Discussion point: Telco quality?

Fri Oct 9 13:46:13 UTC 1998

Paul Ferguson said:
>
> Funny you should mention this. Actually, aren't most data
> circuits (excluding
> copper pairs into the home) fed into the telco DACS network(s),
> which subsequently
> may be muxed into a fiber infrastructure along with traditional
> TDM voice traffic?
> The DACS network can certainly be an overlay on a fiber
> infrastructure, and usually
> is just that.

I don't recall the exact figure, but something like  50% of US circuits are
on SONET rings. So yes, the voice and data traffic are equally effected.
However, on older non-SONET networks the carriers have a "hot circuit
switch" technology that will switch voice circuits in the event of a fiber
cut.  However, most data circuits do not have such protection.

Private data networks are severly affected by fiber cuts, but the Internet
is less affected because of its own intrinsic self healing protocols.

> Define "reliable".

Good point.  Many carriers and telco manufacturers are coming to the
Internet business saying that we have the knowledge and expertise to build
99.99999+ reliable networks - therefore eventually we are going to take over
the business.  Reliable is easy to define in terms of voice calls.  But it
has whole different set of meanings in the IP world, which most carriers and
telco manufacturers fail to understand.  For example I can have a 99.9999+
SONET network, but if I can't access my DNS root server, then I clearly
don't have a reliable network.

Bill