RE: GSE IDs [Re: IETF multihoming powder: just add IPv6 and stir]

["Christian Huitema" <huitema@windows.microsoft.com>]

> One way of addressing this particular concern is to say the top 48
bits
> are mutable from one globally unique value (a "site identifier") to
> another globally unique value (an "aggregation locator") via some
> mapping function at both exit from the source site as well as entry at
> the destination site.

The focus on the site misses an important point. Computers are often
multi-homed to several sites, e.g. WiFi and GPRS. If you do something as
radical as changing the behavior of TCP, then you want a solution that
handles host multi-homing as well as site multi-homing. But then you
cannot expect that all the "locators" that carry packets to a single
TCP++ solution belong to the same aggregate.

In the site multi-homing case, you must also be concerned with privacy
issues. You should not force multi-homed computers to attach the same
"global identifier" tag in all of their IP addresses, and you may expect
privacy advocates to forcefully remind you if you ignore that point. 

Having a 16+16 solution a la Mobile IPv6 may be fine, provided that the
privacy-conscious can encrypt the correlation identifier (the second 16)
in an encrypted exchange. And it would also be nice if the second 16 did
not have to be present in every packet.

-- Christian Huitema