Session Border Controller Software

[TheMak]

Hi everyone,
we have been using FusionPbx for a while and we are very enthusiasts about it, bytheway there is one sorto of newbie question I'd like to make: is there any possibility or are there any plans to develop some Session Border Controller software to use with FreeSwitch-FusionPbx? I am talking about something like the 3CX SBC which is very usefull to bypass Nat problems. Sorry if this might be a stupid question but I'd like to make an example:

We are an Internet Service Provider, we provide cloud base pbx for our customers and the most common problem when we acquire a new customer wich allready has Voip phones is that 50% of the times they have Cisco Spa phones; those phones are very reliable but it seems that they work in a special way; in most of these installation we have encoutered problems using Cisco Spa (allready tryied everything turing on and of sip alg etc etc) and the solution was giving them a cloud 3cx with a raspberry sbc installed in their network and registering the cisco phones manually on the raspberry (not using the autoprovisioning of 3cx while those phones are not certified). In this way they work like a charm. So this is why I was thinking about having the same thing for Fusionpbx.

Sorry for making it too long
Thanks

 

[Adrian Fretwell]

Ask 10 different people what an SBC is and you will get 10 different answers.

I know you can look up Session Border Controller on Wikipedia:
https://en.wikipedia.org/wiki/Session_border_controller
But in my opinion, an SBC isn't actually a thing, it is a name invented by marketing people to help them sell stuff.

If you specify exactly what you are trying to achieve, I'm sure you will get some guidance.

It sounds like you are looking for more of a SIP proxy / firewall to enhance the capabilities of your PBX, The default install of FusionPBX addresses most of your concerns, provision. NAt etc. and protects itself pretty well. If you are looking for a proxy to front the PBX consider OpenSIPS or Kamailio.

The phone provision facility within FusionPBX is quite comprehensive and will handle Cisco devices

 

[TheMak]

Ask 10 different people what an SBC is and you will get 10 different answers.

I know you can look up Session Border Controller on Wikipedia:
https://en.wikipedia.org/wiki/Session_border_controller
But in my opinion, an SBC isn't actually a thing, it is a name invented by marketing people to help them sell stuff.

If you specify exactly what you are trying to achieve, I'm sure you will get some guidance.

It sounds like you are looking for more of a SIP proxy / firewall to enhance the capabilities of your PBX, The default install of FusionPBX addresses most of your concerns, provision. NAt etc. and protects itself pretty well. If you are looking for a proxy to front the PBX consider OpenSIPS or Kamailio.

The phone provision facility within FusionPBX is quite comprehensive and will handle Cisco devices

Hi Adrian,
Yes I totally agree with You and excuse my ignorance, I even read Your post in some other threads trying to look around for this;

Ok, trying to be as simple as I can: I think 3CX SBC is just a proxy that stables a vpn tunnel with it's relative remote 3CX PBX; the advantage for 3CX is the autoprovision made simple even if the PBX is not in the Local LAN but I am not worried for this, I have used Fusion Autoprovision and it works good; the other advantage of having that "thing" is that I can manually register phones to it's local IP and not directly to the PBX "bypassing" all Nat problems.

Does this makes sense?

Thank You!

 

[Adrian Fretwell]

Hi, yes that does make a lot of sense.

We use mostly UDP, and TCP, where necessary, and generally speaking do not encounter NAT problems. We have had a good few issues where customers routers have had some sort of ALG operating but once switched off FreeSWITCH has handled the NAT perfectly.

We also provide direct SIP trunks, again mostly UDP, and we use fairly aggressive NAT detection rules within our OpenSIPS proxy. We have run the OpenSIPS proxy since early 2016 and thus far have not encountered a NAT issue that we have not been able to deal with.

We have tested various VPN options, but have never put one in to production.

 

[bcmike]

I think the people at 3CX hype up NAT issues a little too much. Everyone that I've encountered from that world is scared to death of NAT.

With todays routers NAT shouldn't be a big deal, sometimes the timers are a little aggressive but it's usually an easy fix. I do however see the the value in an automatically provisioned sip proxy/tunnel client, especially if you're only dealing with one instance which is usually the case with 3CX.

I think in the FusionPBX world encrypting the setup and traffic with TLS and SRTP would be the equivalent to your VPN tunnel and then just having the phones connect through a good NAT router is probably the way to go. If it's a bigger install you might want to install Kamailio as a sip proxy to make things a little more manageable.

Thats my .02 , but as Adrian said everyone has a different way of doing things so your mileage may vary depending on the situation.

 

[DigitalDaz]

I also would like to give a thumbs down to any of this SBC nonsense for NAT traversal. Freeswitch does an amazing job with NAT. Any problems are usually due to misconfiguration, the SBCs/other solutions just help scale.