[ih] X.25 networking (was: Re: sad news: Peter Kirstein)
Toerless Eckert
tte at cs.fau.de
Sun Jan 12 00:03:10 PST 2020
Any more specific definition for "protocol conversion ?" other than
"anything thats not just overlay" ?
I am asking, because conceptually, i see little difference between
running IP at a UNI (Host<->Network) and NNI (SP<->), or running
X.25 at UNI and X.75 at NNI. Would you describe an IP SP<->SP connection
with IP as "protocol conversion" ?
Also:
https://en.wikipedia.org/wiki/International_Packet_Switched_Service
Looks to me as if Peter's side in the UK would rather have been a
user (DTE) of IPSS, tunneling IP all the way to the USA across an X.25
connection. In that case, UCL would have just had an X.25 interface to
IPSS. X.75 would have been used likely on the interconnects between the
three operators of IPSS.
Would be interesting to know what was charged for IPSS internationally
back then.
I only did international X.25 from my university in Germany to the
US west coast in the mid 80th for something better predictable in
volume than IP, namely UUCP for email. Even running IP to another university
in Germany set us back up to 7000 EUR/month to Deutsche Telekom (in
todays money) and was of course not funded ("what is IP and why do you need
it").
Cheers
Toerless
On Sat, Jan 11, 2020 at 02:15:26PM -0500, John Day via Internet-history wrote:
> As Abbate relates in her book, there were two approaches to ???internetworking??? protocol conversion at the boundaries and doing an overlay. The CCITT (ITU) chose protocol conversion with X.75, researchers and computer vendors chose the overlay approach.
>
> Take care,
> John
>
> > On Jan 11, 2020, at 01:27, the keyboard of geoff goodfellow via Internet-history <internet-history at elists.isoc.org> wrote:
> >
> > seem to recall that the different x.25 networks (in different countries)
> > connected via x.75 gateways?
> >
> > and weren't these x.25/x.75 "peering" network interconnections treated much
> > like their telco mother ships voice networks in that (unlike the Internet
> > where sender keeps all) there were settlements involved?
> >
> > furthermore, kinda recall that not only did these x.25 circuit switched
> > networks clock you with a fee for the time of the virtual circuit as Jack
> > mentioned, but they also summarily docked you for the bits sent as well?
> >
> > seem to also recall that the x.25 networks were painfully slow and didn't
> > allow (more than 1?) multiple packets outstanding?
> >
> > and also kinda recall that the CSnet x.25 implementation employed an
> > automobiles alternator type of thingy in that it opened something like 5(?)
> > virtual circuits simultaneously and then sequentially round robin'd the
> > data, er, packets through these vc's to effectuate higher throughputage?
> >
> >
> > On Fri, Jan 10, 2020 at 7:53 PM Vint Cerf via Internet-history <
> > internet-history at elists.isoc.org> wrote:
> >
> >> I had thought that there was some kind of reciprocal agreement that the USG
> >> would charge the X.25 carrier the same amount that the X.25 carrier charged
> >> - a kind of net zero peering arrangement. Let me do a little research.
> >> v
> >>
> >>
> >> On Fri, Jan 10, 2020 at 8:43 PM Brian E Carpenter <
> >> brian.e.carpenter at gmail.com> wrote:
> >>
> >>> Jack,
> >>>
> >>>> I've wondered for
> >>>> years how much of ARPA's expenses we moved into Peter's UCL budget.
> >> And
> >>>> whether Peter or anyone else realized what was happening.
> >>>
> >>> It wouldn't surprise me in the least if Peter knew and decided to keep
> >>> quiet. This was presumably around 1980? The transatlantic "who pays?"
> >>> discussions got very explicit when NSFnet entered the picture a few years
> >>> later.
> >>>
> >>> UCL was monitoring usage as early as 1975:
> >>> Monitoring and access control of the London node of ARPANET
> >>> https://dl.acm.org/doi/10.1145/1499799.1499882
> >>> As for many years afterwards, the bulk of traffic was from the US towards
> >>> Europe, and most of the sessions were started by European users. (I
> >>> happened to notice this paper since one of Peter's co-authors was later
> >> in
> >>> my team at CERN.)
> >>>
> >>> For proof that Peter was aware of the X.25 cost issue before too long,
> >> see
> >>> the bottom of page 10 at
> >> http://nrg.cs.ucl.ac.uk/mjh/kirstein-arpanet.pdf
> >>> "The access control was because we were
> >>> incurring IPSS traffic charges on out-going traffic; the logging was
> >>> because the
> >>> funding agencies wanted to know how to allocate costs."
> >>>
> >>> Regards
> >>> Brian Carpenter
> >>>
> >>> On 11-Jan-20 12:48, Jack Haverty via Internet-history wrote:
> >>>> Thanks Vint, I hope it gives them some insight into Peter's work life.
