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On Friday 12 February 2010 11:42:26 Graham Murray wrote: |
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> Alan McKinnon <alan.mckinnon@×××××.com> writes: |
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> > On Friday 12 February 2010 09:44:01 Graham Murray wrote: |
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> >> Volker Armin Hemmann <volkerarmin@××××××××××.com> writes: |
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> >> > so how do you propose that a network connection manager tells a |
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> >> > broweser or mail app that they are offline? |
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> >> |
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> >> Why does the app need to know? Browsers normally have an online/offline |
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> >> menu selection and if you try to browse to a site when your network is |
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> >> offline then the browser will generate the appropriate error message. In |
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> >> any case, these notifications are only really of use on a single-homed |
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> >> non LAN connected system. On an office LAN, you may well be able to |
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> >> still access your mail server but a problem means that you cannot access |
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> >> any web sites. |
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> > |
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> > A network connection manager tells apps when the machine's interface goes |
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> > down, not when the gateway is no longer available. |
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> > |
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> > You have these two things conflated. |
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> |
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> Which still does not explain why the applications need to know when a |
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> network interface goes down but does not need to know when (for example) |
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> the ADSL connection (via an external router) to the 'outside world' goes |
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> down[1]. As far as both the application and the user are concerned the |
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> effect is exactly the same in both cases - the application is |
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> offline. If it is considered important to inform the application of one, |
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> then it should be equally important to inform the application of the |
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> other. If a network interface goes offline then the user needs to know, |
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> so as to take corrective action, but I do not think that telling the web |
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> browser and mail applications is the correct way of informing the user. |
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> |
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> [1] Which in my experience, while not a frequent occurrence, happens |
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> far more frequently than the network interface going down. |
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|
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The network beyond the machine is completely outside the control of any app on |
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the machine, that's why it is not checked for. Besides, if the gateway is |
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down, the LAN is usually still up local things are probably accessible. |
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|
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The most common case of the interface going down is the wireless kill switch |
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pressed or the LAN cable pulled out. That's something the user would like to |
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know due to many of them doing it a LOT. The system can send out a notify for |
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that, which apps can chose to listen to or not. The most common case would be |
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a popup saying "A cable is unplugged". |
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Mailers can then take themselves offline if they wish, and that ability |
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depends on what the dev decided to support. Just because you don't personally |
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see the point does not mean |
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|
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a. It is pointless, or |
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b. The message bus should not support such things |
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|
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-- |
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alan dot mckinnon at gmail dot com |