T1 PRI For PBX Telephony
A T1 PRI, also called an ISDN PRI, is a "Primary Rate Interface"
providing 23 individual digitized telephone lines plus data such
as Caller ID on a single digital telephone trunk line. A PRI line
is usually much less expensive than a dozen or more analog business
Digital Signage Bandwidth Options
Digital signs, including large billboards, are easily and instantly
updated with data downloads. T1 and fractional T1 lines or VSAT
digital satellite connections are available even in rural areas.
Channelized T1 vs ISDN PRI
T1 lines can support two protocols of switched circuit telephony.
Channelized T1 lines offer 24 phone lines using in-band signaling.
ISDN PRI, or Primary Rate Interface, offers 23 phone lines and
common channel signaling that can include data such as ANI Automatic
Number Identification or Caller ID.
T1 and T3 Lines for Wireless
A WISP or Wireless Internet Service Provider needs a way to connect
the Internet to the tower radios. T1 lines and bonded T1 lines
are widely used for this purpose, as well as cellular tower backhaul,
because of their almost universal availability. T3 lines offer
28x the bandwidth of T1 lines but are typically more available
in larger metropolitan areas.
T1 Line Bandwidth Explained
A T1 line is typically referred to as having a bandwidth of 1.5
Mbps. The precise line speed is 1.544 Mbps. However, the usable
bandwidth or payload is actually 1.536 Mbps. The difference is
8 Kbps which is used for line framing to keep the transmitting
and receiving ends of the circuit in synchronization.