Subject: [Softwires] With 6rd, reducing the number of assigned ports needs not be difficult

From: Rémi Després <[email-masked]>
Date: Thu, 28 Jul 2011 16:12:04 +0200

Alain,

Unless I misheard, you said yesterday in the Softwires meeting that you thought it whould be difficult to reduce assigned numbers of ports in a completely stateless solution (without per customer state in BR's).

AFAIK, this isn't difficult with the 4rd stateless address mapping. It would only require a slight amendment of the current spec. Thus, a reduction of the number of ports of a particular customer, or of a class of customers, is done by increasing the length of its assigned IPv6 prefix(es). Thus, each bit added to the IPv6-prefix length divides by two the number of ports. Details of the amendment can be discussed in due time.

In many typical environments, the fact that each port-set reduction is at least a division by 2 shouldn't be AFAIK a problem . (Address prefixes have always defined addressing spaces whose sizes vary by 2^k factors.)

Regards,
RD