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From: randy@oresoft.UUCP (Randy Bush)
Newsgroups: rec.ham-radio.packet,comp.dcom.modems
Subject: Re: Gilmore responds...
Message-ID: <65@oresoft.UUCP>
Date: Mon, 7-Sep-87 12:29:05 EDT
Article-I.D.: oresoft.65
Posted: Mon Sep  7 12:29:05 1987
Date-Received: Tue, 8-Sep-87 06:07:53 EDT
References: <115@splut.UUCP> <7176@steinmetz.steinmetz.UUCP> <581@omen.UUCP>
Reply-To: randy@oresoft.UUCP (Randy Bush)
Distribution: na
Organization: Oregon Software, Portland OR
Lines: 19
Summary: SEAlink has an 'ACKless' version
Xref: mnetor rec.ham-radio.packet:510 comp.dcom.modems:932

caf@omen.UUCP (Chuck Forsberg WA7KGX) writes:
>SEAlink uses 128 byte XMODEM style packets with no protection
>for flow control or network command characters.  A SEAlink receiver
>generates an ACK every 128 bytes, impacting throughput on buffered
>modems etc.

Indeed, SEAlink has no protection for network command sequences or flow
control.  Although this does give an efficiency gain, one must set up a
network connection (e.g. PCP) using a script which negotiates with the PAD.

A SEAlink receiver does not necessarily generate an ACK every 128-byte packet.
On high speed connections, the version in SEAdog 4.1 goes into 'overdrive',
which is ACKless.  This greatly improves performance using semi half-duplex
modems such as the Telebit Trailblazer.

This is not to say that SEAlink is a robust protocol.
-- 
Randy Bush, Compiler Group, Oregon Software, Portland Oregon (503) 245-2202
uucp: ..!tektronix!oresoft!randy       Telemail: RBush     Fidonet: 1:105/6