Note that although CLNP use Node Identifiers, these were coupled to
subnet locators. That is, the NSAP specifically identified the subnet
to reach the host on. Further, out expectation was that a preamble to
the NSAP would be the service provider providing connectivity. SO that
the NSAP was a topologically sensitive address, with a NODE identifier
as the last portion.
(Yes, there are parallels to some of the other ideas this research group
has discussed. We did not take that work anywhere near there at the time.)
Yours,
Joel
Dae Young KIM wrote:
On Sun, May 23, 2010 at 2:06 AM, Noel Chiappa <[email protected]> wrote:
> From: Dae Young KIM <[email protected]>
> the role of PoA is already served by MAC address, and not has to be
> duplicated by extra 'Locator'.
i) Not all networks have a MAC (although most do, now).
ii) A MAC serves to globally _identify_ an interface, but it is not enough to
_locate_ it (i.e. to be useful to the path selection). It will be necessary
to add some extra information, such as a structured name of the network the
interface is connected to, to make it an interface name which the path
selection (routing) can use. After all, if you do not have that extra
information, you basically have a world-wide bridged network.
Not necessarily. I think I can build a sound network topology only
with node addresses. CLNP, for example, didn't need interface address
to do routing.
Remember, my question was in the context of a node which has _two_
interfaces, to widely separated (in network connectivity terms) networks,
such as i) a particular wireless LAN, and ii) a 3G cellular network.
Why should it be a problem in my picture?:
- At inter-net level, my node will have two links each pointing to a
remote router at the other surface of either LAN or 3G.
- LAN will identify one of the interface with its MAC address while
3G will do the other with its L2 address(whatever it is).
> mobility is inherently supported by routers without resorting to extra
> mapping (ID>Loc) or agent(HA/FA) infrastructure.
Only within an AS. What happens if the node leaves the AS (perhaps to a
different wireless LAN)?
Moving across LANs within an AS won't affect its fast mobility.
There'll surely be a problem in fast mobility when a node leaves an AS
for another AS:
o In its most primitive fashion, the TCP connection would break.
You have to reconnect.
o A fast inter-AS context-switching mechanism might be devised.
o DNS should be updated with a new mapping, name > (addr, AS-new).
This, of course, is a challenge; DNS synchronization is slow. How to
work around this?
I have yet to work on these inter-AS mobility issues. Hope I won't totally fail.
Noel
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