Re: News Tidbits

Ron Resnick (
Thu, 29 May 1997 12:00:20 +0300 (EET DST)

Interesting find. But I'm confused..

How can a modem on a conventional analog line deliver 67 kbps, when
a POTS channel is 64k, of which 8 is consumed overhead for signalling,
leaving an effective 56k channel? Isn't that exactly what ISDN is
about - to give you a 'broadband' linecard in the switch that overcomes
the 56k boundary? Even if you do phenomenal compression on the line
between the modem and the linecard, if the switch-side of the linecard
is 56k, isn't that the hard upper bound on what you can get out of POTS?
If so, what is this 67k?

Anybody out there can help me with my elementary information theory foibles?

> *** Transend delivers 67 kbps modem
> Transend Corporation advanced modem speeds to new heights, without the
> need for digital connections at either end, with their announcement
> Tuesday of the Transend Sixty-Seven, delivering speeds of 67 kbps both
> upstream and downstream, over existing analog phone lines. The
> Transend 67 solves the increasing speed and bandwidth problems of
> present-day Internet users, while utilizing the existing ubiquitous
> analog network. The Transend 67 also makes widespread, economical
> video teleconferencing possible for all sizes of companies. For full
> story, see
> *** New single-chip, fast ethernet transceiver sets new standards
> Level One Communications Inc., a developer of Ethernet IC
> communications technology, announced Tuesday a breakthrough in Fast
> Ethernet performance. The company introduced a flexible 10/100-TX
> single-chip CMOS Ethernet transceiver that operates at distances in
> excess of 140 meters and can also be designed into 100BASE-FX fiber
> equipment. The new LXT970 Fast Ethernet transceiver supports standard
> Ethernet (CSMA/CD) and full-duplex operation at 10 Mbps and 100 Mbps.
> Unlike other 10/100 Ethernet transceivers, the LXT970 includes a
> fiber-compatible, ECL-type interface for use with 100BASE-FX networks.
> See
> -
> There is no off position on the genius switch. ...David Letterman
> <> <>