nanog mailing list archives

mbone/NSFnet migration (fwd)


From: bmanning () ISI EDU
Date: Thu, 20 Oct 1994 05:31:53 -0700 (PDT)


If we end up w/ a few minutes this might be a useful topic of discusssion .. :)

Subject: mbone/NSFnet migration
Date: Wed, 19 Oct 94 22:50:18 -0400
From: "Matt Mathis" <mathis () pele psc edu>
X-Mts: smtp


Hopefully most of you are aware of the pending massive restructuring of the
U.S. Internet (see footnote (1) below if not).  In a few idle minutes (ha!) I
attempted to extrapolate the existing mbone onto (my limited understanding of)
the brave new North American Internet topology.

First the good news: When everything is done, the existing mbone will match
new topology far better than we deserve to expect, perhaps almost optimal,
needing only a few minor tweaks.  This was a real surprise!

Naturally during the transition, this will not be the case: unless two
regionals connected by a tunnel move to their new National Service Provider at
the same time, the tunnel between them will temporarily pass through an
interconnect (a Network Access Point) between the NSPs.  Since all regionals
are going to be making the transition at different paces, the intermediate
states are likely to be pretty ugly, with possibly a dozen or more tunnels
crossing the NAPs.

It is hard to predict if this will be a problem.  The aggregate bandwidth
through the NAPs will be quite large - hundreds if not thousands of megabits
per second (see 2), so even two dozen copies of the mbone may be ok.  I would
not do anything drastic, such as shutting down the mbone (even temporarily).
However, if there are problems we MUST be prepaired to adjust the mbone's
bandwidth rating.

Now the bad news: the the transition schedule is already slipping, and the
slippage has widened the spread in expected transition dates.  The original
cut off date for the existing NSFnet service was October 31th.  It is being
extended on a month-by-month, peer-by-peer basis.  Most connections have
already been extended to Nov 30, which is less than a week before the
IETF......

The situation is complicated be two other issues: the Internet itself is going
to be rather fragile during the transition.  Although hundreds (thousands?) of
people have been working very hard on it, there is just too much new
technology, infrastructure and hardware for the transition to be totally free
of glitches.  There will be mbone outages that are due to IP failures
unrelated to mbone traffic.   It may be very difficult to tell if the mbone is
contributing any observed instability.

Furthermore, most of the contacts on the mbone provider list are already
working overtime on the Internet transition.  If some regional is having
problems with vanilla IP service, mbone problems will be secondary.

So, what can the research community do to help?  I can think of several things:

o Dust off mbone mapping, instrumentation and diagnostic tools - particularly
      "strip charts" for mbone load and route transitions per hour, so we
      have a "before" baseline, and can correlate route flaps with load.  If
      data storage is a problem let me know, and I can make some
      arrangements.

o Be patient when it is broken, and be aware that the the person who needs to
      fix it may have already been up all night.

o Be gentle with the bandwidth, or it may be discovered that is your bits were
      the "last straw".

o We need to have some administrative mechanism to come to a consensus about
      mbone capacity.  The scheduling tools are a nice idea, but how do you
      know how much BW you have to divide under conflicting reports of
      signal quality.

o Don't start a conversation about the tunneled vs native multicast.  We've
      been there.

I will be posting an updated mbone provider contact list sometime soon.

Sorry about the duplicate posting, but I believe that both the mbone users and
providers need to be aware of what is going on.

--MM--

----------------------------------------
Footnotes:

(1) To make a long story short, the existing NSFnet is a service of one
provider: Merit, with one prime subcontractor: ANS.  NSF is spending a large
sum of money to provide "free" T3 connections to the regionals.

After the transition, the NSF money will flow directly to the regionals (with a
builtin 5 year sunset), who must purchase connectivity from NSF certified
National Service Providers.  The primary requirement to be a NSP is that they
connect to the NSF awarded NAPs, which are for exchanging traffic between
providers.  (Much detail omited....).  In addition there are some Independent
Service Providers, who are selling a la cart connectivity, mostly to
businesses, etc.  They may also connect to the NAP's but unless they meet the
NSP certification, they are ineligible to directly carry NSF funded regionals.
Note that no NSF money goes directly to the NSPs, NAPs, or ISPs.  They get
all of their revenue by charging for their services.

The up-to-date status can be obtained under http://rrdb.merit.edu/home.html.
Note that the intended audience is the service providers, who do not need
introductory explanations.

(2) The aggregate bandwidth available within the NAPs is surely
gigabits/second, but most (all?) NSPs will connect via T3 links to 3 or 4
NAPs for a total usable IP bandwidth of no more than 160 Mbit/s.  I am not
privy to any of the global traffic models, so I can not comment on the
expected load on these links.




-- 
--bill
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