Many sip phones behind NAT


Has anyone launched over 100 phones from behind NAT?
Are there any problems?
Any other solutions?
(I’m thinking to use IPv6, but the FreePBX server doesn’t have an IPv6 address yet)
I will be using Ubiquiti ER-4


For me, no.

Any other solutions for what? I’m not even sure what the first solution is.

1 Like

You pretty much need a static IP for this so you can whitelist it or you need to disable fail2ban. If you don’t I can pretty much guarantee you will end up banning the entire office repeatedly.

Or the first problem…

Have we talked about VPN solutions yet, or is this idea space limited to NAT?


Let me take the idea a step further. If you are going to VPN a fleet of phones to a cloud PBX, at what point does it make more sense to bring the PBX to the same network as the phones? 100 endpoints? 1000?

I say 112 - 111 is probably OK, but 112 is right out.

My natural inclination is to bring this phone system in-house for way fewer than that anyway, but I’m old and weak of mind… You kids and your “cloudy computer” thingees - whatever happened to being able to turn the crank and ask Gladys to connect you to Mabel’s house?



I am not even sure what the problem is here. I have deployed 110+ devices behind NAT with no issues. I have seen 10 devices behind NAT cause things to go crazy while 110 behind NAT is purring along fine. It comes down to the network. A crappy network is just a crappy network.

On top of that, the OP mentioned using IPv6 which makes all the NAT talk moot. Until the OP clarifies this is all peeing into the wind.

1 Like

I have experience with the EdgeRouter series and can say that an ER-4 will readily handle 100+ phones behind the NAT. (if configured correctly of course)

There is a SIP ALG enabled by default on the ER and that should be turned off when using Asterisk’s NAT handling functionality (preferred).

1 Like

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.