Interesting. I wonder if Apple could address that NAT issue by sending the traffic from the opposite direction, essentially punching a hole in the NAT so that bi-directional communication could be established.
Frank -----Original Message----- From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Dan Brisson Sent: Wednesday, March 12, 2014 3:20 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Apple TV display mirroring spectrum use in HD wifi I can confirm that NAT does throw this for a loop. This morning I tried connecting my iPhone 5S that was behind a NAT device to an AppleTV on the other side. I could see the AppleTV in the AirPlay list, I could select it but then it wouldn't complete the mirroring. It would just default back to the "iPhone" option. I did a packet capture and found that the AppleTV was trying to open up a UDP stream to my iPhone, presumably for audio, and the NAT device was not letting the UDP packet in. Apparently if the UDP stream doesn't get established, the devices will just give up. -dan Dan Brisson Network Engineer University of Vermont (Ph) 802.656.8111 dbris...@uvm.edu On 3/12/14, 4:14 PM, Julian Y Koh wrote: > On Wed Mar 12 2014 15:11:34 CDT, Julian Y Koh <kohs...@northwestern.edu> wrote: >> I don't think that all AppleTV units have Bluetooth. I'm not exactly sure which revs do or don't offhand unfortunately. > Another thing is that I would imagine that both the iOS device and the AppleTV need to be able to reach each other directly using unicast. So if the AppleTV is behind a NAT device with respect to the iOS device, or if you have somehow blocked unicast traffic between clients on your wireless network, you might be able to do the discovery via Bluetooh but not actually stream any traffic. > > ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
