[shara] port randomization (draft-ymbk-aplusp-03)

["Dan Wing" <[e-mail]>]

http://tools.ietf.org/html/draft-ymbk-aplusp-03#section-4.8 says, in part:

   ...
   Port randomization is also a bit compromised in A+P solution.  As CPE
   can randomize ports only within port range that is allocated to it,
   randomness is more limited than in the the scenario with full range
   of ports, allowed for randomization.  We can assume, that CPE either
   gets port range from ephemeral range (49152-65535) or from
   "registered ports" range (1024-49151).  Both ranges can be used for
   randomization, see [I-D.ietf-tsvwg-port-randomization] for more
   details.

Has consideration been given to having the PRR return only *one* port
for each request, or to returning a list of port numbers which are
not consecutive and are not a bit-pattern of ports?  These techniques
would allow the PRR to distribute the requests randomly across the 
entire port range instead of within a block of ~100 (or whatever). 

Further fleshing out of the technique described in Section 4.4
("Dynamic allocation of port ranges") could be useful towards 
allowing applications to benefit from the security advantage of 
port randomization.

-d