RE: [802.21] transport layer for MIH IS.
Stefano,
When do you expect .21 to be deployed? We already have 802.3, 802.11, and
3GPP/3GPP2 technology been widely commercially used, and the product with
multiple wireless media interface is merging, so I believe the market expect
to have a standard like 802.21 ASAP, right? I believe how quick this
standard can be commercialized and how easy to this standard be implemented
in current or early future network is important for .21 to be success.
Regarding the scope, I just afraid that if we don't give some guideline or
specification, it will bring the confusion and complexity for actually
implementation, e.g the ST uses one IP application to transfer SI to .11
network, then handovers to another network(.16),it uses MAC management
message for IS, and then if handover to another .11 network with using .11
L2 layer for IS. What a mess it will be.
Regarding IP layer, I don't mean we create another IP protocol, but a IP
application, such as Telcordia & Toshiba proposal to use SIP. So, we don't
need to deal with IETF but we can define ourself.
Regarding the robust of L2, e.g for a situation, the IP connection or IP
service is unavailable, but ST still can communicate with network with its
L2.
David
-----Original Message-----
From: owner-stds-802-21@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-21@LISTSERV.IEEE.ORG] On Behalf Of Stefano M. Faccin
Sent: Thursday, January 20, 2005 5:05 PM
To: STDS-802-21@LISTSERV.IEEE.ORG
Subject: Re: [802.21] transport layer for MIH IS.
David,
as Perez says, we must realistically expect that 802.21 signaling (remote
events, etc.) will be implemented both with IP-based solutions and L2
specific solutions. The reason is quite straightforward: do you want to
deploy 802.21 ASAP? Well, use an overlay solution where transport is 802.21.
If we rely just on L2, it may take a long time before anybody can actually
use 802.21. Whether somebody is interested in the IP transport or not is
another issue. Now, the two real question is whether or not all this
discussion is in the scope of 802.21. As I mentioned in my slides, I believe
802.21 shall not define any transport, only logic of MIH functions,
interfaces, IEs, etc. 802.21 can develop recommendations for the specific
link layer groups and for IETF, 3GPP or 3GPP2 on how to take the outcome of
802.21 and implement it, but I don't see how 802.21 can define such
implementation. As Perez says, if transport over IP is to be defined, IETF
is the place to go. How specifically this!
will be done is out of scope of 802.21.
David, I also have the same question that Ajoy has: why do you believe L2
transport is more reliable?
Stefano
-----Original Message-----
From: owner-stds-802-21@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-21@LISTSERV.IEEE.ORG]On Behalf Of ext David Xiang
Sent: Thursday, January 20, 2005 5:23 PM
To: STDS-802-21@LISTSERV.IEEE.ORG
Subject: Re: [802.21] transport layer for MIH IS.
I mean how to transfer the IS through air-interface. Is the IS carried in IP
play load which doesn't care what media interface carrier it or direct in L2
payload of that specific media interface (e.g IE of MAC management message
for 802.11, 16)?
David
On 1/20/2005 3:30 PM, David Xiang wrote:
> When we consider the complexity of .21 implementation and interaction with
> other media standard, we need to think of our transport layer for
> information service exchange with network or peer, though it seems out of
> scope of .21 from most of the proposals.
> I saw two ideas of transport layer from the proposals: IP application, and
> L2. I just want to get your thoughts on which one is better.
Transport across network elements must be IP type, which of course is
carried
within L2 Ethernet frames.
In .21 new Ethernet frames (type .21) is in scope, IP is questionable. It
may be
an IETF domain to pick form the .21 standard.
>
> IP:
> Pros: 1. Generic and less impact on other media standard,
> 2. Give more implementation flexibility for .21 information service
> and other requirements.
> 3. More easy to be implemented.
>
> Cons: 1. slow
> 2. Not reliable or robust as L2 transport, but IP application can
> become robust with some good mechanisms.
>
> L2:
> Pros: 1. faster
> 2. More robust
>
> Cons: 1. Too rely on other media standard which may not good for .21
> implementation.
> 2. Not flexible, any time .21 do some changes on SI, it may request
> all other media standard to do some changes too.
>
> Any thoughts?
It is not one or the other, it will have to be both if we include MIH
exchange
between a station and MIH IS DB at the core network.
The big question is how do we define the IP protocol associated with the
exchange of IP messages between the terminal and the IS network element? is
it
an IETF follow up? or within the scope of IEEE802.21?
>
> Thanks,
>
> David