I would suggest reading some whitepapers on SIP. It is a good starting point and depending on your specific situation will help.
If we make SIP as contact center server, we can gain below functionalities:
- Unified communication is possible (each customer having multiple contacts – Mobile/PSTN/Email/etc…) means, if the administrator wants to send a message to customer or a subscriber, he/she can send it based on the availability of the contact. i.e If he is now available in Mobile/E-mail based on the status (presence feature of the SIP) the contact center server can send a message to the contact.
- In case of call center – SIP can provide forking mechanism or Call distribution/Call hunting/call forwarding functionality.
- SIP is through IP. so, business wise lot of benefit.