- From: Henrik Frystyk Nielsen <frystyk@w3.org>
- Date: Sat, 18 Apr 1998 00:38:39 +0900
- To: hardie@thornhill.arc.nasa.gov (Ted Hardie)
- Cc: mogul@pa.dec.com, hardie@nic.nasa.gov, ietf-http-ext@w3.org
At 17:30 04/15/98 -0700, Ted Hardie wrote: >I think the key term in what you write here is "out of band" >agreements; in the previous uses, the end user had some out-of-band >way to know how the proxies in the chain would behave. As is pretty >obvious, that doesn't scale very well, and it doesn't allow anyone >to change the behavior on the fly. Mandatory gives us a chance >to create an in-band method for providing that infomration. The >requirements are different for in-band methods, though, than out >of band methods. Some method of indicating that a Mandatory >header is meant to be consumed by a specific proxy or class >of proxies seems to me to be part of that. Minimally, that >would help deal with situations where a header meant to be >consumed by a proxy isn't. Any knowledge about proxies down the message chain except for the very first proxy is already out-of-band - there is no way a client can get knowledge about the third proxy without out-of-band communication or some extension (which in this context is the same thing). HTTP has two scopes: hop-by-hop and everything else (which may or may not make sense to call end-to-end). Mandatory doesn't (and I believe shouldn't) change this - it just allows applications to express how they extend the message with either of these scopes. Henrik - hop-by-hop which is between an adjacent HTTP client and server. Tunnels do not count as a "hop" as they do not take any part in the communication - everything else which we often call end-to-end. -- Henrik Frystyk Nielsen, World Wide Web Consortium http://www.w3.org/People/Frystyk
Received on Friday, 17 April 1998 11:12:15 UTC