At 23:45 05/04/03, The Purple Streak, Hilarie Orman wrote:
The Minitel/Internet example is certainly interesting. I think that it is
useful to keep the architectural separation between transport and
application in mind here.
Good example of OPES service: Minitel page <-> HTML page
question: is there a cache of translated pages at the gateway?
Good example of OPES service: English -> French
question: are French network service providers allowed to translate
French -> English :-)
Good example why OPES has privacy requirements: removing privacy-related
information from data going to callout servers. I don't know what kind
information X.25 carries or whether or how hard it is to remove/restore
it, but the overall principle is an important one
Example of service on an generalized OPES architecture: X.25 <-> TCP/IP
question: this raises a lot of questions about addressing, flow control,
naming, character set conversions, etc. Seems like a
nightmare, ..., does it really work? It would seem especially
awkward to support the barely disguised OPES model of forwarding
IP packets on the callout path - it's not a requirement, but
it certainly works well in an all TCP/IP environment.
Well, there are certainly a lot of issues here and it could be much
application dependant (TCP/IP). Only a test can show what is the fastest.
Also depends on the Window size, etc. But the real point is that it shows a
totally different logical model and a different philiosophy of protocol. We
have a fast pipe with bypasses and loops.
And no callout protocol.