On Sun, 14 Feb 1999, ccrobins wrote:
> How is everybody doing on this? I bought a 56K v.90 MODEM and the
> best it ever gets on at is 493000. Spld another identical MODEM to my
> neighbor lady and it never gets on at better than 48000.
Oh boy, talk about off topic! I'll probably catch hell from someone for
replying, but it's something that probably affects a lot of you. I'm an
ISP, so I deal with this question every day...
Assuming your ISP has V.90 modems at his end, then 56,000 bps is the
maximum possible connection speed you can theoretically get. That doesn't
mean you should expect 56K connections. In fact you will never see a 56K
connection, and if you really are getting 49,333 bps then you are
extremely lucky. Very few V.90 users ever see that speed. The average,
according to industry surveys, is in the 44,000 - 48,000 bps range.
When two modems connect they negotiate a connection speed that is reliable
under the conditions they find on the phone line at the time, and/or a
speed that is workable given the level of compatibility of the two modems
involved. Once that initial connect speed is established, the modems
renegotiate constantly to adjust to changes in phone line condition. What
your dialer software reports is the initial connect speed, but the speed
actually changes constantly during the course of your online session.
Any number of phone line conditions can prevent you from getting
connections as fast as you might like, but line noise is the biggest
culprit. If you are on a noisey line, then your modem and the ISP's modem
will negotiate a slower speed to compensate for the interference caused by
the noise. In the case of a 56K modem, if there is more than one analog
to digital conversion between you and the ISP, or if the distance between
you and the local switching office for your telephone exchane is too
great, then 56K connections will be impossible and you will be limited to
V.34 (33.6) connections. If noise is the problem, you may be able to get
your local telco to fix it. If too many analog to digital conversions or
too great a distance is the problem, then you're out of luck.
The other major issue at this stage of V.90 development is incompatability
between modems. True, V.90 is an industrywide standard, but the modem
manufacturers are still trying to figure it out. The result is minor
incompatabilities between modems from different manufacturers. To
overcome this, most V.90 manufacturers are releasing new versions of their
firmware all the time. If you want to play the V.90 game successfully,
you must be willing to upgrade your modem firmware every time the
manufacturer releases a new version. Even then there are no guarantees,
but the situation is improving steadily.
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Chip Old 1948 M.G. TC TC6710 NEMGTR #2271
Cub Hill, Maryland 1962 Triumph TR4 CT3154LO
fold@bcpl.net
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