In a CAS network, systems can function either as branches or as the main location. A branch can connect to only one main location.

CAS reduces the number of attendants that are required at a branch. For example, a chain of department stores can have a centralized attendant at the main store to handle calls for all of the branch stores.

A branch can have an attendant. Access to the branch attendant must be by way of an individual attendant extension. Incoming trunk calls in a CAS network can bypass branch attendants. The centralized attendant can route these incoming trunk calls back to the branch attendant.

Branch calls terminate on the CAS main system based day-destination or night-service destination of the incoming RLT trunk group. An attendant console might not always answer or extend incoming CAS calls.

If someone other than an attendant answers a CAS call, that person can either press the Flash button on a multiappearance telephone, or flash the switch hook on a single-line telephone, to extend the call back to the branch. The branch reaction to flash signals and the branch application of tones is the same whether an attendant, or someone other than an attendant, answers or extends the call.

If an extended call returns unanswered to the main attendant, the called party at the branch does not drop. The called party at the branch continues to be alerted until the caller releases. Using this process, the attendant can talk to the caller, and then extend the call again, if the caller wants, without redialing the number.

If an extended CAS call recall times out and goes to coverage, but is unanswered, the branch leaves the extended-to party ringing. The system drops coverage.

When an analog telephone call goes to coverage, the call is dropped. This process is the exception to the branch leaving the extended-to party ringing. If the main attendant extends a call to an analog telephone, and that call goes to coverage and later returns to the main attendant, the call is treated as an incoming LDN call. If the user requests, the attendant must extend the call again.

On an incoming CAS call to the main attendant, the system displays the Name field from the Trunk Group screen for that RLT to the attendant. Therefore, you must administer the Name field on the Trunk Group screen to provide meaningful branch identification information.

The Music-on-Hold feature at a branch applies to two stages of LDN calls: during call extension, and when the call is on Remote Hold.