Kamailio SIP Server Review

​The server itself does load balancing however building a fail-over for it is difficult


What is most valuable?

  • SIP load balancing
  • Authentication

How has it helped my organization?

This product allows you to not worry about problems with growth and scale from the beginning. It has been very reliable as you configure it, then it runs well, and you never really need to touch it once it's setup and working.

What needs improvement?

Would be nice to have more sample config files for different kinds of scenarios rather then just one default config file.

For how long have I used the solution?

Seven years.

What was my experience with deployment of the solution?

The server itself does load balancing however the most difficult thing I found was building a fail-over for it.

However, if you want to build a fail-over for it that's the tricky part since most sip traffic is routed using UDP. There are plenty of amazing TCP load balancers out there such as HAProxy but none for UDP. You need to use something like Keepalive and fail-over IP and restart the server on fail-over

What do I think about the scalability of the solution?

This product can scale insanely.  

The fact that it can handle hundreds of thousands of subscribers is great and means you won't have to worry about scalability for a very long time.

How are customer service and technical support?

They just provide the server open source and I don't use them for support.

Which solution did I use previously and why did I switch?

I previously used Asterisk or Freeswitch to handle registrations and SIP traffic, this is very limited and cannot scale. Kamailio allows you to load balance many Asterisk or Freeswitch servers and move the SIP registration off of the media server allowing for more server resources resulting in more calls per server.

How was the initial setup?

There is a small learning curve, but the hardest part to learn is the configuration syntax which is almost like its own language. Once you get the basics, there are plenty of online tutorials and articles to help you move forward.

What was our ROI?

A better and stable service with load balancing to allow me to guarantee up-time
leads to happier customers.

What's my experience with pricing, setup cost, and licensing?

Set-up cost was my time it took to do the original installation and configuration.
The main cost with this will be your server hosting costs. I personally run this on a virtual machine on a cloud VPS provider.

Which other solutions did I evaluate?

I looked at Opensips which is a similar SIP proxy. I prefer Kamailio and feel the community and the updates, as well as the available modules, are better and easier to work with.

What other advice do I have?

Create a virtual machine and try it out. Try out the different features and different modules available. Check out http://kb.asipto.com/asterisk:realtime:kamailio-4.0.x-asterisk-11.3.0-astdb and see how to use Kamailio with Asterisk.

**Disclosure: I am a real user, and this review is based on my own experience and opinions.
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