To help this along, NW is used for overflow trunkgroups, thus giving a peaked traffic pattern. If we look at voice traffic and the models, we would have to choose on a few factors:
call arrival pattern
blocked call disposition
blocking factor
Traffic Load
Each of these factors will help us choose a traffic model.
NW model shows peaked arrival pattern, blocked calls retried, etc…
EEB shows random arrival pattern, blocked calls retried, etc…