Resolving Apple TV 2 & 3 Home Sharing Issues

FWIW, I have found that when my ATV 3 will not wake up the Mac I use as my primary iTunes library server & I just get the spinner & 'loading' message on the TV, if I hold down the Menu button to return to the home screen, wait a few seconds, & then select Computers again, usually (but unfortunately not always) that wakes the Mac.

Stranger still, sometimes when I am certain the Mac is sleeping, everything works exactly as it should -- the Mac wakes up immediately after selecting the Computers app & there is essentially no delay at all, no spinner, no message, & the Library content is immediately available. This can happen even if the Mac was the last thing selected before the ATV went to sleep, & after waking it up with the Computer app still selected, the large area at the top of the screen where a few of the Library's items normally show up are still empty & all I see there is the Apple TV logo thing.

I have no idea why I get such different results at different times. It doesn't seem to have anything to do with how long the ATV or the Mac has been asleep, or if the last app selected on the ATV was the Computer one or something else. It may have something to do with having another of my Mac's awake & its iTunes app open when I try to wake the other one & but the 'no wake' behavior is so erratic that may just be coincidental.

For reference, I am using a 2008 vintage white MacBook running OSX 10.6.8 as my primary iTunes server & a 2 TB Time Capsule as my router. I also have a 2012 iMac running OSX 10.9.5 on the network with its own iTunes Library. Both Macs are connected to the Time Capsule via wired ethernet but the ATV is connected via WiFi, as is a third iMac.

It depends on how deep it sleeps and if it has still an IP address or not

Are you referring to the ATV or to the Mac?

If my MacBook was switching off its circuitry that supports "wake on network access," I could not wake it from my other Macs -- but I can do that, regardless of how long it has been sleeping, even if has been over two days since I last tried to wake it. This is true whether it or the Mac that is waking it is on WiFi or ethernet.

It works in all respects just like is described in About Wake on Demand and Bonjour Sleep Proxy -- except that sometimes it does not work when it is the ATV that is trying to wake it.

A little more about how wake on LAN ("WoL") works can be found at http://en.wikipedia.org/wiki/Wake-on-LAN#Principle_of_operation. Like it says, a network card or its equivalent that implements WoL operates in a low power state, listening for the 'magic packet' containing its MAC address, & sends a signal to the host computer's power supply or associated circuitry to wake the computer. The host computer's power supply just needs to supply the tiny amount of power needed to run the WoL circuitry, in the same way it does to power the circuitry that allows a USB device or built-in keyboard or power button to wake a sleeping host.

So in that respect the power supply in a Mac or PC that supports these features is never completely off unless it is completely disconnected from all sources of power. Otherwise, none of the circuits that wake it would get the power they need to do that.

Interceptor121 wrote:

Wake on demand works when implemented with magic packets so if you have a software that sends them the Mac will wake up

bonjour sleep proxy and wake on demand instead don't work and once the device has switched off the network card it never comes back

I don't understand what you mean by this. The low power part of the network interface (what I think you are calling the "network card"?) on my MacBook is not switching off -- if it was, then I could not wake the MacBook from my other Macs because there is no other way for them to reach it besides over the network. So I since can do that, that circuitry can't be switching off.

Also, I don't understand what you mean about getting a "real time clock wake" in response to an ATV wake signal. Like the term suggests, RTC wakes are triggered by the realtime clock in the Mac. They occur for example when users set up a time-of-day wake schedule in Energy Saver preferences, or (like the Apple article I mentioned earlier says) periodically to maintain active shared service registrations with the Bonjour Sleep Proxy. (On my MacBook that occurs every two hours or so.)

Maybe I'm missing something, but every source I can find suggests that the Bonjour "Wake on demand" (Sleep Proxy) is just a supplement to the WoL (or WoWLAN) standard that provides support for on-demand services (like iTunes, iPhoto, printer, & file sharing services) & it is still necessary for the proxy server to send a magic packet to the sleeping device to wake it up to share any of those services over the network.

Unfortunately, I can't see any of your images because the Jive software running ASC is acting up & failing to display image attachments to many posts, but from what I can tell from your descriptions, I am not seeing the same thing on my systems as you are on yours.

For one thing, I never get the message on the ATV that home (or family) sharing is off. For another, asleep or awake, all my Macs that have iTunes running always show up on the iOS Remote app "Devices" screen.

Because I'm using an Apple Time Capsule as my router & Apple's AirPort Utility to access its settings, I can only see the wireless clients it is currently connected to & not the wired ones, but when I switch my MacBook from ethernet to WiFi it shows up in Airport Utility & does not vanish when the MacBook is asleep.

Not to keep belaboring the point but there is no way for anything external to the Mac to trigger a real time clock event. The realtime clock built into a Mac is a separate subsystem very much like a digital alarm clock. It can be programmed to send a wake or sleep signal to the system based on its time of day info or on an elapsed time interval, but it can't respond to a network event.

Interceptor121 wrote:

That's exactly the point. The Apple Tv triggers the wrong event and therefore the iMac does not wake.

But an ATV or an iOS device cannot trigger a real time clock event. The only thing that can do that is the realtime clock itself. It has nothing to do with the software. The clock subsystem has a bidirectional data port for programming event times & informing the OS about those settings, the current time, & so on, but it has no way of communicating with the network ports or any of its associated circuitry. IOW, it can send a wake signal to the system but it can't receive or respond to them from any source.

I have done a little more research on this issue & one thing I noticed is that, according to Apple, for Wake on Demand to work reliably over WiFi the local wireless network must be the first one listed in the Preferred Networks list in the Advanced > WiFi tab of the Network System Preferences. If this isn't the way your Mac is set up, it might explain why we get such different results.

I also noticed that in System Profiler/Information in the Network section, either the "Buit-in Ethernet" or "Airport" line should display a "Sleep Proxies" section at the bottom with the network name of the sleep proxy it communicates with. (It should do this at least for Apple Airport base Stations or Time Capsules, but I'm not sure if it will list Apple TV's since I have a TC & that overrides an ATV as the sleep proxy server.) I think in any event it should show the network name of your wireless router/access point, so I would be interested in what, if anything, you see listed there on your Mac.