Re: [DNA-BOF] BoF Last Call on DNA WG Charter.

[Alper Yegin <alper@docomolabs-usa.com>]

> So one might make a case that
> there is some value at L2, although most of the current L2 link-Id
> proposals don't seem to adequately take into account the dynamic nature of
> VLAN assignment today.  This means that an L2-advertised Link-Id is only a
> "strong" hint if it is advertised after the VLANID has been assigned.
> Prior to that point, it is just a "weak" hint because the assigned VLANID
> could turn out to be different than the one being announced at L2.

This is not what we have in the dna-l2-hints draft, but now I'm thinking
maybe we should be talking about two different identifiers in this context.

One is the physical link ID. This can be based on the access point ID in
802.11, SGSN ID in GPRS, RAN ID in 3GPP2. In most of the cases, there is no
one-to-one mapping between the physical link ID and the network-layer
configuration parameters. This ID just identifies a physical association.

The other is the network ID. For example, VLANID in 802.11, IP
address/subnet obtained in PDP context in 3GPP or via PPP in 3GPP2. This
identifies a logical association between the host and an IP subnet.

Now, when a link-layer event (e.g., link up) takes place, it should be
associated with a physical link ID and possibly with a network ID. Network
ID is optional as this info might not be available all the time (e.g., when
VLANID is not available).

If a network ID is available, the host can quickly determine if it has
changed subnet. If a network ID is not available, it has to play safe and
perform network-layer discovery to detect if it needs to reconfigure.

Comments?

Alper