DS3, T3 and T1
What is the difference between DS3
and T3? Both of these terms originate
in the T-carrier system. This system was originally developed to provide
high-speed trunk lines between telephone company offices. Everything
is based on DS0 or digital signal level zero, which is a 64K bit per
second channel. Group 24 DS0 channels together and you have a DS1.
Another aspect of the system is that if the DS1 is connected to a wire circuit,
it is called a T1. T1 runs at 1.544 Mbps. If your business class DSL or T1 broadband
service no longer has enough speed to meet your bandwidth needs for video or
data transfer, you may be considering a move up to DS3
or T3 service. In addition,
you can get an instant online quote if you will be so kind as to tell us where
you want the service located, and provide some basic contact information so we
can help you pick the optimum service for your business from available vendors
in your area.
T3 is the big daddy of the T-carrier system. T3 is copper wire based, although
using coaxial cable rather than pairs of phone wires to support the higher speed.
OC-3 is another animal entirely. It is part of the Optical Carrier (OC) levels
defined for a fiber optic transmission system called SONET (Synchronous Optical
Network). OC-3 runs at 155 Mbps verses T3 at 45 Mbps. That is a big difference
in speed and, as you might imagine, cost. If you group 28 DS1 channels together
and you have a DS3 or digital signal level 3 running at 44.736 Mbps, or 45 Mbps
for short. Connect that to a wire circuit and its called a T3. By the way, that
T3 line is equivalent to 672 voice channels. DS3 and T3 terms are used interchangeably.
OC-1 service is the equivalent of DS3 or T3.
They provide 672 voice channels or telephone lines. They run at 52 Mbps to include
the extra bits needed for the optical service. The highest OC level you can get
at present is OC-768, which runs at 39,512 Mbps or about 40 Gbps. If all you
require is 2 or 3 times the speed of a T1 line, then you are better off with
multiple T1 lines or connecting them together in what is called bonded T1 service.
Once you get past 6 or 8 T1 lines, the price of a T3 line is often competitive.
DS3
transport may be a cost effective substitute for point to point microwave for
MPEG Broadcast Video Transmission. It is also applicable for Surveillance Cameras,
CCTV Systems, and VLAN Trunks. If a full DS3 line is more bandwidth than you
really need, it is also possible to get Fractional DS3, which gives you a portion
of full DS3 bandwidth at a lower cost. Of course, DS3 is also available in multiples
to increase bandwidth, similar to bonded T1 service. DS3 Bandwidth generally
makes sense for corporations that have a need for high speed electronic data
transfer between plant sites or offices. Very large call centers, enterprise
wide VoIP and IP PBX systems, Internet service providers, universities, research
labs, video conference centers and software development companies are also good
candidates for T3 lines with DS3 level service.
