Asterisk FreePBX server

Hi there,

I’m planning to buy a Dedicated Server for my FreePBX distro with asterisk

and I have 2 simples questions :

What do i need to have a solid server who can handle like 250 simultaneous calls ?

And what happens if i have a server that can handle 10calls max and there is one more trying to call someone. ?

Thank you !

Servers don’t really have call limits. The user/call limits are based on how much the machine can handle without going under heavy load. Those are more guidelines than rules.

1 Like

Any number of things, garbled audio, dropped calls, phones might not register are things that I am aware of.

Bandwidth. Bandwidth in both the computer and in the network. If you look back through the archives, you’ll find lots of posts about how to make a single server do this much work.

PERSONALLY I wouldn’t go for this, but I’m also against virtualization (especially on someone else’s hardware) as a basic tenet of operating a PBX. There will be push-back on that position, but I can only work from experience based on doing this kind of work for the last 45 years.

One of the issues you’ll run into is that each call ends up being it’s own thread, and you want to have enough processor power to make sure that each of the threads can be serviced in a reasonable time. Having said that, though, remember that audio is still a relatively low-impact process, so having a couple dozen threads running on one core is imminently doable.

The things that are going to kill you are the relatively unpredictable things, or the ‘self-harm’ things. you might want to do. For example, dropping a recording of every call onto a hard drive is going to destroy your performance if only because of the non-interruptible IRQs for disk writes. Having a bunch of people suddenly start playing “Doom” over your phone server’s internet connection will as well. Not having a local DNS cache can ruin your day. There are a literal ton of things that can mess up your performance once you start to get out towards the edges of the envelope.

If it was my installation, I’d probably start with a Session Border Controller on the outside of the network with “domain relative” phone servers set up on the inside. I always assume a 10:1 ratio of active calls to telephones (for a normal office environment) and know I can put up to 250 extensions on a single server. This gives you a lot of flexibility, a lot of control over your inbound calling, and a mechanism for balancing your load. It’s a little like partitioning a database - you can split it up horizontally or vertically, based on your particular needs.

Yes, having more than one PBX server can make some processes a little more painful for you (like inter-office extension to extension calling), but these hurdles all have prior art solutions.

People complain about a whole host of random problems. It all depends on what limit you are hitting. If you cheaped out on memory, you could run into problems with packets getting dropped because there’s no RAM available. If your network isn’t sufficient to handle the traffic, you’ll get all sorts of problems like phones dropping off line. If you choose to make dozens of “Busy Indicator” buttons based on Hint processes, you can overload the system. Basically, every problem that you can look through the archives and find can be traced (in one case or another) to improper setup or insufficient resources.

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