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
phone lines.
Channelized and Unchannelized
T1 Lines
A T1 line may be configured as a single large pipe offering 1.5
Mbps data transport or as 24 individual channels of 64 Kbps each,
ideal for use as individual outside telephone lines to support
Key or PBX business telephone systems.
What Are Pseudowires?
A pseudowire is a virtual "circuit" that emulates a
traditional digital telecom service but on a packet switched network.
MPLS networks are especially suitable for pseudowires. By using
a pseudowire circuit, you can get the point to point connectivity
you desire without having to re-engineer your facilities to accommodate
a different protocol network.
T1 Lines are Full Duplex
T1 lines are bidirectional or full duplex. That means that you
can independently upload and download data at up to the full line
rate of 1.5 Mbps simultaneously. LANs that use switched Ethernet
are also full duplex, but LANs that use hubs operate at half-duplex.
A half-duplex network cannot transmit and receive at the same
time, cutting effective bandwidth by up to half.
How do T1 and DS1 differ?
In general conversation, T1 and DS1 refer to the same thing. But
strictly speaking, T1 refers to a physical line circuit consisting
of 2 pair of copper wires with strict line signal specifications.
DS1 stands for Digital Signal level 1. DS1 is the service level
you get on a T1 line. However, DS1 also is part of the digital
signal hierarchy used in T3 lines and SONET fiber optic carriers.