Subject: 232-Addresses not only for current SSM model

From: Hummel Heinrich <[email-masked]>
Date: Wed, 2 May 2001 14:46:16 +0200

Hello,

	The 232/24-address space is reserved for source-specific multicast. An address G from this address space only uniquly identifies a multicast channel
	together with a particular source's unicast address S.  

	Application: multicast model according to the SSM WG.

	1) 
	This is really great for many very good reasons.

	2)
	A particular source of unicast address S does not head  2**24 SSM-multicast channels. Therefore, a subrange would do as well.

	3)
	I can imagine further multicast models in the future, which would be happy to use a 232/24-address, but which
	would use different protocol procedures, protocol messages, protocol TLVs. 
	Just one example:
	A completely different mulitcast delivery channel could be a ring. As a matter of fact, a ring needs only about 20 % more hops than a Dijkstra-tree.
	The information can be sent out in two directions so that in case of a link failure, each receiver node would get the information at least once.
	Furthermore, in case of optical networks, the power of light is preserved in a better way.
	Of course, a ring could be extended to a "tree of rings" or a "ring of rings".
	 
	 I am quite sure that other folks have further ideas. People do not stop thinking about multicast just because the SSM work is done.

	For all such reasons: Isn't it  appropriate to reserve a subrange of the 232/24- address space for SSM?

	Regards,
	Heinrich Hummel
	Siemens AG