Re: [802.21] [DNA] Prefix information for link identification in DNA
Hi Andrea,
Thanks a lot for your effort to carefully defining the terms. I am in
favor of the new definition with defining "link" and "PoA" in strict
L2 sense. Also, I like the new term PoS for representing a
network-side MIH-capabile node, which totally makes sense to me to
differentiate between MIH-enabled UE and its counterpart.
I have just one comment, please see at the bottom.
On Mon, Oct 03, 2005 at 06:02:39PM -0400, Andrea Francini wrote:
> Hi Yoshihiro,
>
> I agree with you that the notion of adjacency I am using also applies, in the
> case of UE1, to UE2 and UE3 (and not only to the AR). However, the PoA
> definition also includes a "network-side" qualifier that does not apply to UE2
> and UE3 and still allows (if really needed) to distinguish the AR from UE2 and
> UE3.
>
> I understand you mostly oppose the notions of "L3 PoA" and "L3 link". Let's see
> if we can get rid of them with the following:
>
> 1. We define "link" and "PoA" in strict L2 sense.
>
> 2. We avoid any link-like or PoA-like definition for L3.
>
> 3. We define the "MIH Point of Service (PoS)" as a network-side counterpart of
> the UE for the exchange of MIH information, and the "MIH pairing" as the
> relationship that exists between MIH-enabled UE and MIH PoS when they exchange
> MIH messages/information.
>
> With the above arrangement:
>
> A UE attaches to a network through a link that terminates at a PoA. (No L2
> qualifiers needed for "link" and "PoA".)
>
> The UE exchanges MIH information with MIH PoS's. Generally, the MIH PoS resides
> at an interface on a network node with which the MIH function of the node is
> registered for MIH services. An MIH PoS may or may not be co-located with a PoA
> on the same (L2) interface.
>
> It can happen that an interface on an MIH-capable node (i.e., a node that
> contains an MIH function instance) does not host an MIH PoS because the local
> MIH function is not registered with that interface for MIH support. However, an
> MIH PoS may still be found in the same network node at a different interface.
>
> The UE may use L2 transport for exchanging MIH information with an MIH PoS that
> is co-located with a PoA.
>
> The UE must use L3 transport for exchanging MIH information with an MIH PoS that
> is not co-located with a PoA.
I think the "must" in last sentence might be "may" for the following
reason.
In the example below, I think the UE could still use an L2 transport
for exchanging MIH information with the MIH PoS if the MIH transport
is defined on top of LLC (which is still L2) and the MIH PoS supports
the L2 transport. The non-PoA MIH PoS may be implemented on the
particular Ethernet interface of an IP-capable or IP-incapable node.
802.11 link Ethernet link
UE --------------------- AP ------------------- non-PoA MIH PoS
Best regards,
Yoshihiro Ohba
>
> Thanks,
>
> Andrea
>