nanog mailing list archives

Re: Multicast Internet Route table.


From: Corey Touchet <corey.touchet () corp totalserversolutions com>
Date: Tue, 2 Sep 2014 15:29:26 +0000

14 years at Verizon Wireless and I despised the crop of multicast products
that seemed to pop up from time to time.  Even in a fully controlled
network multicast remains at best black magic.  There are ways to make it
more reliable and prevent people from ruining the setups especially for
PIM type setups, but I would agree with others, unicast has better
advantages though you have to keep up with the bandwidth curve.  Content
delivery systems moving the content closer to edge customers makes this
less of a problem as well.

Torrent style distribution appears to be particularly effective as long as
you can maintain a pool of users to distribute the content.  Blizzard has
made good progress using this for game updates will a fallback to http if
you canĀ¹t get the content via torrents.




On 9/2/14, 6:46 AM, "John Kristoff" <jtk () cymru com> wrote:

On Tue, 2 Sep 2014 04:47:37 +0000
"S, Somasundaram (Somasundaram)" <somasundaram.s () alcatel-lucent com>
wrote:

1: Does all the ISP's provide Multicast Routing by
default?

No not all and even those that do often do not do so on the same gear,
links and peers as their unicast forwarding.

2:  Is there any placeholder where one can get to know the
Multicast Internet Route table (usage, stability etc) just like
Unicast Route table (http://bgpupdates.potaroo.net)?

Marshall Eubanks at one time probably maintained the most comprehensive
IP multicast status pages at http://www.multicasttech.com/status (no
longer available).  I've not seen nor heard from Marshall in a long
time so I wouldn't expect this to come back any time soon.

Sadly I don't know of any suitable replacement, but you might find some
of that by searching here, if nothing else using the router proxies to
examine status by hand:

 <http://noc.net.internet2.edu/>

CAIDA used to do some, but I'm not sure they have anything active any
longer, browsing their tools and data may turn up some hints to other
work.

The once NLANR inspired and run Beacon project hasn't completely died
out, there is this I found at ja.net for instance:

 <http://www.beacon.ja.net/>

Interdomain IP multicast has practically since the beginning
been a notoriously niche and limited service compared to unicast
service.  There are a handful of reasons for that, but I think you will
find it becoming decreasingly available rather than more so on
interdomain basis.

John


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