Apparatus and methods in routing internet protocol network telephony calls in a centrally-managed call center system

A method for routing an Internet Protocol Network Telephony call arriving at a system having a plurality of call centers controlled by a central controller, each of said plurality of call centers periodically sending at least current load status information to said central controller, a specific one of said call centers being temporarily unable to send said current status information to said central controller, said method comprising the steps of:

• retrieving at least load status information of said specific one of said call centers that has been previously sent to said central controller;
• estimating current status of said one call center based on said retrieved status information by determining whether all calls routed to said one call center are likely to be completely processed and further by setting number of calls in a queue and number of busy agents equal to zero if all calls routed to said one call center are likely to be completely processed;
• and
• routing said call by said central controller to one of said plurality of call centers using said estimated status of said one call center and current status information of other call centers.

A method for routing an Internet Protocol Network Telephony call arriving at a system having a plurality of call centers controlled by a central controller, each of said plurality of call centers periodically sending at least current load status information to said central controller, a specific one of said call centers being temporarily unable to send said current status information to said central controller, said method comprising the steps of:

• retrieving at least load status information of said specific one of said call centers that has been previously sent to said central controller;
• estimating current status of said one call center based on said retrieved status information by determining whether an approximate number of unprocessed calls in said one call is less than the number of available agents, and further by setting number of calls in a queue equal to zero if the approximate number of unprocessed calls in said one call is less than the number of available agent;
• and
• routing said call by said central controller to one of said plurality of call centers using said estimated status of said one call center and current status information of other call centers.