Throttling behavior is specified by the following three parameters.
1. MaxConcurrentCalls - Total no of concurrent calls service will accept
2. MaxConcurrentSessions - Total no of sessionful channels service will accept
3. MaxConcurrentInstances - Total no of service instances will be created for servicing requests.
It can be specifed either through code or configuration file. It requires the "System.SystemModel.Behavior" namespace to be included.