Those familiar with Asterisk will know about IAX - the Inter Asterisk eXchange protocol, which makes it very easy to connect multiple asterisk servers together and traverse firewalls etc.

However, IAX was never designed with volume in mind, and in particular, if the IAX server at your telco had a problem or changed IP address, the customer needed to restart asterisk to re-establish the connection. It also meant we were constrained by the number of concurrent calls we could fit on a single CPU, as asterisk locks itself to only talking to a single IP address.

We have therefore implemented the world’s first (and, we think, only) IAX load balancer (source available) - under test we put 400 concurrent calls through it.

We can now offer inbound and outbound IAX trunking, through our load balancers, which should improve quality and reliability. At present, we have two asterisk servers behind the load balancer - but many more are easily added.

To send calls to us use your normal gradwell IAX details, but use iax-lb.gradwell.net as the hostname, instead of iax.gradwell.net or iax-out.gradwell.net.

If you would like your inbound calls load balanced, please drop us an email to support telling us the number and we will enable it for you.