Re: HDMI with Ethernet?
Eh... Can I get a bit of clarification on what you are asking? Have you found cable that has a HDMI hookup on one end and has an ethernet connection on the other? If you have found such a cable, can you provide a link for such a cable? I am... intrigued.
Based on what you are saying and you found, I suspect you found a cable that claims to meet the relatively new 1.4 HDMI standard. Keep in mind one of the goals of HDMI: to provide an interface for which one cable can meet all needs thus making home theater systems simple so only one cable needs to be used for all hookups in between devices. Compare this to how things used to be done (and still are done in some cases). If you have a TV and wanted to connect it to a sound system, depending on whether you had just a stereo setup or a 5.1, you just about needed a seperate cable for each sound channel in most cases. So, just for this scenerio you could possibly need 5 or so cables. Imagine if had this setup and added a nice DVD player to it, one that supported 5.1. You would need 5 or so cables for that as well. Now you've upped your total cable count to 10. OUCH!! What a mess. With HDMI, you run one HDMI cable from the TV to the sound system, and then one cable from the DVD player to the sound system for a total of 2 cables. Much better and cleaner. There were times with some nice systems when you could just run one optical in the past, but those weren't common. Again, with HDMI, regardless of the setup you just run more than one cable.
Prior to HDMI 1.4, HDMI cables could carry all video and sound depending on the HDMI level. Plus, with HDMI 1.3a, there was some basic control added to the HDMI spec: when I turn on my TV as an example, the TV turns on the sound system. When I adjust the sound on my TV, the TV passes the command to the sound system and the sound system adjusts the sound volume. When I turn off the TV, the TV sends a command to my sound system so it will turn itself off. There isn't much in the HDMI spec [yet!], but it is there and I hope it gets better.
Anyway, with HDMI 1.4, the ability to pass through Ethernet singaling was added. Basically, you hook up an Ethernet enabled device, such as your TV, to an Ethernet cable which gives you access to the network and presumably the Internet. If all the other devices are HDMI 1.4 compliant and are hooked up to the TV with HDMI, assuming they can access Ethernet data (such as get on the Internet), they can access the Ethernet data over the HDMI cables as the Ethernet data is passed through the originating device, the TV in this scenerio, and goes to the receiving, all through the same HDMI cable.
Again, what I believe you are looking at is an HDMI cable and the cable is saying that it is good enough to carry Ethernet data at the same time it is transmitting video and sound.
I have a 1.3a HDMI setup myself so I haven't used this. I think one common scenerio deals with devices that may get on the 'net to get firmware while some devices can access the internet to retrieve streaming video, such as netflix. Imagine having an all 1.4 HDMI setup where everything is hooked up to a sound system using HDMI cables. Imagine your blu-ray allows you to access Ethernet so you can stream Netflix over the 'net so an Ethernet cable is hooked up to the player. Well, since the blu-ray is hooked up to Ethernet then all devices can access Ethernet due to the fact they are all hooked up via HDMI cables. Need a firmware update for the TV? The TV can access the Internet over the HDMI cables, due to the fact an ethernet cable is hooked up to the blu-ray, and retrieve its updated firmware.
I'm sure I have a detail or two above wrong as I don't claim to be an expert (although I do know a fair amount...) on this subject. However, I have the main point right: the ability to pass Ethernet data over the same HDMI cable at the same time with video and sound data is now possible and I suspect that's whatever you are looking at is trying to tell you.
Hope that helps.