[comp.protocols.tcp-ip] X.25 to Milnet PSN problems - the continuing saga

brian@ucsd.EDU (Brian Kantor) (02/05/88)

A few weeks ago I mentioned here that we're having a problem with the
Milnet IMP we're connected to being completely unable to open X.25
virtual circuits to us, so only those VCs that we open to it will allow
data to pass to mailbridges and other hosts on the milnet.

We're still having the problem, and I wonder if anyone else has seen
this happening on their host?  Misery loves company, maybe?

Our interface is an ACC6250 board (in a VAX780 4.3BSD), and the
people at ACC (especially Lars Poulson) have been extremely helpful
in attempting to get this problem resolved, but so far it isn't.

I'm told that a trace in the PSN code shows that the IMP wasn't even
trying to open the circuit to us, so it's probably in or related to the
PSN code and not the interface - especially since it just started
happening without us making and hardware or software changes.  It DID
start around the time the Arpanet cut over to PSN-7, but we're on the
Milnet.

We're currently running a process that sends a single ping packet to
each of the Milnet mailbridges once every 45 seconds to ensure that the
X.25 VC stays open so that traffic will find an already-open VC instead of
blocking because it can't open one of its own.

Now that I've finished crying on your collective shoulders (waah), I'm
wondering if anyone else has seen any evidence of this happening to
them?  I have trouble believing we've been singled out for this dubious
honor.

	Brian Kantor	UCSD Office of Academic Computing
			Academic Network Operations Group  
			UCSD B-028, La Jolla, CA 92093 USA
			brian@ucsd.edu ucsd!brian BRIAN@UCSD

jtn@potomac.ads.com (John T. Nelson) (02/12/88)

In article <7@ucsd.EDU>, brian@ucsd.EDU (Brian Kantor) writes:
> 
> I'm told that a trace in the PSN code shows that the IMP wasn't even
> trying to open the circuit to us, so it's probably in or related to the
> PSN code and not the interface - especially since it just started
> happening without us making and hardware or software changes.  It DID
> start around the time the Arpanet cut over to PSN-7, but we're on the
> Milnet.
> 
> We're currently running a process that sends a single ping packet to
> each of the Milnet mailbridges once every 45 seconds to ensure that the
> X.25 VC stays open so that traffic will find an already-open VC instead of
> blocking because it can't open one of its own.

Well aside from you being on the Milnet this sounds just like our
experiences.  However we have a Sun III/180 running 3.4 of their
operating system with the Sun X.25 DDN software and an SCP board.  Our
PSN is running 7.0 and we talk to it only via HDH (although we are
configured to talk via X.25 "extended").

I run a ping on a host that we peer with every second.

We are still talking to BBN about these problems.



-- 


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Advanced Decision Systems	Internet:  jtn@potomac.ads.com
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