> >>>>
> >>>> I remembered another anecdote that might also be interesting...
> >>>>
> >>>> Peter was the primary contact I knew on the EU side of the US/EU
> >>>> partnership. I never knew the details, but I suspect there was lots of
> >>>> diplomacy, negotiations and agreements involved involving the several
> >>>> governments. Some of them of course involved money - who would pay
> >> for
> >>>> this new experimental Internet thing.
> >>>>
> >>>> Some time after the initial gateway linkage made the Internet cross the
> >>>> Atlantic, we put a second pathway into place, by using the public X.25
> >>>> network as just another network subsumed by the Internet.
> >>>>
> >>>> This was called the "VAN Gateway". After it was put into operation,
> >>>> Internet traffic between the EU and US could traverse the satellite
> >>>> network, that ARPA paid for, or it could traverse the international
> >> X.25
> >>>> network.
> >>>>
> >>>> The X.25 network consumed money differently than the ARPA-funded parts
> >>>> of the Internet. In particular, the monthly cost of using the X.25
> >>>> pathway was unpredictable. Since the X.25 world evolved from
> >>>> traditional telephone companies, it had retained the notion of "calls",
> >>>> and charged based on how long each call was connected. So a simple
> >>>> 5-minute call would be inexpensive, while a large file transfer that
> >>>> might take a day or more to complete would be quite expensive. It all
> >>>> depended on what those pesky Users (like Peter and his crew) did as
> >> they
> >>>> used the Internet.
> >>>>
> >>>> The ARPA beancounters weren't too comfortable with unpredictable and
> >>>> uncontrollable monthly expenses. So we (BBN) brainstormed about what
> >>>> we might do to mitigate that risk.
> >>>>
> >>>> So....... The gateways couldn't really predict what future traffic
> >>>> might appear. It depended on what those pesky Users did. The
> >>>> algorithm we implemented did its best to be somewhat efficient in using
> >>>> that expensive X.25 service. When a datagram arrived that was to be
> >>>> sent over the X.25 path, the gateway would see if the "call" between
> >> the
> >>>> two gateways was still active from previous traffic. If not, it would
> >>>> "dial up" the other end and then send the datagram on its way, and also
> >>>> start, or reset, a timer. After a while when the timer expired due to
> >>>> inactivity the gateway would simply "hang up", to prevent the
> >> per-minute
> >>>> charges from piling up.
> >>>>
> >>>> That would help, but if someone did a huge file transfer it could still
> >>>> run up a lot of charges for ARPA. More brainstorming....
> >>>>
> >>>> So, ...... We simply configured the timer on the US side to be very
> >>>> short - just long enough to get one datagram across the Atlantic.
> >>>> probably about 1 second. We set the corresponding timer on the EU side
> >>>> somewhat longer - a minute or so, so it would hang up quickly when the
> >>>> user traffic subsided.
> >>>>
> >>>> The X.25 mechanisms behaved like the traditional telephone system, the
> >>>> bill for each "call" would go to whichever party "dialed the phone".
> >>>> With the timers set so differently, almost all of the calls of any
> >>>> duration would be initiated by the gateway on the EU side of the
> >>>> Atlantic, regardless of where the associated TCP connection was
> >> created.
> >>>>
> >>>> So, ....The result was that most of the expense of using the X.25
> >>>> pathway, and almost all of the unpredictability, fell onto the EU side
> >>>> of the partnership.
> >>>>
> >>>> Somewhere in my education, I learned that "Management is the Art of
> >>>> Moving Your Expenses Into Someone Else's Budget." I've wondered for
> >>>> years how much of ARPA's expenses we moved into Peter's UCL budget.
> >> And
> >>>> whether Peter or anyone else realized what was happening.
> >>>>
> >>>> /Jack Haverty
> >>>>
> >>>>
> >>>> On 1/9/20 8:06 PM, Vint Cerf wrote:
> >>>>> thanks for this reminiscence - I am sharing with Peter's family whom
> >>>>> we will see on Saturday.
> >>>>>
> >>>>> vint
> >>>>>
> >>>>>
> >>>>> On Thu, Jan 9, 2020 at 5:11 PM Jack Haverty via Internet-history
> >>>>> <internet-history at elists.isoc.org
> >>>>> <mailto:internet-history at elists.isoc.org>> wrote:
> >>>>>
> >>>>> Peter was, IMHO, possibly the most important driving force behind
> >>>>> getting the fledgling Internet to actually work! Peter (and his
> >>>>> group)
> >>>>> was the only "real" User of the Internet back in 1981. Or at
> >>>>> least the
> >>>>> most memorable to me.
> >>>>>
> >>>>> Summer/Fall 1981 was when Vint added an "Internet" task to my
> >>> group's
> >>>>> contract at BBN, with the assignment to make the Internet work
> >>>>> reliably
> >>>>> as a 24x7 communications service, just like we had been doing for
> >>> the
> >>>>> ARPANET for a decade. The Internet then was just a handful or so
> >> of
> >>>>> "gateways" (now called "routers") interconnecting networks.
