TCP Over Satellite BOF (tcpsat)

Thursday, April 10 at 0900-1130
Friday, April 11 at 0900-1130
===============================

DESCRIPTION:

Satellites are being used to extend the Global Interenet 
geographically and will be more ubiquitous in the next decade 
with the deployment of several proposed services capable of 
providing greater than T1 access to individual users anywhere 
in the world.

Yet, satellite links have a unique combination of 
characteristics that can affect the throughput of TCP traffic. 
Because of the high-bandwidth delay product, slow start and 
congestion control algorithms behave much differently when 
the path includes a satellite link than exclusively terrestrial 
ones.

This BOF will present some of the research that has been 
done to characterize this behavior and suggest creation of a 
short lived working group to sort out the issues into those 
which require more research and those which can be 
addressed through a combination of implementation and 
protocol solutions.

BOF Goals:

Build a consensus to create a working group that will have a 
very short lifetime (1-2 meetings). This working group will have 
as its charter to produce an informational draft (ID).

This ID shall describe the issues affecting improved TCP 
throughput over satellite links. Issues that should be addressed 
are the high delay-bandwidth product and the high 
propagation delay between routers because they are the 
primary issues affecting throughput. Other issues identified by 
the working group may be included as well.

The document should identify implementation factors that 
affect throughput as well as protocol factors. Standards track 
protocol changes or options as well as acknowledged best 
practices should be identified where they improve throughput.

The ID should have a section on additional requirements and 
open problems. This section could include pointers to 
organizations/companies that are willing to donate satellite 
resources to collaborate in this research.


The BOF will meet twice during the Memphis IETF. The first 
meeting will address the items below and the second meeting 
will be to start work on the I-D.

AGENDA

INTRODUCTION (10 min)

ISSUES SUMMARY (1-2 presentations) (one hour)

       Briefing One:  Current view of the problem domain
       Tim Shepard, BBN

          - This is our environment(s)
          - These are the symptoms of our problem
          - We think these are the biggest contributing factors
          - Identification of similar communities of interest
          - These are some solutions that have been proposed to date
          - Rhetorical question (until discussion time): What have we overlooking?


       Briefing Two:  Phased Solutions 
       Shawn Osterman, Ohio Univ.

          - We need an "environmentally friendly" solution now
          - This is what we can do today (mostly architectural)
          - This is what we think is possible in the near term
            (IETF timespan of a Working Group) to influence existing
            and standards track protocols
          - Ultimately, it would be nice if...
          - What are we missing/overlooking here?


DISCUSSION OF THE PROPOSED CHARTER (45 min) 

DRAFT CHARTER PROPOSAL

The TCP over Satellite Working Group is chartered to produce an 
informational draft which describes the issues affecting TCP througput 
over satellite links. It identifies the domains in which each issue applies; 
fixes, both protocol and implementation, that ameliorate reduced 
throughput; and areas for further research. 

This group will meet at two IETFs and will present the final ID for review at 
[the IETF meeting following Germany].


DISCUSSION TOPICS:
   - Feedback on the problem space
     o Factors that have been overlooked
     o Identified factors that might not be relevant

   - Discussion on proposed solutions & identification of other
     possibilities
     o How feasible are they 
	(i.e, are there "server-side" only solutions)
     o How civic minded are the fixes 
	(do they work and play well with others?)

   - Discussion on how to demonstrate that a candidate solution(s)
     will not be detrimental to the larger community
     o I don't think that a simulation/emulation only approach 
       will cut it.

ADJOURN

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