Re: [mif] AD review of draft-ietf-mif-current-practices

[stefano faccin <[e-mail]>]

Hello all,
I have reviewed version 06 of the draft and I have a few comments.

Under section 3.1.3 on the BlackBerry, I would modify "Java applications" to
just "applications", since I believe we want to capture the most generic
case of BlackBerry, independently of the OS.

Under section 3.1.3 on the BlackBerry, it says "An application connecting to
the Internet, can use either the BlackBerry Internet Service or the Internet
gateway of the wireless server provider to manage connections". Can we
modify this to "... can use either the BlackBerry Internet Service or the
Internet gateway of the wireless server provider or direct Internet
connectivity over WLAN to ..." for correctness/completeness?

In section 3.1.7 there is an incorrect statement "The RIM Blackberry behaves
differently, the connection manager selects the first SSID on which it has
managed to attach in the past." Please replace this statement with
"The RIM Blackberry
behaves differently: the user (e.g. the enterprise owning the device) is
allowed to define its preferred access. The connection manager selects
the first
SSID of the preferred list of SSIDs configured in the device and that is
available based on the WLAN scan the device has performed", since it is not
true that the BlackBerry always tries first the last SSID it has managed to
attach in the past.

The section also contain a statement that does not apply to all devices,
i.e. "When the IP stack fails to obtain an IP address, the handset, excepted
the iPhone, restarts WLAN attachment selecting the second SSID in the
list."The BlackBerry, when it fails to obtain an IP address after
successful WLAN
attachment, performs a new WLAN scan and, among the networks available, it
selects the next SSID in the preferred list, which means that the approach
is different from the one the original sentence tries to capture.

Cheers,

Stefano

On Tue, Feb 1, 2011 at 6:41 AM, <[e-mail]> wrote:

