On Tue, Mar 16, 2004 at 08:54:30PM -0600, Stephen Sprunk wrote:
Thus spake "Scott Michel" <scottm(_at_)cs(_dot_)ucla(_dot_)edu>
On Tue, Mar 16, 2004 at 07:09:12PM -0600, Stephen Sprunk wrote:
When you add in the (assumed) requirements of backwards compatibility
with existing routers and hosts that don't implement a proposed
extension,
it gets messy real quick.
The immediate handwave would be "Tunnel it." I'm not denigrating
backwards compatibility, but a lot of good work has relied on tunneling in
the past, e.g., Mbone and v6-v4. I'm currently waiting with baited breath
the day that service providers provide v6-to-v4 as the special case to
v4-only hosts.
The Mbone and 6bone are different beasts, as they're about tunneling traffic
from capable hosts across an incapable core. In the case of an identity
layer between IP and TCP, we would need to be backwards-compatible with
non-capable hosts and applications (not just non-capable routers) and so
tunnels don't seem a workable solution.
Tunnelling can exist at multiple layers. Overlays are just a different
version of tunnelling. Proxies can be viewed as a very limited form of
application tunnelling. Dealing with the complexity of different tunnelling
methods and requirements makes my handwave less tractable (which was
actually more to my point.)
You never know until you submit a proposal what DARPA **really** wants
even after you get through the program-speak.
All too true. We do, however, know many of the IETF's needs in the
identifier/locator arena, e.g. for Mobile IP and IPv4/6 multihoming. That
may be a good starting point to determine what, if any, additional
requirements DARPA has.
No argument there.