Remote extensions does not register via 4G internet

[Guy Perera]

Hi Guys,

I have a FusionsPBX on AWS. Few Polycom handsets on multi tenant setup are connected to it. Works really well.

Due to some Internet Outage on a site using ADSL, I'm trying to connect 2 Polycom phones via a LTE Router.

I live in Australia and I'm using a Telstra as the Mobile data service. I have already tried it with a mobile data service called VIVID Mobile Broadband, that works fine few months back. But I'm trying to find a solution while using Telstra Mobile Internet. On top of that, any ZOIPER soft extension works fine on LTE (registration, stability and voice), the issue is only for SIP Phones (Polycom).

I understand there soo many things to check in this type of a troubleshoot.

I was wondering if anyone here had a similar experience connecting extensions via mobile internet to a cloud hosted FusionPBX.

I suspect, it's due to Public IPs are NAT, although I see Dynamic Public IPs on Telstra Mobile Internet.

Any help is much appreciated.

Thank you.

 

[DigitalDaz]

I think the Polycoms though great phones are not the best for NAT, they do not, as far as I know, have the ability to set rport and this is probably the setting you want. The softphones will be able to handle the NAT better. Maybe someone with more Polycom experience will chip in.

 

[EasyBB]

There are a few points to consider.

• Don't use Optus or its MVNOs as their network blocks port 5060. Ofcourse you can use a non-standard port and get around it. I am guessing by saying "VIVID Mobile" you actually mean Vivid Wireless?
• Telstra 4G is CGNATed but VoIP phones generally work over it. Just be careful using Polycoms on Telstra network as Telstra uses Polycom for its own hosted pbx product, so its network/routers are set up to redirect Polycoms to Telstra's own provisioning server which will reset your phone. You can set a static provisioning server address to get around this.
• You need to make sure SIP INVITE/REGISTER packet size from Polycom to not exceed the 4G network's MTU. If Zoiper works, use its packet size as a reference.

 

[Guy Perera]

Thank you both for replies.

Hi @DigitalDaz, I'm using a polycom 550 for testing. Not sure how to change the rport on it. Not a setting available in both Phone or LTE Router.

Hi @EasyBB,
1. Yes, it's Vivid Wireless Boardband. This is the connection I was able to work with. I will be testing it next week when I get my hand on to a connection from them.
2. Yes, Polycom handsets provisions to Telstra overnight, no questions, learned it the hard way, few times.
3. Is MTU Size a setting on the Modem or on the Phone? I can't see that anywhere.

My current Test Bench:
FusionPBX running on AWS
2 SIMS, obtained a Optus Postpaid Internet connections
and a Boost Prepaid Data SIM runs on Telstra network.
LTE Router is a TP-link TL-MR6400
Polycom IP550 extension.

With Optus Mobile Internet, I was able to get the extension registered and audio to work one way. The extension can not hear a call from a mobile. But the mobile can hear the extension.

Attached image - The second registration shows is the registration via Optus Mobile connection. LAN IP displays the public IP of the data connection, which is abnormal. Audio works one way. But the registration is stable.

When I remove the Optus and Insert Telstra (while the router is powered), the first registration picks up just for once. This registration shows the LAN and Public IPs Correctly. But it's just timeout after once instance of a registration attempt.

Then both the registration records time out.

What could be the possibility reason behind one way audio with Optus or Registration does not continue with Telstra?

Thank you for your time.

 

[EasyBB]

Not a great idea to try multiple registrations for the same extension while you are still having issues.

I've already explained the situation with Optus network. I can register and make calls fine on Telstra network using IP 550 phone. I don't have a FusionPBX on the internet so I am using a VSP account to test.

Happy to run a test for you against your Fusion box if you like.

Is MTU Size a setting on the Modem or on the Phone? I can't see that anywhere.

On the router.

 

[tdcockers]

Sorry for late reply... what router are you using? I found that with pfSense, if you leave the block private addresses ticked under the interface configuration, it blocked all traffic from CGNAT devices. The option for me was to create an alias for the RFC1918 items other than the 10.x.x.x range, block them with a rule and allow the 10.x.x.x through