> Hello Jari,
>
> I've submitted a new version of draft-ietf-mif-current-practices (
> http://www.ietf.org/internet-drafts/draft-ietf-mif-current-practices-06.txt).
> According to your comments, Nokia (thanks again Teemu), Androïd and Linux
> sections have been updated with information regarding DNS configuration,
> RFC3484 support, RFC1122 status and address overlapping issue. Section
> "Apple" has been removed.
>
> BR,
> Pierrick
>
> > -----Message d'origine-----
> > De : SEITE Pierrick RD-RESA-REN
> > Envoyé : samedi 23 octobre 2010 12:01
> > À : [e-mail]; [e-mail]
> > Objet : RE: [mif] AD review of draft-ietf-mif-current-practices
> >
> > Hi Jari, all,
> >
> > We've submitted a new version of the draft-ietf-mif-current-practices
> > (More details inline). However, there is a pending issue: we still need
> > additional information, especially from manufacturers, to address your
> > concern with section 3.1.
> >
> > So, we request the support from the WG, especially from folks who have
> > provided per-OS initial information, to address Jari's concerns.
> Interface
> > selection is, generally, well documented but we need more details on
> > following topics:
> >
> > - Address selection: is RFC 3484 supported? Linux and windows implement
> > RFC3484 (I've just noticed that only the windows section refers to
> RFC3484,
> > I'll align the linux section in the next version), but what about the
> > others (nokia, blackberry, windows mobile, android)?
> >
> > - DNS resolution issues: Windows and Linux section are well documented.
> > But others sections must be developed. Reflecting Jari's comment: is DNS
> > configuration per-node or per-interface? If an application is bound to an
> > interface, does it always use the DNS settings for exactly that interface
> > or the per-node settings.
> >
> > - address space overlapping: we do not have information on these issues
> > and we'd appreciate feedback from the WG (especially from manufacturers
> > involved in MIF). When the terminal is simultaneously attached to several
> > interfaces, is the OS manage address space overlapping? If yes, how does
> > it work?
> >
> >
> > - The section "Apple Mac OS X" is poor in comparison to windows and Linux
> > section. If we do not have more information for apple mac os, we'll
> remove
> > the section.
> >
> > - Android: can we consider that basic android kernel (excluding vendors
> > specific implementations) manages multiple interfaces issues in the same
> > way than the current Linux OS?
> >
> >
> > Regards,
> > Pierrick
> >
> > > -----Message d'origine-----
> > > De : [e-mail] [mailto:[e-mail]] De la part de
> > Jari
> > > Arkko
> > > Envoyé : vendredi 1 octobre 2010 20:45
> > > À : mif; [e-mail]
> > > Objet : [mif] AD review of draft-ietf-mif-current-practices
> > >
> > > I have reviewed this document. Overall, this is a good document, but
> > > some work still remains. My biggest issues were the following:
> > >
> > > The document is quite focused on the access network selection problem,
> > > which has already been discussed extensively in RFC 5113. It is fine to
> > > include discussion of the access network selection problem as well,
> > > because it is all part of the same problem space. But I would have
> > > expected the document discuss in more detail what the various
> > > implementations do at layer 3. For instance, do they use RFC 3484, are
> > > DNS settings per-node or per-interface, if an application is bound to
> an
> > > interface does it always use the DNS settings for exactly that
> interface
> > > or the per-node settings, what happens with overlapping address space,
> > etc.
> > >
> > > The document is somewhat imbalanced, there's very little (too little)
> > > information about some devices and operating systems whereas the
> Windows
> > > description is detailed and informative. I would suggest that some of
> > > the devices for which there is very little information are either
> > > removed from the document or some more information is inserted about
> > them.
> > >
> > > Detailed comments:
> > >
> > > Section 3.1.3 s/in a MIF context/here/ (the MIF context is a fine term
> > > to use in WG discussion, but will look odd in a published RFC by the
> > > time the WG has concluded).
> > >
> >
> > NEW TEXT:
> >
> > In comparison to Windows Mobile 2003 SE, Windows phone 7 brings update of
> > the routing functionality in the case where the terminal can be attached
> > simultaneously to several interfaces.
> >
> > > On Section 3.1.4 (BlackBerry) it was unclear to me what type of
> gateways
> > > the text refers to. Default router, web proxy, application proxy,
> > > something else?
> >
> > I agree that the original text was unclear. I've revised the section but
> > Giyeong, please check we kept ideas from your original text.
> >
> > On the second paragraph of the same section it is
> > > unclear what "device" refers to. The entire device can use multiple
> > > networks simultaneously? Does that mean that one application can use
> > > multiple networks simultaneously, to the same destinations (like in
> > > mp-tcp) or to different destinations? Or just that multiple
> applications
> > > can use different networks simultaneously?`Please be more precise about
> > > what is actually happening, as opposed to claiming a general
> capability.
> > >
> >
> > Ok, text has been revised.
> >
> > > Section 3.1.7 says very little about the hard issues around MIF, such
> as
> > > whether overlapping address space is tolerated, whether there is a
> > > possibility of some policy being sent from the network, whether DNS
> info
> > > is per node or per interface, etc.
> > >
> > > But also other sections under 3.1 seem thin. I realize that its hard to
> > > get information, but at least some of these devices are open source and
> > > run on top of standard kernels such as Linux, so it should be possible
> > > to find out a bit more.
> >
> > I guess you are referencing to android terminals; I was also thinking
> that
> > the behaviour of an android could be deduced from current Linux
> > functionalities but it seems that the situation is more complex. It's
> true
> > that Android is based on a Linux kernel but some functions are sometimes
> > customized by vendors. So we sometimes experience different behaviour
> > between different android terminals. For instance, some android terminal
> > cannot run IPv6 only, they need getting an IPv4 address first, and then,
> > even with IPv6 support some android cannot manage multiple IPv6 prefixes
> > on a single interface; some others inhibit the 3G/WLAN multihoming....
> > while all these functions are well supported on a Linux laptop. Note that
> > it is not just a matter of configuration since and the only way to
> > overcome these limitations is to change the android platform.
> >
> > I've added in the text that behaviour of an android terminal can depends
> > on the vendors implementation.
> >
> > Or we can ask for further information from the
> > > people who gave us the original data, I suppose at least some of them
> > > work for the manufacturers.
> > >
> >
> > Yep, we need additional information from vendors....
> >
> > > > iPhone
> > > >
> > > > Iphone
> > > Inconsistent capitalization.
> > >
> >
> > Fixed
> >
> > > >       Whatever is the handset, fallback on L3 attachment failure is
> > not
> > > >       supported for motionless terminals.  Actually, the connection
> > > >       manager always selects the most powerful signal strength
> without
> > > >       considering IP configuration results.  In other words, if the
> > > >       terminal is unable to set up the IP connectivity on one wifi
> > > >       access, the connection manager will not try to attach to an
> > > >       alternative point of attachment (or SSID) as long as the signal
> > > >       strength of the first radio link is the most powerful.
> > >
> > > What is "motionless terminal"? All devices that you mention are mobile.
> > >
> >
> > We meant: a terminal which remains under coverage of the same AP.
> >
> > The test has been revised.
> >
> > > Besides, I'm fairly certain that the above does not apply to Android.
> > > The device that I have does seem to switch away from a strong-signal
> > > SSID to another SSID, if L3 attachment fails.
> > >
> >
> > Actually, we can have different behaviour with different Android
> platforms
> > (see above). The text in the doc applies only to the "HTC majic".
> >
> > > > in the scope of MIF.
> > > >
> > >
> > > ... in the scope of this document.
> > >
> >
> > Ok, fixed
> >
> > > Jari
> > >
> > > _______________________________________________
> > > mif mailing list
> > > [e-mail]
> > > https://www.ietf.org/mailman/listinfo/mif
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-- 
Stefano M. Faccin
==================
May the Force be with you