6 Feb
2019
6 Feb
'19
5:49 p.m.
On Wed, Feb 06, 2019 at 10:16:24AM -0700, Warner Losh
wrote:
In many ways, it was a classic second system effect
because they were
trying to fix everything they thought was wrong with TCP/IP at the time
I'm not sure this part is accurate: the two efforts were contemporaneous; and
my impression was they were trying to design the next step in networking, based
on _their own_ analysis of what was needed.
without really, truly knowing the differences between
actual problems
and mere annoyances and how to properly weight the severity of the issue
in coming up with their solutions.
This is I think true, but then again, TCP/IP fell into some of those holes
too: fragmentation for one (although the issue there was unforseen problems in
doing it, not so much in it not being a real issue), all the 'unused' fields
in the IP and TCP headers for things that never got really got
used/implemented (Type of Service, Urgent, etc).
` Noel
6 Feb
6 Feb
6:22 p.m.
New subject: OSI stack (Was: Posters)
On 2/6/19, Noel Chiappa <jnc(a)mercury.lcs.mit.edu> wrote:
That's my recollection as well. The OSI effort was dominated by the
European telcos, nearly all of which were government-run monopolies.
They were as much (if not more) interested in protecting their own
turf as in developing the next step in networking. A lot of the
complexity came from the desire to be everything to everybody. As is
often the case, the result was being nothing to nobody.
Phase V of DEC's networking product (DECnet) supported X.25 as an
alternative to DEC's proprietary transport/routing layer. I had to
install this on one of our VAXen so we could test DECmail, our
forthcoming X.400 product. I remember X.25 being excessively
complicated and a bear to set up compared to Phase IV DECnet (the
proprietary protocol stack).
-Paul W.
On Wed, Feb
06, 2019 at 10:16:24AM -0700, Warner Losh wrote:
In many ways, it was a classic second system
effect because they were
trying to fix everything they thought was wrong with TCP/IP at the time
I'm not sure this part is accurate: the two efforts were contemporaneous; and
my impression was they were trying to design the next step in networking, based
on _their own_ analysis of what was needed. 
8:47 p.m.
New subject: OSI stack (Was: Posters)
At risk of inciting some inflammation I think TCP was a success because of
BSD/UNIX rather than its own merits. Moving the stack into the kernel,
therefore not requiring elaborate external communications controllers (like
IBM's VTAM, predecessors, and other vendor networking approaches that
existed since the '60s), and piggybacking on the success of UNIX and then
"open systems" cemented victory. It has basically been made to work at
scale, the same way gasoline engines have been made to work in automobiles.
There were protocols that fit better in the era like DeltaT with a simpler
state machine and connection handling. Then there was a mad dash of
protocol development in the mid to late ‘80s that were measured by various
metrics to outperform TCP in practical and theoretical space. Some of
these seemed quite nice like XTP and are still in use in niche defense
applications.
Positive, rather than negative acknowledgement has aged well as computers
got more powerful (the sender can pretty well predict loss when it hasn't
gotten an ACK back and opportunistically retransmit). But RF people do
weird things that violate end to end principle on cable modems and radios
to try and minimize transmissions.
One thing I think that is missing in my contemporary modern software
developers is a willingness to dig down and solve problems at the right
level. People do clownish things like write overlay filesystems in garbage
collected languages. Google's QUIC is a fine example of foolishness. I am
mortified that is genuinely being considered for the HTTP 3 standard. But
I guess we've entered the era where enough people have retired that the
lower layers are approached with mysticism and deemed unable and unsuitable
to change. So the layering will continue until eventually things topple
over like the garbage pile in the movie Idiocracy.
Since the discussion meandered to the distinction of path
selection/routing.. for provider level networks, label switching to this
day makes a lot more sense IMO.. figure out a path virtual circuit that can
cut through each hop with a small flow table instead of trying to
coagulate, propagate routes from a massive address space that has to fit in
an expensive CAM and buffer and forward packets at each hop.
Regards,
Kevin
On Wed, Feb 6, 2019 at 10:49 AM Noel Chiappa <jnc(a)mercury.lcs.mit.edu>
wrote:
On Wed, Feb
06, 2019 at 10:16:24AM -0700, Warner Losh wrote:
In many ways, it was a classic second system
effect because they were
trying to fix everything they thought was wrong with TCP/IP at the
time
I'm not sure this part is accurate: the two efforts were contemporaneous;
and
my impression was they were trying to design the next step in networking,
based
on _their own_ analysis of what was needed.
without really, truly knowing the differences
between actual problems
and mere annoyances and how to properly weight the severity of the
issue
in coming up with their solutions.
This is I think true, but then again, TCP/IP fell into some of those holes
too: fragmentation for one (although the issue there was unforseen
problems in
doing it, not so much in it not being a real issue), all the 'unused'
fields
in the IP and TCP headers for things that never got really got
used/implemented (Type of Service, Urgent, etc).
` Noel
7 Feb
7 Feb
6:07 p.m.
New subject: OSI stack (Was: Posters)
Seeing as how this is diverging from TUHS, I'd encourage replies to the
COFF copy that I'm CCing.
On 02/06/2019 01:47 PM, Kevin Bowling wrote:
There were protocols that fit better in the era like
DeltaT with a
simpler state machine and connection handling. Then there was a mad
dash of protocol development in the mid to late ‘80s that were measured
by various metrics to outperform TCP in practical and theoretical
space. Some of these seemed quite nice like XTP and are still in use in
niche defense applications.
