Subject: Bandwidth Limit

From: Kathy Hewitt <[email-masked]>
Date: Sat, 24 May 1997 12:56:17 -0400

Hi there!  Quick question: is the 500 Kbps bandwidth limitation for MBone enforced through the mrouters or is that etiquette?

I ask this because I'm looking at a product from SUN called Lyceum and am interested in using it for our real-time distance education program here in North Carolina.  Everything we have done has been kept at a TTL of 63 so it remains in NC.  Lyceum supports multicasting but advises not to use it over the MBone since it uses 500Kbps of bw.  We were wondering whether we could still use it in the state of NC where we use the NCIH as our backbone.

Thanks a lot!

--Kathy Hewitt

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From: John Meylor <[email-masked]>
Date: Sun, 25 May 1997 11:13:50 -0700

> Hi there!  Quick question: is the 500 Kbps bandwidth limitation for MBone enforced through the mrouters or is that etiquette?

There is a draft working its way through the IETF now which can
best answer this first question:

ftp://ietf.org/internet-drafts/draft-ietf-mboned-limit-rate-guide-00.txt

I ask this because I'm looking at a product from SUN called Lyceum and am interested in using it for our real-time distance education program here in
North Carolina.  Everything we have done has been kept at a TTL of 63 so
it remains in NC.  Lyceum supports multicasting but advises not to use
it over the MBone since it uses 500Kbps of bw.  We were wondering
whether we could still use it in the state of NC where we use the NCIH
as our backbone.

In general, 500K "can" be a lot of traffic from one source on the 
global mbone due to under-engineered areas of the global topology.
This may be due to low-bandwidth links in your path, or in-adequate
HW/SW at the network devices. Depends on where you expect to have
sources and receivers for your project.

However,
If you are indeed planning on keeping the traffic on NC nets
(ie isolated on an autonoumously administered system like NCIH, AS
6559), then the rate you should source at is really up to the 
adminstraters of those networks.  This is good because you may
be able to source more than you could over the "interdomain"
portions of the mbone or portions of an externally administered 
network.  For some of our internal projects, we can source the
multicast at 500K (and more) easily without problems.  
 
So I would recommend directly contacting NCIH.I believe the 
coordinator for NCIH is Mark Cooke <[email-masked]>. 
It also looks like you may be using the NC  Research and
Education Network ? so you may want to contact Richard
Misenheimer <[email-masked]>,
or Peter Cassels <[email-masked]>.

Good luck, sounds exciting !

- John Meylor
NASA Internet
NASA Research and Educaton Network