A Switching system that provides traffic concentration and distributes calls between end offices or to an inter-exchange carrier.

A Switching system that provides traffic concentration and distributes calls between end offices or to an inter-exchange carrier.

• A. End Office
• B. Exchange Area
• C. Selective Router
• D. TSP

Answer: (C)

This question tests how 9-1-1 network switches manage call flow. A selective router is the node that gathers many 9-1-1 trunks from multiple local end offices and concentrates that traffic, then distributes each call to the appropriate destination—either the correct PSAP via an end office or to an inter-exchange carrier for routing to another area. In other words, it centralizes incoming 9-1-1 traffic and directs it to the right place based on the caller’s location information. The other options don’t perform this cross-office concentration and routing role: an End Office is the local switch that terminates subscriber lines and handles basic call processing but doesn’t aggregate traffic from multiple offices or route to IECs; an Exchange Area is a geographic grouping rather than a switching node; and a TSP (Toll Service Provider) is a service provider, not the routing switch in a 9-1-1 network.

This question tests how 9-1-1 network switches manage call flow. A selective router is the node that gathers many 9-1-1 trunks from multiple local end offices and concentrates that traffic, then distributes each call to the appropriate destination—either the correct PSAP via an end office or to an inter-exchange carrier for routing to another area. In other words, it centralizes incoming 9-1-1 traffic and directs it to the right place based on the caller’s location information.

The other options don’t perform this cross-office concentration and routing role: an End Office is the local switch that terminates subscriber lines and handles basic call processing but doesn’t aggregate traffic from multiple offices or route to IECs; an Exchange Area is a geographic grouping rather than a switching node; and a TSP (Toll Service Provider) is a service provider, not the routing switch in a 9-1-1 network.