Re: [alto] ALTO Cost calendars in wireless access networks

Hi Xiao,

Thanks for your feedback and the pointers.

I have looked at I-D-pid-properties and possibly it can be used to build the solution (cell Id as a PID property). However, I am not clear about how PID properties can be used in queries, e.g. “what is the cost from PID with cellid=X to node Y”. Maybe this can be realized by first getting the (potentially large) PID map of the cells in the area, store it and then query the individual PIDs. But I have concern about the data volume. It may be better to have an extension to the query mechanism to consider a list of PID properties as filter in actual cost queries.

I agree that a push mechanism is beneficial in environments with dynamic content such as mobile.  I have to look deeper into the concrete SSE mechanism w.r.t. mobile, but here are some preliminary thoughts: One complication may be the design decision documented in section 7.1. In mobile, loss and re-establishment of connection is not unusual; just sending the whole map again on re-connect will not be efficient as it may happen too often. Also, SSE may have problems with some Web caching architectures as documented in RFC6202 section 3.2; it may be necessary to use long polling instead (which means we may run frequently into the issue documented in section 7.1).

Altogether it may be beneficial to define the method of ALTO incremental updates independent from the transport of the update. Then various PUSH methods such as SSE, long polling, webpush (http://datatracker.ietf.org/wg/webpush/charter/), even WebSockets can be used as a transport mechanism for server-initiated updates; and the method could even be used to optimize updates that are initiated by the client. And, as said above, for mobile a better handling of connection breakdown and re-establishment would be needed in order for this mechanism to really provide savings.

Kind regards,
Uwe

From: boxs.jq@gmail.com [mailto:boxs.jq@gmail.com] On Behalf Of ext Xiao SHI
Sent: Tuesday, November 11, 2014 8:38 PM
To: Rauschenbach, Uwe (NSN - DE/Munich)
Cc: ext RANDRIAMASY, SABINE (SABINE); IETF ALTO
Subject: Re: [alto] ALTO Cost calendars in wireless access networks

Hi Uwe,

Your document sounds like a very reasonable and useful extension. Just have two related thoughts:

1. Have you considered your cells extension using PID properties? The relevant draft is here: http://tools.ietf.org/html/draft-roome-alto-pid-properties-02#section-4.2 I believe the PID property document provides a solution to both requirements in your document (via Solution B).

2. Since the nodes change cells frequently, do you think this extension would benefit from incremental updates? The incr update document (http://datatracker.ietf.org/doc/draft-roome-alto-incr-update-sse/) provides the SSE framework, but I am not sure how convenient SSE is to mobile networks.

Best,
Xiao

On Tue, Nov 11, 2014 at 10:23 PM, Rauschenbach, Uwe (NSN - DE/Munich) <uwe.rauschenbach@nsn.com<mailto:uwe.rauschenbach@nsn.com>> wrote:
Hi Sabine,

Thanks for the pointer. Yes, I think your proposal will meet the expectations of the sketched use cases.
In fact, our proposal is orthogonal and tries to address the problem that in mobile networks, the network attachment
point can be one additional important parameter that should be addressed in ALTO.

So far, ALTO helps to decide “where to connect to” (where: the endpoint that provides the service).
The cost calendar enhances this to become “when and where to connect to”.
In mobile, the whole picture would become “via which cell/access, when and where to connect to”.

Kind regards,
Uwe

From: ext RANDRIAMASY, SABINE (SABINE) [mailto:sabine.randriamasy@alcatel-lucent.com<mailto:sabine.randriamasy@alcatel-lucent.com>]
Sent: Tuesday, November 11, 2014 8:36 AM
To: Rauschenbach, Uwe (NSN - DE/Munich)
Cc: IETF ALTO
Subject: ALTO Cost calendars in wireless access networks

Hi Uwe,

I see that your draft http://tools.ietf.org/id/draft-rauschenbach-alto-wireless-access-00.txt will be presented in the next ALTO WG session.

Given that your draft poses the need for a calendar in its following sections 3.2.1.  Cost calendar to extend battery life for background tasks and section 3.2.2.  Cost calendar to optimize application sessions, you may want to look at http://tools.ietf.org/id/draft-randriamasy-alto-cost-calendar-02.txt, that proposes ALTO cost calendars and will be presented during the ALTO WG session as well, as it would be interesting to see how this proposal may meet your expectations.

Best regards,
Sabine

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