Note:
Because the V.92 modem standard was so new when we went
to print, and because there are basically no major
implementations among leading ISPs yet, most of the
information in this next section is based on V.90 modems. V.92
modems should offer faster upload speed, quicker call setup
and handshake negotiations, as well as on hold support for
Internet call waiting. It remains to be seen whether any of
these benefits ever reach mass market.
Can Only Go So Fast Without a Digital Line on Receiving End
The only way you’ll ever get anywhere near
that 53.3Kbps download speed is by dialing into a modem that has a
digital connection (i.e. a T1 line or something similar) to the
local telephone company’s central office (“CO”).
This means, if you have an analog modem on your
home computer and you’re connecting to an analog modem in your
office, you’ll never surpass 33.6Kbps connection speeds unless
your office has some kind of digital line to the local telephone
company’s central office.
You generally can connect to your ISP at speeds
between 33.6Kbps and 53.3Kbps because your ISP leases digital lines
from the local telephone company.
Geography: Phone Wiring Beyond Your Control
What else influences your analog connection
speed?
The distance between your location and your
telephone company’s central office is a major determinant
in your connection speed with an analog modem.
An office that’s only 500 feet from the
telephone company’s central office will, other things being equal,
get a much better connection speed than an office that’s 5,000
feet or more from the telephone company’s central office. Short of
relocating your office down the road, there’s not much you can do
about this.
Note:
Your office’s distance to the local telephone company central
office is also a major determinant of whether your company
qualifies for high-speed DSL-based Internet access.
What You Can Control: Inside Phone Wiring
However, you do have some control over
conditions once the telephone cabling enters your office --
what’s known in the telecommunications industry as inside
wiring.
Try to minimize the distance between the
location telephone service enters your office and your modem
telephone jacks. This point of entry is often referred to as your
network interface device (NID) or demarcation point (demarc).
Also, make sure there are no in-line splices or
obviously poor cabling conditions between your NID and modem
telephone jack.
Finally, make sure the connections on the NID
and your modem telephone jack are secure and properly terminated.
You often can get an immediate improvement in modem speed by having
these connections rechecked and reterminated (known by techies as
“punching down” the cable).
Tip:
In many locations, the local telephone company no longer has a
monopoly over inside wiring. Regardless of whether your small
business has authority over your inside telephone cabling or your
landlord takes care of it, most telephone system resellers and
electricians now routinely get involved in installing category 5
and category 3 copper cabling. This competition often can mean
lower prices and better service. Some small businesses and
homeowners now even do a limited amount of their own inside
telephone cabling.
Phone Wiring Action Items
What range of connection speeds are you
able to get from analog modems in your office? Are some days, or
times of day, better than others?
Are most of the modems your company owns
based on the newer V.90 and V.92 standards for 56Kbps modems?
Does your company have a digital connection
to your local telephone company (i.e. some kind of T1/T3 or leased
line)?
Do you know how many feet (or meters) your
office is away from your local telephone company's central office?
(Note, this isn't driving distance. This is the distance that the
copper and/or fiber optic cabling travels. Your local telephone
company should be able to supply you with this information.)
Do you know where the telephone company
terminates its service in your office through its network interface
device (NID)?
Do you have a rough idea of how inside
telephone wiring runs from the NID to individual modem jacks?
Are you aware of any in-line splices, or
otherwise poor cabling conditions, that can be rewired into home
runs to the NID to improve the likelihood of greater modem speed and
reliability?
If you move a PC and modem combination from one modem jack in your
office to another, does dial-up modem performance improve? What
about if you relocate the PC and modem combination to a modem jack
immediately adjacent to the NID? (If either of these improves modem
performance, you've found some relatively inexpensive ways to boost
performance and reliability.)
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