Re: [sig-policy]Proposal prop-014-v001.txt - Lowering minimum allocation size and criteria

[Philip Smith <pfs@cisco.com>]

Hi Izumi,

Some thoughts...

At 19:07 26/01/2004 +0900, Izumi Okutani wrote:

> Also, they are not direct comments regarding this proposal, but there
> were following comments regarding the route aggregation.
>
>   - wouldn't it still be an issue for ISPs that are not able to afford
>     the latest router? The cost of router memories are very high
>     compared to those of PCs
Only an issue for ISPs who insist and persist in carrying the full routing 
table across their entire network for no purpose other than "because they 
still can". It seems to be a public given that the only way to multihome 
your customer is to give them a copy of the full routing table, along with 
the copy that the other ISP is giving them. If they are forced to carry 
260k paths, then yes, router memory is an issue. There is a simple 
workaround which those who are router memory challenged have been using for 
years.

>   - Latest routers have routing tables in i/f as well, so it cannot be
>     addressed by simply adding memories
Routing tables are stored in memory on the linecards - so if my previous 
comment doesn't apply, yes, memory will have to be added to the linecards too.

>   - Wouldn't it use a lot of CPU to calculate the routes once the peer
>     drops?
Simple answer is "yes". Complicated answer is "it depends". But again, I 
query why it is a given that to be part of the Internet an ISP needs to 
carry 130k prefixes from each ISP it has as an upstream.

BTW, I'm trying to put together an aggregation discussion as part of the 
Routing SIG, where these and other issues regarding the size of the routing 
table will be discussed. Hopefully people will be interested in taking part 
and contributing their thoughts and experiences.

philip
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