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Re: pilc minutes for IETF 48

From: James P. Salsman <bovik@best.com>
Date: Mon, 18 Sep 2000 20:08:26 -0700 (PDT)
Message-Id: <200009190308.UAA13157@shell9.ba.best.com>
To: pilc@grc.nasa.gov, Reiner.Ludwig@Ericsson.com
Cc: discuss@apps.ietf.org, ietf-mmms@imc.org, ietf@ietf.org
Reiner,

Thanks for your reply:

>>...  There seems to be a lack of understanding about the
>> parameters involved, and most if not all of the important ones are
>> at least touched on in the DoCoMo I-D and the documents it cites.
>
> You need to be more precise. Which parameters are you talking about?

These from http://search.ietf.org/internet-drafts/draft-inamura-docomo-00.txt

     Feature        Parameter/Recommendation  RFC/Status
     -------------------------------------------------------------------
     MTU size              1500B              N/A
     Window size           64KB               RFC 793  Standard
     Initial window        2 mss              RFC 2581 Proposed Standard
     Initial window        up to 4380B        RFC 2414 Experimental
     Use of SACK           Recommend          RFC 2018 Proposed Standard

So, given the ECN-like properties of Radio Link Control -- 3G TS 25.322; 
which also seems to be incorporated in current versions of GSM --
  http://webapp.etsi.org/action/OP/OP20000929/en_301349v080400o.pdf
-- is there really any need to add explicit link condition adaptation 
at the TCP or ICMP protocol levels?  I don't want to be in a position 
of advocating the change or addition of anything to those protocols 
unless absolutely necessary.

As far as robust wireless TCP goes, you are absolutely right that good 
service requires a maximum RTO shorter than the standard 64 seconds.  
What is that value in your TCP-Eiffel?

And one parameter that the DoCoMo draft doesn't mention (perhaps it 
goes without saying to most people) is a total retransmit timeout much 
longer than the typical 2-9 minutes.  Again, what do you use; an hour?

Cheers,
James

P.S. Please keep at least ietf-mmms@imc.org in on this, as the lack 
of ubiquitous wireless TCP is related to Mobile Multimedia Messaging 
applications.
Received on Monday, 18 September 2000 23:10:00 GMT

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