Facsimile: 321**1234 & Cellular: 321##1234.
Consider again all of the various telecommunication
devices commonly being accessed by telephone lines: telephones, facsimile
machins, cellular phones, modems and pagers. These devices can now be assigned
a specific marker that would be fixed for each such device.
If our salesman has a laptop computer,
which increasingly has become a competitive necessity, his modem sub-address
would be 321*#1234: very convenient and most expedient, as would
a pager with 321#*1234.
Essentially, the salesman's five lines
function independently because each has a separate and distinct line number,
however their sub-addresses are simply expected variations on the primary
All sub-address lines operate autonomously
and as required simultaneously.
6. SIGNALING AND CONTROL