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
Bonding T1 Lines for Higher
While a standard T1 line provides 1.5 Mbps upload and download
bandwidth, lines can be bonded to create total bandwidths of 3
Mbps, 4.5 Mbps, 6 Mbps, 7.5 Mbps, 9 Mbps, 10.5 Mbps and 12 Mbps.
An advantage T1 lines have over fiber optic connections is that
they are available nearly everywhere without special construction.
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 Digital Cross Connect Systems
A digital cross connect system, often abbreviated DCS or DCAS,
allows you to switch traffic among your T1 lines. It will even
reach into the line to connect individual channels or timeslots
rather than the entire circuit. A manual device that cross connects
T1 lines is called a DCX or patch panel.
T-Carriers Offer Digital Telephony
T-Carriers, which include both T1 and T3 lines, offer digital
telephone trunking with multiple phone calls on a single physical
circuit. T1 lines can support up to 24 simultaneous phone calls.
T3 lines have 28 times the bandwidth of T1 lines and can offer
up to 672 simultaneous phone calls for large enterprise or call