[e2e] Is a non-TCP solution dead?

[Injong Rhee]

Hans,

I don't think we are disagreeing here. I was just commenting on
link-level solutions; maybe I should refer it to be an application-layer
solution rather than e2e. Yes. Use of proxy might be necessary when the
servers are sitting outside the managed networks. No argument there. 

Injong


-----Original Message-----
From: end2end-interest-admin at postel.org
[mailto:end2end-interest-admin at postel.org] On Behalf Of Hans Kruse
Sent: Monday, March 31, 2003 5:31 PM
To: end2end-interest at postel.org
Subject: RE: [e2e] Is a non-TCP solution dead? 

Injong,

the problem here is the definition of "e2e".  Several others have 
summarized the PILC work better than I could -- the short answer is that

you either contain the application within the carriers network (as you 
imply below) _always_, or you allow at least some access to the Internet
in 
general.  The former is not really e2e unless you consider the 
carrier-internal network as the entire information universe for the
mobile 
users.

What you cannot do is let your non-TCP, or modified TCP, flows exit into

the internet at large.  So,  if general e2e access to at least some of
the 
internet is the ultimate goal, you have to use proxies (which have
limited 
benefit in many cases) or engineer the link layer for TCP use (which is 
what PILC advocates).

--On Monday, March 31, 2003 16:00 -0500 Injong Rhee <rhee at eos.ncsu.edu> 
wrote:

> But in the absence of deployed solutions for link-layer or MAC
protocol
> (it takes time carriers to update them after they put it so much money
> into the current infra), link-level solutions are really out of reach
> for application developers.
>
> Another point I want to make is that the servers are typically located
> within carrier's managed networks. In this case, the wired line
problems
> are less likely and most of problems we experience are wireless line
> problems. In the case, some e2e can be a good alternative.
>
> Injong
>
> -----Original Message-----
> From: end2end-interest-admin at postel.org
> [mailto:end2end-interest-admin at postel.org] On Behalf Of Hari
> Balakrishnan
> Sent: Monday, March 31, 2003 3:05 PM
> To: Spencer Dawkins
> Cc: end2end-interest at postel.org
> Subject: Re: [e2e] Is a non-TCP solution dead?
>
>
> TCP over wireless has been an area of active work for a while.  It
seems
> to be
> generally true that good local recovery solutions perform pretty well
> and I
> haven't seen any end-to-end solution that performs as well as good
local
>
> optimizations.
>
> Even if there were reasonable end-to-end solutions, from an
> architectural
> standpoint it seems to me to be a mistake to try and deal with
wireless
> vagaries as an end-to-end problem.  In my opinion, well-designed
> link-layer and
> MAC protocols are the way to go.
>
> Hari
>



Hans Kruse, Associate Professor
J. Warren McClure School of Communication Systems Management
Adjunct Associate Professor of Electrical Engineering and Computer
Science
Ohio University, Athens, OH, 45701
740-593-4891 voice, 740-593-4889 fax