🚀 go-pugleaf

Mitre <mitre@netcomuk.co.uk> wrote:
: >The problem is not the technology (i,e. whether its ISP with internet
: >router at the other end or just a humble modem) the problem remains is
: >that modem connections do remain open for much longer than normal calls
: >*especially* if the call is free. In fact as it requires no action on
: >your part to keep a line open there is even probably an incentive not
: >to drop the line. Telcos in the US are having to spend millions of
: >dollars at the moment to increase their switching capacity because of
: >this.

: This same company will however be trying in the next year or so to
: sell cable modem lines running at 1-10MB/s. However if they can't
: withstand the traffic from 28.8 modems with their fibre optic lines
: then they shouldn't be in business.

Cable modems, I believe, use the the cable rather like an ethernet with
the total bandwidth being shared by whoever is connected. This will be
connected at the cable head end by dedicated equipment installed for
this. Also a cable modem session will, I think, only be using bandwidth
when actually transfering data - and any bandwidth problems will be
limited to this and not affect normal telephony calls.

Modem connections route out into the same switching infrastructure as
used by normal telephone calls. A modem session ties up one line 
through that switch for the entirity of the connection. This is the key
difference.

I expect that TW would be quite happy for someone to leave a cable
modem connection up semi-permantently which was idle for most of the
time as it is not consuming any resources. However keeping a modem
connection open semi-permanently is definitely reducing the swicthing
bandwidth by 1 line.

People switching the cable for phone services expect that when they
pick up their phone they get a dial tone and can make a call. There are
areas in the US where, I've read, this is now no longer always  the
case as the increase in calls and call durations due to  people having
long modem sessions on free local calls means that the switching
capacity that was sufficient for call patterns 2 or 3 years ago is no
longer sufficient. As a result millions are being spent increasing this
and this cost clearly will be passed on to the consumer.



-- 
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                              david shepherd
 SGS-THOMSON Microelectronics Ltd, 1000 aztec west, bristol bs12 4sq, u.k.
        tel/fax: +44 1454 611522/617910  email: des@bristol.st.com      
      "whatever you don't want, you don't want negative advertising"