Why doesn't BGP... -Reply

Sun Nov 17 12:05:29 UTC 1996

> Larry J. Plato <ljp at ans.net> wrote:
> 
> >Connectionless and Connection oriented both refer to packet switched
> >technologies, whereas the phone company uses circuit switched technology.
...
> 
> 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
...

> >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.
> 

Vadim makes my point better than I did - SS7 etc. make their routing
decision OTO once per call (on call setup). IP makes it once per packet.
Therefore you can put a lot more effort into finding the correct route
if you only have to perform the calculation once. This was an algorthmic
point not a network/transport layer point.

Alex Bligh
Xara Networks