[ih] The First Atlantic CyberWar - was uucp

[Jack Haverty]

Since there's a lot of UUCP memories still intact, I was just curious 
about a possible relationship between UUCP and some battles in the First 
Atlantic CyberWar (FACW).

Basically, my question is whether or not the UUCP implementers used 
similar tactics to manage their site's budget and expenses for dialup 
calls.   Or were we the first?

What, you never heard of the FACW!?  Few people did; even the combatants 
might not have known.

Circa 1982 or so, we added the "VAN Gateway" to the Internet.  At the 
time, the transatlantic interconnection was provided by SATNET, which 
was restricted to use by projects of interest to ARPA.  They were paying 
the bills and satellite channels were expensive.

More people and projects in EU wanted to "get on the 'net" and 
collaborate with US counterparts.  But ARPA was reluctant to add more 
usage to the SATNET.  The VAN gateway was added to provide an alternate 
"second path" connecting the US to EU (specifically at UCL in London and 
from there probably to other countries).

The public X.25/X.75 network already existed and could provide 
connections "across the pond".  Rather expensive too, IIRC.  The "VAN 
Gateway" was created by simply adding to a gateway a driver for another 
kind of circuit - namely the virtual circuit provided by X.25.

This of course caused all sorts of confusion to all the people who were 
enamored of the 7-layer model of ISO.   The entire public ISO X.25/X.75 
international network was treated as a link layer circuit in the ARPA 
Internet.  I gave up long ago on trying to stuff this into a 7-layer 
diagram and explain it.

I wasn't involved in the deal, but I think it involved adding a gateway 
at BBN that knew how to use the X.25 public network, as well as 
modifying another gateway at UCL, built by UCL, to have similar 
capabilities.  ARPA would pay for the US side, and UCL (or perhaps 
UKMOD?) would pay for the EU side.  The bulk of the ongoing costs were 
expected to be the charges from the public net connections. More use 
would mean more expense.

That configuration led to a discussion of "policy-based routing", in 
which traffic would flow over different paths depending on what policy 
dictated - e.g.,  traffic for some projects would go one way, while 
traffic for other projects went another.   Even from the same host computer.

We didn't know how to do that, so "policy routing" went on the 
longer-term to-do list.  Meanwhile, a routing hack was implemented by 
assigning computers two IP addresses, even if they were connected to the 
same LAN.  A single Ethernet might have two different network numbers, 
and its computers have two very different IP addresses, with traffic 
taking different paths depending on the address the computer software 
decided to use as its Source Address.

That addressed the problem of unauthorized use of SATNET.  Still, there 
was concern about the X.25 costs.  Just like dialup phone calls, X.25 
calls were billed based on connection time.   So there was a need for 
the gateways to shut down a connection if it had been idle for a while.  
But there was no way in the IP protocol for a host to signal "I'm done" 
to the gateways to initiate a "hangup" of the X.25 connection.

X.25 connections were billed by something like a charge "per minute or 
fraction thereof".  So if there had been no traffic for a minute or so, 
it would make sense to shut down the X.25 connection.  Both sides of the 
Atlantic implemented that.  The next IP datagram crossing the Atlantic 
would reopen the connection so the disconnect would be invisible to the 
hosts and users.  TCP wouldn't care.

Still, we were concerned about the unpredictable and unbounded nature of 
the X.25 charges.  So we fired the first round in the FACW.

The US gateway was configured so that, instead of waiting for a minute 
of no traffic flow, it would shut down the connection immediately but 
only after it had to open a connection to send an IP datagram toward 
EU.   The recipient TCP would likely respond to continue the TCP 
connection.  When that response datagram got to the EU gateway, it would 
open the connection to the US.  Subsequent traffic would that connection 
until eventually the connection became idle for a minute and was closed.

Result - the bulk of the charges for the international X.25 calls were 
billed to the EU side.  That followed the old management doctrine "The 
best way to control your expenses is to move them into someone else's 
budget."  We never saw the bills themselves so it's difficult to say how 
effective that was.  No one complained though. Probably no one noticed.

AFAIK, there never was a second round fired in the FACW.

Did UUCP sites play similar games with dialup?

Jack Haverty


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