The Routing Over Large Clouds Mailing List Archive by date

[schulter@zk3.dec.com]

> If the "real client" is an NBMA-attached host,

Hmmm.  Well, the "real client", as Grenville points out, is actually the user 
isn't it?  Regardless of what information the host/network is able to gather 
about the cost of a particular call, it should be up to the user to decide if 
each long-distance call should be placed (or any call that will incur any 
charge over and above the local call to the default router).  This decision 
would be based entirely on how much a user is willing to pay to access certain 
content or services.  Each user will have a different cost/benifit ratio for 
different content.  So I would think each user would want to know how much a 
call would cost, and be given the chance to decide if the cost is worth it for 
the target content or service.  The computer can't make this decision since 
this is really a value (quite literally) judgement.  There's also an issue of 
call volume even if the per-call cost is low (1000 HTML links per month 
resulting in long  distance calls at $0.20/call is rather significant). How 
do we expect users to manage this?

Would this mean something like a pop-up dialog window for each possible
connection (like on every click on an HTML link)?  Very annoying.  I'm sure
other possibly less annoying ways to handle this could be developed, 
but I think it would still be rather hard to manage.  And of course, 
cut-through of any type would have to be disabled when your 9 year-old was 
using your PC ;-)

> If the "real client" is, say, an Ethernet-attached host and there's a
> router between the Ethernet and the NBMA network, then it's not clear
> to me how the router can communicate "cost" information to the host,
> but whatever method is used would seem to be independent of NHRP.

Well then, maybe it's the owner of the edge device that would make this
decision.  I would guess that the owner of the directly connected device would 
be the one that would be billed.  My guess is that the owner would want to pass
these costs back to the individual users, so now the "cut-through" decision
is even more difficult to deal with (economically).  Do we now want routers
and edge devices to deal with accounting? Or if not, then would the owner
of the edge device want to incur any expenses that couldn't be properly
passed on to the consumers?  If there is no clean way to bill this, I
not sure if any owner of an edge device would ever allow the edge device
to do cut-through.

Finally, all this is very different than the current Internet model.  Users
don't have to worry about these things now, so why should they have to
worry about them in the future?  My ISP rents bandwidth to his ISP for a flat 
rate and distributes the cost of that bandwidth to his users. I pay a flat 
rate every month to my ISP, a flat local call rate to NYNEX, and I don't have 
to worry about how much each click on a hypertext link is going to cost me.
I can Internet to my heart's content knowing I will pay only the flat rate. 
It's pretty much the same here at work.  I imagine Digital pays a flat leased 
line rate too.  IMHO, this is exactly the model we should maintain for ATM. 
I don't think cut-through maintains this model and introduces too many costs
and too much complexity for something very few people will be able to 
afford to use (until the day when I can get unlimited long distance 
calling from AT&T/MCI/SPRINT for $20/month).

Now cut-through on a private (local or campus) net is a different issue.

 --- pete

------------------
Peter Schulter					schulter@zk3.dec.com
Digital UNIX Networking				voice (603) 881-2920
Digital Equipment Corp				voice (DTN) 381-2920
ZK3-03/U14					FAX   (603) 881-2257
110 Spit Brook Road				FAX   (DTN) 381-2257
Nashua, NH 03062