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On Wednesday 26 February 2003 11:46, Elliotte Rusty Harold wrote:
> At 11:30 PM +0000 2/25/03, Alaric B. Snell wrote:
> >LDAP, SNMP, SSL, the phone network... nah, none of those interoperate very
> >well, do they? And I bet XML carries *way* more traffic than the *phone
> >network*, so it couldn't *posisbly* be interoperably transferring less
> > data from day to day than ASN.1 systems :-)
> It strikes me that the phone network, when used to transfer voice, is
> essentially an analog system. Yes, there's a lot of conversion to
> digital as soon as you get past the local office, or maybe even
> sooner nowadays with VOIP. But it's still about an analog signal
> going in one end of the connection and an analog signal coming out
> the other. That makes it more resistance to corruption than digital
> computer networks where every last byte often needs to get there
> unaltered in the right order.
Many calls through it are purely digital too, but the phone signal is just
the payload here - like the CDATA in XML. I'm interested in the framing, the
fact that you request services from your phone keypad, from the basic dialing
to putting calls on hold and so on.
> Even more importantly, the signal is analog and interpreted by humans
> rather than computers (most of the time). Humans deal a lot better
> with noisy data. They can fill dropped words and degraded signals far
> beyond what computers can handle. This also makes the phone network
> far more robust in practice.
More and more of the traffic on the phone network is IP over PPP :-) But I'm
really more interested in the control interfaces to the phone system itself -
the voice is just payload.
> However, XML isn't designed to solve these problems. XML works in
> the much tougher domain of enabling computer-to-computer
> communication. It's harder for two computers to talk to and
> understand each other than two people.
But the phone network is made of computers. For every international phone
call, lots of computers, made by different companies, running under different
administrations in different cultures indifferent countries, talking over
various different interconnects, conspire to create the illusion of a call
A city is like a large, complex, rabbit