[pcp] Comments on draft-tsou-pcp-natcoord-08

["Reinaldo Penno (repenno)" <[e-mail]>]

Hello Authors,

I reviewed this draft and my general comments are below, mostly related to
the motivation and proposed solution.

The draft states the following:

"
1.  Application Scenario

   PCP can be used to control an upstream device to achieve the
   following goals:


   1.  A plain IP address (i.e., a non-shared) can be assigned to a
       given subscriber because it subscribed to a service which uses a
       protocol that don't embed a transport number or because the NAT
       is the only deployed platform to manage IP addresses.

   2.  An application (e.g., sensor) does not need to listen to a whole
       range of ports available on a given IP address.  Only a limited
       set of ports are used to bind its running services.  For such
       devices, the external port(s) and IP address can be delegated to
       that application and therefore avoid enforcing NAT in the network
       side for its associated flows.  The NAT in the PCP- controlled
       device should be bypassed.

   3.  A device able to restrict its source ports can be delegated an
       external port restricted IP address.  The PCP- controlled device
       should be instructed to by-pass the NAT when handling flows
       destined/issued to that device.
"

In both 2 and 3 NAT could be performed by PCP controlled device. There is
no discussion of this aspect (maybe due to Lw4o6 drivers) but if the
mechanism is to be generic, we need to define how it would work. As I
think about it , it seems there are quite a few issues to be ironed out.

Thanks,

Reinaldo