[comp.protocols.tcp-ip] Something has changed dramatically

dpk@BRL.ARPA (Doug Kingston) (07/17/87)

	Internet performance has soared to some of the best I have
see all year.  I have been able to successfully access Berkeley and
UCL is finally available again.  I would like to thank whoever is
responsible for the recent change of events and to suggest that
perhaps a status update is in order.

Putting away my UUCP,
	-Doug-

CERF@A.ISI.EDU (07/17/87)

Doug,

Voodoo networking! (George Bush theme for the 88 campaign?)

Maybe someone sacrificed a chicken over RFC 1009?

Added some links?

Your puzzlement points out that we lack any global view of the
Internet and don't even have a good way to figure out when we
should report changes we've made in some part of the system or
to whom such changes should be reported.

Sounds like a good INENG topic, to me.

Vint

scohn@ALEXANDER.BBN.COM (Steve Cohn) (07/17/87)

Here's something that changed. BBN modified the metric used for calculating SPF
routes in the Arpanet on Sunday, 12 July. A detailed description and analysis
of how it works and a report on measured changes in performance in the Arpanet
will be forthcoming eventually. In brief, this change in the metric leads to
more stable routing behavior when the network is overloaded, thereby reducing
the tendency for congestion to spread from overloaded paths to the rest of the
network. This modification also tends to make satellite trunking more
attractive.

Other potential sources for improvement include recent topology changes
including the addition of transcontinental VSAT trunks between MIT-77 and
SRI-51. These trunks became operational about 1 July.

The routing effort is still in the experimental/tuning stage. We expect that
performance on many PSN-to-PSN flows will be improved by this modification. It
is also possible that some PSN-to-PSN flows will receive degraded performance.
We at BBN would like to hear both the good news and the bad news. Please send
your observations about recent changes in internet/Arpanet performance to Fred
Serr (fserr@bbn.com), Bob Pyle (rpyle@bbn.com) and myself (scohn@bbn.com) and I
suppose to the list if your observation is of general interest.

Stephen Cohn
Director of Network Analysis
BBN Communications

hinden@CCV.BBN.COM (Robert Hinden) (07/17/87)

Vint, Doug,

Its not voodoo networking, but lots of hard work.  There have been
several changes on the Arpanet (new line and a software patch) which
make things better.  These changes are very recent.  A more detailed
report will be seen soon.

Regards,
Bob

SRA@XX.LCS.MIT.EDU (Rob Austein) (07/17/87)

The third transcontinental link (MIT77 <=> SRI51) came online about
two weeks ago.  I noticed a serious DECREASE in performance just after
the link came up, but now I too am seeing a major performance
improvement (it's been a long time since I could FTP from MIT to
Stanford at noon on a Friday!).

My guess is that there were some initial tuning problems after the new
link came up; not too surprising given that this is a satellite bounce
instead of a land line.

Presumably somebody at BBN can give a more detailed report.

--Rob

weltyc@NIC.NYSER.NET (Christopher A. Welty) (07/19/87)

	Hard work indeed.  I too have noticed significant improvement
in ARPAnet performance.  THose resposible should be congratulated!

---

Christopher Welty - Asst. Director, RPI CS Labs
weltyc@cs.rpi.edu       ...!seismo!rpics!weltyc