Hi Qiong, On 2011/08/04, at 18:40, Qiong wrote:
> Hi Remi, Tetsuya, > > Thank you for your reply. Please see inline. > > Thousands of rules seems to me a lot. > (I keep doubts that, if CE's support statically shared addresses, keeping > thousands of IPv4 prefixes would be needed to support IPv4 via IPv6.) > In any case, this can be among factors that differentiate which solution > applies best to which network. > > [Qiong]: Agree. > > Adapting a CE to up to 1000 rules doesn't seem difficult to me, and with > O(log n) matching this can be done with satisfactory performance. > (More details would be private consultancy ;-)). > > [Tetsuya] Thousands of rules sounds a lot to me as well. But I don't > think it is difficult for CE to support such a number of rules. In fact, > our implementation was tested under 10k rules in our lab. > > [Tetsuya] Also, the rule consists of Domain IPv6 prefix/length, Domain > IPv4 prefix/length, CE IPv6 prefix length and Domain IPv6 suffix/length. So, > the total data size of these tuples is 40bytes roughly. So, if using 1000 > rules, the total data size is roughly 40kbytes. So, I don't think the big > chunk of memory is not required for storing all of rules in CE. > > > [Qiong]: I can fully understand that rule matching algorithm would not be > difficult to handle 1000 rules. But we should still keep in mind that > traditional CPEs are usually embedded systems with restricted resources. The > amount of NAT sessions it can handle is approximately about 2000~3000. When > we add another 1000 rules to do prefix matching in CPE, I think it would > still cost more than before. Agreed. Some of traditional CPEs might not be able to handle a bunch of NAT sessions due to the resource limitation such as memory, cpu, etc. From the implementation point of view, I think the required resources for 4rd mapping rule is smaller than the resources for NAT session because usually NAT session contains many information. > BTW, what's the output performance of your algorithm apart from memory > occupation and what's the configuration of your platform in your test ? Did you asked about the forwarding performance? We used netbsd running on arm core cpu (400MHz). The accrual ratio of the latency is just 2 to 5 % under 4rd environment. Thanks, Tetsuya Murakami > At the same time as other parameters (once in awhile to avoid lifetime > expiry). > > [Qiong]: I think in this case, we would need another specification to > distribute this rules automatically. > > > Thanks > > Best wishes > > Qiong Sun >
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