From owner-freebsd-current  Sun Oct 11 21:02:22 1998
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Received: (from majordom@localhost)
          by hub.freebsd.org (8.8.8/8.8.8) id VAA29475
          for freebsd-current-outgoing; Sun, 11 Oct 1998 21:02:22 -0700 (PDT)
          (envelope-from owner-freebsd-current@FreeBSD.ORG)
Received: from widefw.csl.sony.co.jp (widefw.csl.sony.co.jp [133.138.1.1])
          by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id VAA29470
          for <current@FreeBSD.ORG>; Sun, 11 Oct 1998 21:02:19 -0700 (PDT)
          (envelope-from kjc@csl.sony.co.jp)
Received: from hotaka.csl.sony.co.jp (root@hotaka.csl.sony.co.jp [43.27.98.57])
	by widefw.csl.sony.co.jp (8.8.8/3.6W) with ESMTP id MAA26432;
	Mon, 12 Oct 1998 12:38:45 +0900 (JST)
Received: from localhost (kjc@[127.0.0.1])
	by hotaka.csl.sony.co.jp (8.8.8/3.6W/hotaka/98021914) with ESMTP id MAA07249;
	Mon, 12 Oct 1998 12:38:44 +0900 (JST)
Message-Id: <199810120338.MAA07249@hotaka.csl.sony.co.jp>
To: Brian Somers <brian@Awfulhak.org>
cc: current@FreeBSD.ORG
Subject: Re: Improper sharing of modem bandwidth 
In-reply-to: Your message of "Fri, 09 Oct 1998 10:58:48 +0100."
             <199810090958.KAA00774@woof.lan.awfulhak.org> 
Date: Mon, 12 Oct 1998 12:38:44 +0900
From: Kenjiro Cho <kjc@csl.sony.co.jp>
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG


Brian,

How hard do you think it is to add the following feature to the
userland ppp?

The issll working group at IETF 
(http://www.ietf.org/html.charters/issll-charter.html)
proposes a suspend/resume style transmission method:
"PPP in a real-time oriented HDLC-like framing".
(http://www.ietf.org/internet-drafts/draft-ietf-issll-isslow-rtf-03.txt)

The basic idea is that, if a FIFO based serial chip is used, we are
able to control the transmission of each byte so that we can suspend a
low-priority packet in the middle of the transmission.
In the above draft, the frame format and the negotiation format is
defined as an extension to the PPP Multilink fragmentation protocol.

With the packet-by-packet control, the latency is more than 500 ms
over 64Kbps with 1500-byte MTU.
I believe that the latency of telnet will be less than 50 ms even in
the middle of ftp, if the suspend/resume is implemented.

--Kenjiro

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message