Modern contact center platforms are built on top of powerful technology stack. The underlying stack makes it simpler for the developers of call center software to focus on the building functionality around the two main aspects of voice customer contact, namely the Dialer and the ACD Engine. I am not ignoring the growth in the use of social media and chat within inbound centers for live customer contact. A good ACD should treat be able to all media types and queue them in a similar fashion using skills based routing and queue prioritization.
A look at the modern technology stack available for a contact center platform reveals the extent to which technology stack can impact the architecture of the platform. Operating systems like Linux with its networking tool-sets make it is possible to offer a distributed setup labelled as the Cloud Contact Center. Both the machine and human resources associated with such an operation can be distributed. The growth of VoIP and proliferation of SIP has taken the mystery out of telecom turn-ups and inter-connectivity. The availability of MySQL and Apache has revolutionized database and Web driven interface. Above all, the advent of a powerful hybrid PBX in the form of Asterisk has taken over the complete burden of the underlying telephony platform.
Now, the developers of Call Center Software have only to focus on the functional aspect of Dialer and ACD engine development. It is granted that the expectation from the end-user is a lot higher but this is more due to the maturity of the customer contact center operations as well as the economic pressures of productivity. The availability of feature-rich call center software for Asterisk telephony driven by the technology stack on Linux, MySQL and Apache has contributed greatly to the growth of Cloud and VoIP.