Apologies for the delay in responding. I believe that Mark's summary is
pretty accurate but I would add one clarification. SOAP encompasses much
broader scope that iCAP. SOAP is a whole architecture for messaging; iCAP
is a very simplified vectoring protocol.
iCAP is a way of getting an object X from A to B. Specifically it does not
define how this decision is made - it is simply defines the protocol by
which the content is transferred.
iCAP shares a lot more functionality with CVP than SOAP. (In fact, the
original work for iCAP was titled Simplified HTTP Vectoring Protocol).
Rgds,
John
At 04:15 PM 25/06/01 -0700, Mark Nottingham wrote:
In a nutshell:
ICAP is a means of encapsulating HTTP inside of HTTP, to allow
messages to be 'vectored' from an intermediary to an ICAP server for
processing, and then sent on their way. It also defines where those
messages may be vectored from the intermediary. I believe that its
primary design goal is efficiency, but that's different depending on
who you talk to.
SOAP can IMHO best be thought of as an XML messaging convention, with
some protocol-like attributes (such as the RPC convention). SOAP is
designed to be transport-dependant; while its most common use is
across HTTP, it can be used with other underlying protocols like SMTP
or raw TCP. SOAP is designed to allow targetting of blocks of the XML
to be processed by specific intermediaries. Its primary use cases are
'Web Services', i.e., the machine-machine Web, e.g., stock quote
services, order queuing, etc.
So, SOAP could be used to implement ICAP, but then again so could
BEEP. Not too many of the ICAP people are interested in using SOAP,
though, as their requirement is to allow 'wire-speed' vectoring and
processing, and they find the overhead of XML unacceptable.
Cheers,
On Mon, Jun 25, 2001 at 04:11:01PM +0800, Wanghong Yuan wrote:
HI, All
Where can I find some materials or dicussion on ICAP and SOAP? I think
both of them address somewhat the content adapation problem in Internet.
Thanks.
Wanghong
Speaking for myself,
--
Mark Nottingham, Research Scientist
Akamai Technologies (San Mateo, CA USA)
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