> >>>>>
> >>>>> Most "Internet traffic" then actually moved across the ARPANET,
> >>> which
> >>>>> was not only reliable but also rarely did nasty things like
> >>>>> dropping IP
> >>>>> datagrams, reordering them, and otherwise mangling datagram
> >>>>> flows. The
> >>>>> neonatal TCP implementations, running over the ARPANET, didn't
> >>>>> have much
> >>>>> real work to do in moving users' data. The ARPANET did most of
> >> the
> >>>>> heavy lifting for them.
> >>>>>
> >>>>> However, Peter and the UCL group were actually trying to use an
> >>>>> Internet
> >>>>> path which involved at least 2 resource-starved gateways and
> >> several
> >>>>> networks of different speeds, delays, etc. Unlike most users,
> >> the
> >>>>> Internet was supporting Peter's group's everyday activities, not
> >>> just
> >>>>> occasional network experiments. And they really used it. And
> >> they
> >>>>> exposed lots of problems.
> >>>>>
> >>>>> Being on the EU side of the Atlantic, they always had a 5 hour or
> >> so
> >>>>> headstart on us every day. So there were often problems, waiting
> >>> for
> >>>>> BBN to "fix the Internet" every morning - especially after it
> >> became
> >>>>> known that BBN was tasked to make the Internet work as a 24x7
> >>> reliable
> >>>>> service.
> >>>>>
> >>>>> IMHO, that pressure from real users with real problems was a key
> >>>>> driver
> >>>>> to all the things we had to do to get the Internet out of the
> >>>>> "research
> >>>>> lab" to come online as a reliable communications service.
> >>>>>
> >>>>> Peter made (us make) the Internet work...
> >>>>>
> >>>>> /Jack Haverty
> >>>>>
> >>>>>
> >>>>>
> >>>>> On 1/8/20 8:09 PM, Vint Cerf via Internet-history wrote:
> >>>>>> Looking at this from a different perspective, we had Peter in
> >>>>> our midst and
> >>>>>> contributing heavily to networking successes and spread from
> >>>>> about 1967
> >>>>>> when I first met him while at UCLA. That's over half a century.
> >>>>> What a
> >>>>>> gift! His work is still evident and his story of collaboration
> >>>>> undiminished
> >>>>>> by his departure from our midst. Yes, another giant has left us,
> >>>>> but his
> >>>>>> work remains to remind us of what we can do when we work
> >>>>> together. None of
> >>>>>> that is gone though we shall not see him again in this world.
> >>>>>>
> >>>>>> I am glad to have called him "friend" for many, many years.
> >>>>>> vint
> >>>>>>
> >>>>>>
> >>>>>> On Wed, Jan 8, 2020 at 9:27 PM Bob Hinden via Internet-history <
> >>>>>> internet-history at elists.isoc.org
> >>>>> <mailto:internet-history at elists.isoc.org>> wrote:
> >>>>>>
> >>>>>>>
> >>>>>>>> On Jan 8, 2020, at 11:38 AM, Toerless Eckert via
> >>>>> Internet-history <
> >>>>>>> internet-history at elists.isoc.org
> >>>>> <mailto:internet-history at elists.isoc.org>> wrote:
> >>>>>>>> On Thu, Jan 09, 2020 at 08:26:00AM +1300, Brian E Carpenter
> >> via
> >>>>>>> Internet-history wrote:
> >>>>>>>>> This is really bad news. And don't forget his team's true
> >>>>> pioneering in
> >>>>>>> video-conferencing over the Internet too.
> >>>>>>>> Indeed
> >>>>>>> Yes, very sad news indeed. Sigh...
> >>>>>>>
> >>>>>>> Bob
> >>>>>>>
> >>>>>>>> All MICE and friends will miss him dearly, and keep fond
> >>> memories.
> >>>>>>>>
> >>>>>>>> Toerless
> >>>>>>>>
> >>>>>>>>> Regards
> >>>>>>>>> Brian Carpenter
> >>>>>>>>>
> >>>>>>>>> On 09-Jan-20 06:17, Vint Cerf via Internet-history wrote:
> >>>>>>>>>> I am sorry to relay the sad news that Peter Kirstein passed
> >>>>> away this
> >>>>>>>>>> morning (London time). He was a key implementer and promoter
> >>> of
> >>>>>>> networking,
> >>>>>>>>>> participating in both the ARPANET and Internet developments
> >>>>> as well as
> >>>>>>> the
> >>>>>>>>>> UK Coloured Book and Open Systems Interconnection protocols.
> >>>>>>>>>> https://en.wikipedia.org/wiki/Peter_T._Kirstein
> >>>>>>>>>>
> >>>>>>>>>> vint cerf
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