[pcp] Comments on draft-ietf-pcp-dhcp-03

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

After reviewing draft-ietf-pcp-dhcp-03 I believe there are some things I
believe we need to tie up.

When a PCP Client contacts PCP Servers in parallel, say, IPx1, IPy1 and
IPz1 as mentioned in draft and all respond then:

1 - What happens to the state in y1 and z1 if PCP Client chooses x1 to
communicate? Probably let it age out or delete mappings.

2 - If there is a failure on x1 and PCP Client decides to communicate with
y1, there might be some 'leftover' mappings for internal IP:port (see 1).
PCP Client will need to delete or reuse existing state in y1. Important to
notice that there is no way to guarantee that PCP Server will allocate
same external IP:ports.

3 - I guess it is assumed that if PCP Server is co-located with NAT, if x1
fails, traffic (PCP and data) will be diverted to y1.

4 - Related (2). The draft says that when a PCP Server is unreachable
(say, y1) PCP Client will continue to try to communicate even though other
PCP Server are available.  The only way to 'communicate' is sending a
request, which might create state. So, when y1 is back up. y1 might
allocate a different external IP:port than other server.

Thanks,

Reinaldo