Subject: [Softwires] Sharing a Basic Mapping Rule in draft-ietf-softwire-map-03.txt

From: Tom Taylor <[email-masked]>
Date: Sun, 27 Jan 2013 10:13:24 -0500

Section 5.2 talks about BMRs being shared amongst CEs. This is only 
possible with certain restrictions, which should perhaps be enumerated. 
Fundamentally, anything unique to a specific CE MUST be provisioned 
separately instead of being part of the BMR. Hence:

- In the case of a shared IPv4 address, the PSID MUST be provisioned by 
other means.

- In the case of an IPv4 prefix or full IPv4 address, one could 
theoretically share BMRs, but the CEs concerned would have distinct IPv4 
prefixes which MUST be provisioned by other means, combined with 
suffixes (in the EA bits) which are common to the sharing CEs. This 
seems like a peculiar thing to do in practice. It would be simpler just 
to say that if BMRs relating to IPv4 prefixes or full IPv4 addresses are 
shared, the EA bits MUST be absent (o = 0). Even simpler: forbid sharing 
of BMRs for IPv4 prefixes or full IPv4 addresses.

BTW: potential global change: instead of "full address", how about 
"unrestricted address"?

Tom Taylor

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From: Tom Taylor <[email-masked]>
Date: Sun, 27 Jan 2013 10:19:43 -0500

Oops. Got mixed up between the Rule IPv6 prefix and the end-user IPv6 
prefix.