RE: Multicast Data

Hi Tharin,

Good point!
First off, I'm hoping that my interpretation of your question is correct
anyway correct me if your question if not exactly this but actually the
problem is that almost all resources (including most pages on cisco.com and
juniper.com as well as the RFC!) focus on the "second" action taken by the RP
after receiving the registration request! and the first (but the less
important action) is somehow ignored (or underestimated)....

Here is the process (briefly):

Your Windows 2003 Media server starts sending the Multicast packets of (analog
term : broadcasting) "The Family guy". The first Mcast packets hit their
gateway and the DR of that segment tries to get a hold of the RP to kick off
the registration process. You know the encapsulation process (the actual mcast
content inside a unicast packet - right?) so the RP gets the first capsule and
"extracts" the multicast content. At this stage the RP has to take two
actions:

1- It sends the extracted Multicast packet down the tree based on the (*,G).
Where did you get that from? my Visa client had talked to his DR and his DR to
his upstream then to his upstream...all the way up to the RP to indicate his
interest. So before getting the first packet (the capsule) as you mentioned
the RP does know that I'm waiting to watch Quagmire (there is a receiver down
there). In fact the (*,G) is on the RP waiting for the source to come up.

2- The RP then tries to join the group and now everyone knows what's gonna
happen afterwards...I save some key strokes.

Well, as you see (the first action), even the first packet (probably the first
frame of the Fox ad!) is delivered by the RP to (*,G) to ensure nothing's
going to be missed.

HTH

Kambiz Agahian
CCIE (R&S)
CCSI, WAASSE, RSSSE
Technical Instructor
CCBOOTCAMP - Cisco Learning Solutions Partner (CLSP)
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-----Original Message-----
From: nobody_at_groupstudy.com on behalf of Tharindu Rukshan Bamunuarachchi
Sent: Thu 4/8/2010 10:04 PM
To: ccielab_at_groupstudy.com
Subject: Multicast Data

hi Experts,

In sparse-mode, AFAIK first packet is forwarded to RP as unicast. (In
Register Unicast process).

Is there any possibility to lose first packet without being delivered to
destination. (assuming destination is already subcribed to multicast tree)?

__
btharindu.blogspot.com

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Received on Thu Apr 08 2010 - 23:44:36 ART