etc).

I think it might be worth running a packet capture on the 3CX PBX and then going through the gateway's provisioning procedure again to check whether you see registration attempts persistently coming in from the gateway as would be expected. If REGISTER messages stop being received, you could then run a packet capture on the gateway side as well (maybe through port mirroring) to determine if the gateway is actually not sending them anymore. In any case, this should at least help you narrow it down quite a bit.

 

[Ted.D]

Thanks for getting back to me. The firmware version is correct. Both units were bought new this year, and the last revision to the GXW410x appears to have been in 2012. I did try a packet capture, but it wasn't helpful. I'll try again next time I'm on site (since a power cycle seems to be the best way to get the GWX4108 to register).

 

[Ted.D]

Other than the unregistration issue, are you able to make or receive any calls, at all? Does the Activity Log provide any clues as to what might be happening?

Thanks for getting back to me. No problems with anything other than the gateway. I am able to make inbound and outbound calls. Changing the GWX4108 gateway to something else (SPA 3000) resolves my gateway problem. The activity log (set to medium) is not helpful (or I'm missing a clue). At any rate, I'm going to do some digging with Wireshark, and maybe try verbose logging, and see if I can get more information.

 

[CentrexJ]

I have sold several of these and the GXW4104. There is an issue with the 3CX template. Generally once the PBX is online and you restart the GXW it should stay stable until the next time the 3CX services restart. At that point you have to restart the GXW and it should run again for a long time until 3CX restarts again.

This fix will help with that. Although from your description its not keeping its connection even with 3CX not restarting. Its worth trying though.

In 3CX go to SIP trunks, Go to your GXW Entry, Scroll to "Authentication" and change it from "Register/Account based" to "Do Not Require - IP Based".

While it will immediately go green on 3CX because that's how 3CX shows IP Based trunks (assumes they are always there and up). Test that you can now make and receive calls.

There may be some additional customization you may have to do to use ports 5-8 as the template is built only for the GXW4014 4 port model but lines 1-4 should work at this point.

.

Good Luck.

 

[ChrisC_3CX]

@CentrexJ

There are no known issues with the specific template though if anything specific has been detected any feedback is welcome.

Regarding changing the Authentication type we would advise against that as the predefined settings are those the specific device has been tested with.

@Ted.D
I'd recommend proceeding with investigating further with wireshark as you have already mentioned and let us know if you find anything noteworthy.

 

[Ted.D]

Grandstream got in touch yesterday, and recommended upgrading the firmware from 1.4.1.5 to 1.4.1.6. Best case, it'll fix the problem; worst case it'll brick the box. I've already got approval to shop for a PSTN gateway brand other than Grandstream, so there's nothing to lose by trying the upgrade. I'll post the outcome here.

Please let me know if you have any thoughts about PSTN gateways (preferably similar to a GXW4108).
Thanks

 

[ChrisC_3CX]

Grandstream got in touch yesterday, and recommended upgrading the firmware from 1.4.1.5 to 1.4.1.6. Best case, it'll fix the problem; worst case it'll brick the box. I've already got approval to shop for a PSTN gateway brand other than Grandstream, so there's nothing to lose by trying the upgrade. I'll post the outcome here.

Yes please do let us know how it goes!

Please let me know if you have any thoughts about PSTN gateways (preferably similar to a GXW4108).

I can't really recommend a specific model but I strongly recommend you pick one from our list of supported devices to maintain 3CX Support and compatibility! Maybe somebody else can chip in here.

 

[Ted.D]

I upgraded the GWX4108 firmware, and the registration issue is mitigated but not entirely resolved. I changed from registration to direct IP (@CentrexJ - thank you for your suggestion). Now I can make a successful call to the SIP trunk DID, answered by the PBX, and forwarded to the PSTN gateway. The audio works both ways, but the quality is horrible.

I have an old Linksys PSTN gateway. It's configured to match the GWX4108 as closely as possible. I changed the gateway in the outbound rule, and repeated the phone call. The audio isn't perfect, but it's entirely adequate. I'll give Grandstream a chance to suggest a fix, but frankly I think it's time to go shopping.

 

[CentrexJ]

What country/region are you in? I use them in Canada/US and quality is fine. its possible it has the wrong tone set for your country.

 

[leejor]

The audio works both ways, but the quality is horrible.

In what way is it "horrible"? Distorted, echo, low volume? First thing is to check, is that the same Codec is being used, from the set to the gateway.

 

[Ted.D]

What country/region are you in? I use them in Canada/US and quality is fine. its possible it has the wrong tone set for your country.

I'm in the US. I checked and the tone set is using the right frequencies and cadences.

 

[Ted.D]

In what way is it "horrible"? Distorted, echo, low volume? First think is to check, is that the same Codec is being used, from the set to the gateway.

Horrible as in it cuts in and out. It's barely good enough to recognize a familiar voice; any sort of conversation is not possible. And yes, the codecs match between the 3CX and the GXW4108. The bandwidth between the two devices is 1 Gb LAN; the bandwidth available to the 3CX through the SonicWall is around 100 Mb.

 

[Ted.D]

I've tried all of your suggestions, and everything I can think of, without success. The Linksys PSTN gateway consistently works - not perfectly (a little static), but well enough. The GXW4108 consistently works poorly. On top of that, the inbuilt web server is so slow that about 20% of screen re-paints time out. I've ordered a different PSTN gateway; I'll see what joy that may bring. Thank you all for your help.

 

[leejor]

On top of that, the inbuilt web server is so slow that about 20% of screen re-paints time out.

This information, on top of the poor quality may indicate an issue with the unit itself, or a network problem. Have you tried moving the gateway to another router/switch port, used a different cable/Ethernet socket, etc.?

 

[ChrisC_3CX]

And yes, the codecs match between the 3CX and the GXW4108

Just to clarify here in case it was misunderstood. The codecs between the 3CX PBX and the Gateway should indeed match, however, the codecs between the 3CX endpoints (3CX Clients, IP Phones, etc) and the 3CX PBX should match those between the 3CX PBX and the Gateway too in order to reduce transcoding to a minimum. That said, ideally you would want the same codec to be the priority for every call leg across the 3CX PBX regardless of whether it's an external, internal call and who initiated the call.

Do bear in mind that in V18 major changes have been made to mitigate audio issues related to codec configuration so you could just wait for it's official release to see if the situation improves just by upgrading.

 

[SweetAction]

Sounds like a networking issue to be honest. Lost packets between 3CX and the GW.

Any duplicate IP conflicts? Check if the arp entry for that IP keeps changing? Bad cable or switchport?

We use/love Patton for PTSN gateways but it's directly proportional - more money, less problems.