On (2013-02-11 12:16 +0000), Aled Morris wrote:
I don't see why, as an ISP, I should carry multiple, identical, payload packets for the same content. I'm more than happy to replicate them closer to my subscribers on behalf of the content publishers. How we do this is the question, i.e. what form the "multi"-"casting" takes.
It would be nice if we could take advantage of an inherent design of IP and the hardware it runs on, to duplicate the actual packets in-flow as near as is required to the destination.
Installing L7 content delivery boxes or caches is OK, but doesn't seem as efficient as an overall technical solution.
As an overall technical solution Internet scale multicast simply does not work today. If it did work, then our next hurdle would be, how to get tier1 to play ball, they get money on bits transported, it's not in their best interested to reduce that amount. Now maybe, if we really did want, we could do some N:1 compression of IP traffic, where N is something like 3<10. Far worse than multicast, but with this method, we might be able to device technical solution where IP core does not learn replication states at all. We could abuse long IPv6 addresses DADDR + SADDR + extension header to pack information about destination ASN who should receive this group, this could be handled without states in HW in core networks, only at ASN edge, you'd need to add classic multicast state intelligence. -- ++ytti