How to load balance two or more Asterisk SIp servers?

I am configuring a Asterisk SIP server. I am able to receive incoming and send outgoing calls. I am worried about more traffic or emergency situations. Please answer the following

  1. How can I configure two or more Asterisk SIP servers to load balance between them?
    1a) Right now I configure all users as . If I am load balancing how should I determine the next available asterisk SIP server ? Is there any existing framework or library or configuration available?

You can use Opensips as a load balancer. It will act as a SIP proxy which sends calls to one of 2 asterisk boxes. If one fails, Opensips sends calls only to one which is alive. It works, but has disadvantages:

  • You have to install Opensips on other server, so You will need 3;
  • For asterisk Opensips is a one peer, so I couldn’t figure out how to make unique settings for every peer that send to Opensips, eg. different codecs order.
  • You have to make some tests;
    and others…but I use this solution and it works well without any issue for about 6 months.
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Thank you very much for answering.

  1. Is there any tutorials on how to set this up?
  2. How many maximum simultaneous calls it could handle?

Yes, load balancing in Opensips is quite well described. I don’t know the number of exact calls, but now it’s about 3000 calls divided into 2 asterisk servers, 1500 per each of them.


Hey, please i have some Questions about Load balancing if you could give me your contact or anything to communicate with you