At 20:18 12/4/2000 +0000, Nick(_dot_)Taptiklis(_at_)gregory(_dot_)co(_dot_)nz
wrote:
>Given that most visually impaired users would likely already have some
>screen reading technology, perhaps the scope of the html->audio might be
>more useful as text augmentation to aid the screen reader?
Just thinking from the point of view of the end user benefits, there seems
to be two broad classes of service - those that could in principle be
performed by client software, and those that can't.
Given existing definitions of the word "proxy" I think we need to be very
careful about wording such as this. A proxy has a client component.
Services that can be local:
services such as transcoding/translation, ad-stripping, and content
resizing, refactoring can all potentially be performed on the client.
Reasons why users may prefer to use proxy-based services include:
Processor power (especially for edge devices - PDA's and the like).
Cost (per use service charge rather than paying for a rarely used
Mongolian<->English translation module).
Remote administration (many people would rather phone their ISP than try
and configure text-voice software themselves).
Admittedly there are scaling benefits, but is remote administration really
something that a proxy-based service might be preferred for rather than on
the "end-user" device? Remote administration of varying types can be
provided on edge systems, though admittedly there is the potential of more
"users" reporting troubles.
Security
Most of these points have been raised elsewhere, but I don't recall
discussion of the benefit of remote administration. For example, many
people have anti-virus software but fail to keep it up to date. Remote
adminstration of software upgrades of virus, transcoding and translating
software would be a compelling benefit for many users (and hence a
product-differentiator for ISPs providing the service).
Of course, the discussion of whether an ISP should do these things (at all)
for their subscribers is largely political, and has taken place on the main
IETF list in the recent past.
That said, I think there are some risks in presenting this model for its
superiority - after all, in order for that to work one needs to be assured
that the traffic flows through an appropriate monitoring device. It's
quite possible that peer-to-peer applications would circumvent the
systems. Perhaps some cautionary text needs to be included when discussing
such systems in the documents?
Proxy-only services:
Services that can in principle only be performed on the proxy include
performance related services such as caching and content-stripping for
low-bandwith connections,
Um, any client can cache. And even on the end of a 9.6kbps wireless link
with on a device with limited memory it can make some sense to cache on the
device rather than on the proxy, even when that proxy is only be 1 hop away.
and services that provide users with information
not available otherwise - for example a search engine on locally cached
pages could be enhanced by modifying the search field on popular search
engines to a drop-down box displaying recently used key words (with
obvious privacy caveats).