$ReadingList++
Positive, rather than negative acknowledgement has
aged well as
computers got more powerful (the sender can pretty well predict loss
when it hasn't gotten an ACK back and opportunistically retransmit).
But RF people do weird things that violate end to end principle on cable
modems and radios to try and minimize transmissions.
Would you care to elaborate?
One thing I think that is missing in my contemporary
modern software
developers is a willingness to dig down and solve problems at the right
level. People do clownish things like write overlay filesystems in
garbage collected languages. Google's QUIC is a fine example of
foolishness. I am mortified that is genuinely being considered for the
HTTP 3 standard. But I guess we've entered the era where enough people
have retired that the lower layers are approached with mysticism and
deemed unable and unsuitable to change. So the layering will continue
until eventually things topple over like the garbage pile in the movie
Idiocracy.
I thought one of the reasons that QUIC was UDP based instead of it's own
transport protocol was because history has shown that the possibility
and openness of networking is not sufficient to encourage the adoption
of newer technologies. Specifically the long tail of history / legacy
has hindered the introduction of a new transport protocol. I thought I
remembered hearing that Google wanted to do a new transport protocol,
but they thought that too many things would block it thus slowing down
it's deployment. Conversely putting QUIC on top of UDP was a minor
compromise that allowed the benefits to be adopted sooner.
Perhaps I'm misremembering. I did a quick 45 second search and couldn't
find any supporting evidence.
The only thing that comes to mind is IPsec's ESP(50) and AH(51) which—as
I understand it—are filtered too frequently because they aren't ICMP(1),
TCP(6), or UDP(17). Too many firewalls interfere to the point that they
are unreliable.
Since the discussion meandered to the distinction of
path
selection/routing.. for provider level networks, label switching to this
day makes a lot more sense IMO.. figure out a path virtual circuit that
can cut through each hop with a small flow table instead of trying to
coagulate, propagate routes from a massive address space that has to fit
in an expensive CAM and buffer and forward packets at each hop.
I think label switching has it's advantages. I think it also has some
complications.
I feel like ATM, Frame Relay, and MPLS are all forms of label switching.
Conceptually they all operate based on a per-programed path.
--
Grant. . . .
unix || die
6:22 p.m.
New subject: OSI stack (Was: Posters)
On Thursday, February 7, 2019, Grant Taylor via TUHS <tuhs(a)minnie.tuhs.org>
wrote:
Seeing as how this is diverging from TUHS, I'd
encourage replies to the
COFF copy that I'm CCing.
On 02/06/2019 01:47 PM, Kevin Bowling wrote:
XTP was/is indeed very interesting. It was adopted by US Navy for SAFENET
and created by Greg Chesson who was active in the early UNIX community.
Not sure if we have him here on this list though.
--Andy
There were protocols that fit better in the era
like DeltaT with a
simpler state machine and connection handling. Then there was a mad dash
of protocol development in the mid to late ‘80s that were measured by
various metrics to outperform TCP in practical and theoretical space. Some
of these seemed quite nice like XTP and are still in use in niche defense
applications.
$ReadingList++ 
6:33 p.m.
New subject: [COFF] OSI stack (Was: Posters)
On Thu, Feb 7, 2019 at 1:22 PM Andy Kosela <akosela(a)andykosela.com> wrote:
On Thursday, February 7, 2019, Grant Taylor via TUHS
<tuhs(a)minnie.tuhs.org>
wrote:
Sadly, Greg Chesson passed away a couple of years ago after battling cancer
for some time.
- Dan C.
Seeing as how this is diverging from TUHS,
I'd encourage replies to the
COFF copy that I'm CCing.
On 02/06/2019 01:47 PM, Kevin Bowling wrote:
XTP was/is indeed very interesting. It was adopted by US Navy for SAFENET
and created by Greg Chesson who was active in the early UNIX community.
Not sure if we have him here on this list though.
There were protocols that fit better in the era
like DeltaT with a
simpler state machine and connection handling. Then there was a mad dash
of protocol development in the mid to late ‘80s that were measured by
various metrics to outperform TCP in practical and theoretical space. Some
of these seemed quite nice like XTP and are still in use in niche defense
applications.
$ReadingList++ 
6:50 p.m.
New subject: OSI stack (Was: Posters)
On Thu, Feb 07, 2019 at 11:07:27AM -0700, Grant Taylor via TUHS wrote:
On 02/06/2019 01:47 PM, Kevin Bowling wrote:
Greg Chesson was the guy behind XTP. I worked for him at SGI, he was a
hoot (lost him to cancer a while back). I think I've posted this before
but here he is not long before he died (he came up to bitch about kids
these days with their shiney frameworks and new fangled languages, what's
wrong with C?)
http://mcvoy.com/lm/xtp+excavator
He was an engineer to the core, he refused to take any info from me on how
to run the machine, just sat there and figured it out.
--lm
There were protocols that fit better in the era
like DeltaT with a simpler
state machine and connection handling.?? Then there was a mad dash of
protocol development in the mid to late ???80s that were measured by
various metrics to outperform TCP in practical and theoretical space.??
Some of these seemed quite nice like XTP and are still in use in niche
defense applications.
$ReadingList++
1904
days inactive
1905
days old
6 comments
7 participants
participants (7)
-
Andy Kosela -
Dan Cross -
Grant Taylor -
jnc＠mercury.lcs.mit.edu -
Kevin Bowling -
Larry McVoy -
Paul Winalski