Why doesn't BGP... -Reply

Connectionless and Connection oriented both refer to packet switched
technologies, whereas the phone company uses circuit switched technology.

Yes, this is absolutely correct.

Circuit switched means that the same wires/timeslots are dedicated to
a call from the time it starts until the time it finishes.If you do
not speak, the wires are idle/wasted. I am sure you understand packet
switching. In a packet switched network, connectionless means that each
packet has no state information, and stands alone, in the IP world we call
this UDP. Connection oriented would be the equivalent of telnet or
some other TCP service.

This is a terminological question. Here the talk was about connectionless
and connection-oriented _network_ layer; not the transport layer.

The connection-oriented packet routing network is a generalized case
of circuit switching -- you can multiplex connections differently.

The fundamental difference between connectionless and connection-oriented
networks is the amount of state necessarily kept by gateways in order
to perform forwarding of the bits. A gateway of a connectionless network
has only to keep the traffic-independent topological information (this
definition is more generic than just next-hop routing; it includes
source-based routing, semi-flows, etc). A gateway of a connection-oriented
network has to keep the topological information (in order to be able
to route connections) and the traffic-dependent table of connections.

BTW, by that definition an IP network which supports RSVP _is_ a connection
oriented network.

If gateway has state which is modified by traffic, that state must
necessarily grow with the traffic; in Internet case, exponentially
and at the rate far exceeding Moore law's.

SS7 (Signalling System 7) is a connectionless packet switched technology
used to control the setup and teardown of circuit switched calls.
Originally is was used as a database query technology to make 800
numbers portable across carriers. If this did not make sense I can descibe
it in a little mnore detail offline.

At least that telcos got right.