Monday, October 26, 2009

Mobicents SIP Load Balancing

Check out our SIP Load Balancing (SIP LB) designs and deployment scenarios.

Our goal is to support as many scenarios as possible in a simple way and maintain flexibility for future enhancements and custom load balancing. We look at the load-balancer as a platform where you can implement your own routing decision logic - distributed or standalone, stateful or stateless, layer 3/4 or layer 7, it is all up to you.

The new load balancer provides quite a few improvements on top of the old one:
  • Performance (>1000 cps, but depending on the algorithm)
  • Flexibility - pluggable algorithms and customizable algorithms
  • Fault Tolerance - multiple smart SIP LBs can work together and nterchangeably in case of failure when sprayed by "dumb" IP load balancers
  • Cooperative Load Balancing - very often, mutliple protocols and sessions are involved in a telco service. Then you need to group calls, HTTP or other protocol sessions to stick together and be failed-over together. Only your application knows the right way to group these sessions, thus sometimes it is crucial to delegate load-balancing decisions to your application. Now, you could implement your own algorithms that take hints or instructions from the applications.
For more details you can look at these slides:

Feedback is welcome!

UPDATE: Revised November 1st, 2009