Scalability of Asterisk for larger ACD deployments

Back in late 2002, when we looked at Asterisk as a possible alternative to CTI platforms based on boards from Dialogic and Pika, the very thought of working with open source telephony was exciting.  The possibilities seemed endless and we had limited ability to analyse possible shortcomings moving forward. In mid 1990s the processor speeds in x86 systems made it impossible to conceive voice processing on anything without on-board DSP. The concept of using motherboard CPU for voice processing did cause apprehension but it was counter balanced by the cost savings. With the talk of SIP and IP telephony  as the emerging protocol for voice communication, Asterisk offered a lot of promise. Today we see Asterisk deployments everywhere with limitless applications. With VoIP well entrenched, Asterisk and open source telephony has demonstrated the usefulness and versatility of this hybrid PBX with seamless handling of VoIP and TDM.


Asterisk is extensively used as PBX, gateways, proxys and call center telephony servers. Globalization and online e-commerce has elevated inbound call center services and call handling ACD into an essential aspect of any business. With constant push to lower cost, setting up contact center technology platform based on telephone switches like Avaya, Mitel, Nortel and Alcatel are becoming less attractive options. Asterisk  seem to exceed all available IP telephony options in features and flexibility and is deployable in off the shelf server hardware from vendors like Dell and H.P.  This incredible value proposition is driving growth and expansion of Asterisk in contact centers.


Scaling is an important consideration in the selection of  contact center technology platform to accommodate on going growth in call centers. Asterisk runs on standard x86 hardware and is limited to the processing capability of a single server hardware motherboard and its CPU. This will impose an upper limit on the number concurrent calls that can be processed by the CPU. Requirements like voice recording and transcoding consume CPU power as well. Therefore it is important to select a contact center solution that can scale to multiple Asterisk servers. ACD within the contact center software should be able to handle multiple Asterisk telephony servers to accommodate larger inbound call handling capacity. Indosoft Q-Suite is a contact center software designed to scale to multiple Asterisk servers seamlessly. Q-Suite provides the ability to scale to multiple Asterisk PBX required for large call centers under an unified ACD with all the advanced features like skills based routing, queue prioritization, advanced routing, agent hot desk, overflow and redundancy.