Enter the last extensions for the ranges of telephone numbers
used on the remote system.
The length of the start and end extensions must agree with the number
shown in the Extension Length field. Leading
zeros might be needed to conform to this requirement. The end extension
must be equal to or greater than the start extension.
Up to 10 different ranges can be specified. AMIS address ranges
and message delivery address ranges must be unique. They cannot
overlap with other AMIS analog networking and/or message delivery
address ranges.