RE: [802.21] Question today about upper layers
-----Original Message-----
From: owner-stds-802-21@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-21@LISTSERV.IEEE.ORG]On Behalf Of ext Peretz
Feder
Sent: Monday, March 21, 2005 12:17 AM
To: STDS-802-21@LISTSERV.IEEE.ORG
Subject: Re: [802.21] Question today about upper layers
On 3/15/2005 9:57 AM, Iyer, Prakash wrote:
> We might want some flexibility here. Having a lower layer autonomously
> switch links w/o considerations for cost ($$), whether it makes sense to
> single-home or multi-home, account for user preferences etc. does not
> seem appropriate - and certainly not in all situations. Having MIH
> generate triggers that facilitate handovers is one thing; specifying how
> MIH can use policies to switch links at this layer is avoidable in
> 802.21.
Not sure what is issue. Why can't the MIH layer get as one of its inputs the
policy attributes? Why is it (policy attribute)
only reserved for an upper layer?
[Stefano Faccin] Peretz, I believe the point here is not that policies and policy attributes must be only reserved for the upper layer, but that realistically it would be rather complex to specify a SAP that allows the UL to provide all the relevant attributes. Through experimenting in Nokia implementations of mobility/connectivity management for multiple access devices, we've witnessed that in order for a terminal with multiple policies - end user, device owner (e.g. enterprise), WISP, cellular operator, application policies/requirements - to make decisions on connectivity and handoff, a rather complex set of interactions between the information available about the links and the policies is required. This led to the conclusion that the logic driving such interaction must be at a layer above the MIH, since such logic can be very complex. Also, it does not make much sense in specifying such logic but allow differentiation between vendors. In particular, we experienced how com!
plex the interactions between this logic and the policies are, and as a direct result if we wanted to allow any logic in the MIH function and the most flexible interaction between the MIH and the policies repository in the terminal, a very complex SAP would result. In conclusion, I see a lot of added complexity without seeing much advantage.
That said, with the base primitives, none of the implementation
> scenarios that people are thinking about will be precluded.
Please elaborate, are you referring to upper layer implementation only
> -Prakash
>
> -----Original Message-----
> From: owner-stds-802-21@LISTSERV.IEEE.ORG
> [mailto:owner-stds-802-21@LISTSERV.IEEE.ORG] On Behalf Of Peretz Feder
> Sent: Monday, March 14, 2005 2:48 PM
> To: STDS-802-21@LISTSERV.IEEE.ORG
> Subject: Re: [802.21] Question today about upper layers
>
> Greg:
>
> I am of the opinion thet MIH commands lower layers to switch a link and
> in
> conjunction inform upper layers to take care of the IP signaling over
> the new
> selected link.
>
> Example switch 3gpp2 to .11 interface and make the MIP signaling at
> layer 3
> perform MIP re-registartion with the new COA and old MIP address. So I
> am with you.
>
> The counter argument will be what if moblity is done at the Application
> layer?
> i.e. SIP mobility?
>
>
>
> Peretz Feder
>
>
>
> On 3/14/2005 5:12 PM, Greg Daley wrote:
>
>>Hi,
>>
>>Here's my question from today about
>>upper layer protocols.
>>
>>Have you considered if specifying direct
>>interfaces to upper-layers will cause confusion?
>>Wouldn't it be better to delegate this upper-layer
>>trigger function to L3?
>>
>>Greg
>