Sharing Business Broadband
Costs
Even smaller businesses can have high performance dedicated Internet
access by splitting the cost of a T1 line with other businesses
in their building or business park.
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.
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
Backhaul
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.