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Groups > comp.arch.embedded > #25592

Re: UDP Terminal Protocol

From Don Y <blockedofcourse@foo.invalid>
Newsgroups comp.arch.embedded
Subject Re: UDP Terminal Protocol
Date 2016-12-15 22:00 -0700
Organization A noiseless patient Spider
Message-ID <o2vsb8$b2f$1@dont-email.me> (permalink)
References <7phv4cd0dickoubm7k7rud6or7vtnft8rb@4ax.com> <o2p3bs$7fc$1@reader1.panix.com> <qs535ctbk361kav29rjd236dat22mo199e@4ax.com> <o2sh2a$u08$1@dont-email.me> <o2vob7$1ps$2@dont-email.me>

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On 12/15/2016 8:52 PM, Les Cargill wrote:
> Don Y wrote:
>> On 12/14/2016 12:28 PM, Robert Wessel wrote:
> <snip>
>> TFTP without the "windowsize" option handles the problem just by requesting
>> retransmits until you've "got" the next packet IN SEQUENCE.  Support
>> for the windowsize forces the client to keep track of *which* packets
>> it's received -- and tolerate the possibility that it might accumulate
>> them out-of-order in how it frames its acknowledgements.
>
> I am pretty sure bootp only works on local segments. Not 100% sure about TFTP,
> but I would be surprised if it survived fragmentation or
> changes in sequencing.

Classic TFTP only allows one outstanding packet.  Later revisions
allow a window size to be negotiated -- essentially allowing
multiple packets to be on the wire (from the standpoint of the
client) simultaneously.  Client-side code decides which packets
to acknowledge and when.  So, if a packet 5 (of 1-8 in this window)
arrives later than the client "planned", 1-4 are acknowledged
causing 5-12 to be sent in the next window... even if the "first" 5
arrives just after the ack has been sent.

You can workaround fragmentation by negotiating a suitable packet
size (yet another extension to the original TFT protocol).

I.e., you can conceivably configure TFTP to bridge routers
*if* that's a deliberate goal.

BOOTP only addresses the idea of centralizing the devices'
configurations (instead of having to push them into the
device at "install time").  DHCP can achieve similar results
(in a more modern approach).

[Of course, you can also bastardize any number of protocols
to come up with your own approach -- "downloading" configuration
"files" that are named (by convention) with the MAC address
of the device in question, etc.  But, you want to be cognizant of
typical "best practices" so you don't pose a system configuration
headache for the network administrator(s)]

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Thread

UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-13 04:23 -0600
  Re: UDP Terminal Protocol Dimiter_Popoff <dp@tgi-sci.com> - 2016-12-13 17:10 +0200
    Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-14 13:33 -0600
  Re: UDP Terminal Protocol Grant Edwards <invalid@invalid.invalid> - 2016-12-13 15:16 +0000
    Re: UDP Terminal Protocol upsidedown@downunder.com - 2016-12-13 18:51 +0200
      Re: UDP Terminal Protocol Grant Edwards <invalid@invalid.invalid> - 2016-12-13 21:13 +0000
        Re: UDP Terminal Protocol Clifford Heath <no.spam@please.net> - 2016-12-14 09:05 +1100
      Re: UDP Terminal Protocol Rob Gaddi <rgaddi@highlandtechnology.invalid> - 2016-12-13 13:23 -0800
    Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-14 13:28 -0600
      Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-14 15:29 -0700
        Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-15 00:34 -0600
          Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-15 01:10 -0700
        Re: UDP Terminal Protocol Les Cargill <lcargill99@comcast.com> - 2016-12-15 21:52 -0600
          Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-15 22:00 -0700
      Re: UDP Terminal Protocol Paul Rubin <no.email@nospam.invalid> - 2016-12-14 15:22 -0800
        Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-15 00:00 -0600
      Re: UDP Terminal Protocol antispam@math.uni.wroc.pl - 2016-12-15 01:49 +0000
        Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-15 00:17 -0600
      Re: UDP Terminal Protocol Grant Edwards <invalid@invalid.invalid> - 2016-12-15 02:06 +0000
        Re: UDP Terminal Protocol Paul Rubin <no.email@nospam.invalid> - 2016-12-14 21:09 -0800
          Re: UDP Terminal Protocol Grant Edwards <invalid@invalid.invalid> - 2016-12-15 17:38 +0000
        Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-14 23:58 -0600
      Re: UDP Terminal Protocol Les Cargill <lcargill99@comcast.com> - 2016-12-15 21:49 -0600
      Re: UDP Terminal Protocol Morten Reistad <first@last.name.invalid> - 2016-12-24 16:10 +0100
        Re: UDP Terminal Protocol Grant Edwards <invalid@invalid.invalid> - 2016-12-24 18:53 +0000
          Re: UDP Terminal Protocol Theo Markettos <theom+news@chiark.greenend.org.uk> - 2016-12-25 13:45 +0000
            Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-25 11:44 -0700
  Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-13 12:53 -0700
    Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-14 14:03 -0600
      Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-14 15:09 -0700
        Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-15 00:50 -0600
          Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-15 11:01 -0700
        Re: UDP Terminal Protocol Morten Reistad <first@last.name.invalid> - 2017-01-15 16:08 +0100
      Re: UDP Terminal Protocol upsidedown@downunder.com - 2016-12-15 15:08 +0200
  Re: UDP Terminal Protocol wzab01@gmail.com - 2016-12-14 13:16 -0800
  Re: UDP Terminal Protocol upsidedown@downunder.com - 2016-12-15 12:56 +0200
    Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-15 11:06 -0700
      Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-26 16:34 -0600
        Re: UDP Terminal Protocol upsidedown@downunder.com - 2016-12-27 07:45 +0200
        Re: UDP Terminal Protocol Don Y <blockedofcourse@foo.invalid> - 2016-12-26 23:00 -0700
          Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2017-01-03 18:48 -0600
  Re: UDP Terminal Protocol Les Cargill <lcargill99@comcast.com> - 2016-12-15 21:42 -0600
    Re: UDP Terminal Protocol Robert Wessel <robertwessel2@yahoo.com> - 2016-12-26 17:21 -0600

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