Look-Ahead Interflow Considerations

is being implemented via a route-to digits command, the route-to digits command fails, and vector processing continues at the next step, which should be a default treatment.

■It may be prudent to take steps in case a route-toattendant command fails, such as providing a disconnect announcement.

■From time to time, all of the system’s touch-tone receivers might be in use. As a result, you should avoid starting your main vector with a collect digits command, since the caller on a DID or tie trunk in this case receives no audible feedback if he or she has to wait for a receiver to become available. Accordingly, it is a good practice to include some treatment (for example, a wait-time 0 seconds hearing ringback step) before the initial collect digits step.

The following are considerations you should keep in mind when working with Look-Ahead Interflow:

■Never interflow to a remote vector that in turn might interflow back to the same local vector. This could cause a single call to use up all available trunks.

■The oldest-call-waittest condition should not be used in LAI vectors. OCW corresponds to the very next call to be answered and, as such, this test condition gives no information on the current state of call overload (for example, if OCW = 30 seconds, all we know from this is that the queue was overloaded 30 seconds ago). In place of oldest-call-wait, use the EWT conditional. See "Expected Wait Time (EWT)" on page 6-2.

■If an LAI call attempt is accepted by a step that contains a queue-to main, check-backup split, or route-tocommand, there is a small but finite interval during which the call could be answered by an agent at the sending switch before notification of ‘‘acceptance’’ is received by the sending switch. In this case, the caller would be connected to the agent at the sending switch, while the agent at the receiving switch might receive a ‘‘phantom’’ call.For this reason, you should consider using a short wait-timeor announcement step at the receiving switch to allow the call to be accepted and taken out of queue at the sending switch. If call acceptance is to be based on available agents, use of a wait-time> 0 seconds or an announcement is not recommended. A wait-timewith 0 seconds of silence might be useful in this case.

■When an LAI call attempt is made, the TTR (if attached) is disconnected, and any dial-ahead digits are discarded. This implies that a subsequent collect digits command would require that the TTR be connected.

■Be sure the feedback provided by the receiving switch after a successful LAI attempt is consistent with what the caller has already received.

Issue 4 September 1995 C-3