T1 vs DSL for Business Broadband
T1 lines set up as T1 Dedicated Internet connections give business
users guaranteed bandwidth of 1.5 Mbps both upload and download,
plus a SLA service level agreement to assure line reliability.
DSL is a "best effort" Internet service that is offered
without any service guarantee on a shared connection. Bandwidth
varies depending on how heavily other businesses are using the
Channelized and Unchannelized
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 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.
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