High concurrent call volume in large call centers can easily exceed the capacity of a single Asterisk server. The upper limit on the call processing capability of Asterisk is influenced by many factors including "codec" conversions and enabling call recording. For very large call volume, the contact center ACD will require multiple Asterisk servers setup in a cluster to handle the maximum concurrent calls. There are a two important considerations for a clustered Asterisk setup.
- Calls can land in any of one the multiple Asterisk servers within the cluster and the call center ACD should be capable of maintaining the call position for proper skills based routing and distribution within the different queues setup for the overall operation.
- The call center software should have a load balancing component that can effectively distribute the incoming calls to the Asterisk servers in the cluster to balance the load.
The ACD will manage call routing and distribution within the contact center software using Asterisk as the media server for voice. Queuing, routing and distribution are the main tasks of any contact center ACD. In a cluster, this ability extends to all the calls in all the queues, irrespective of the Asterisk server these calls land on. The ACD applies skills based routing treating the installation as one entity, irrespective of the number of Asterisk media servers used for land incoming calls.
Load balancing is essential for distributing incoming calls to the servers in an Asterisk cluster. In the case of a single SIP trunk from Telco, the load balancing mechanism has to be in place to distribute the calls among all the servers. The Load balancing SIP proxy has to be set up in a High Availability mode to ensure redundancy.
Q-Suite offers a powerful and feature-rich contact center ACD that can scale to use multiple Asterisk servers as the media server in a cluster. It also has a High Availability Asterisk SIP proxy that performs load balancing, among other functions.