I recently purchased a new Apple TimeCapsule. I am a huge fan of Apple routers and how they work great with Apple and other network devices. The new device has been working well, but I did notice that my iPhone and iPad would not see all AirPlay devices at times. The only resolution was to turn Wifi off and back on again. This would be a temporary fix. Others in my family confirmed the same issue. :( Last night, my daughter needed to print a photo from her Mac to our wireless printer for a book report. Her Mac would not print, getting can't connect to printer type errors. I checked the printer and it said it had a valid IP and was happy on the wireless network. I noticed that my Mac had the same issue. I also noticed that both Macs couldn't see the printer. In addition, the AirPort Utility software on my Mac reported that it had the printer connected.
Last week, I happen to run across this osxdaily.com article which details using OS X's wifi diagnostics to determine the best 2.4GHz and 5GHz channels for your router. Well, I had left these settings set to "automatic" on my Time Capsule. On a whim, I decided to give this a go. Following the directions, the tools indicated 4 channels which would work best. I picked the first one reported for 2.4GHz and 5GHz and set the channels in the AirAport Utility software.
A day later, my devices continue to see all of my AirPlay devices and all Macs can easily print to the wireless printer. I assume that Apple's automatic channel settings in the Time Capsule didn't really find the best channels. As a result, I must have had enough interference to cause issues with Bonjour and AirPlay related services. Based on this, I will be periodically using the Apple wifi diagnostic tools to find the best channel and update my Time Capsule settings as necessary.