Streaming: usb vs wifi

I was reading with increasing confusion until I hit question2.

Cat5 is ethernet cable not USB.. your title and every use of USB should be read as ethernet. USB cannot be used this way for networking.

Ethernet cabling is the BEST. Far superior to wifi.

So to answer questions.

Q1, yes swapping out the current AppleTV for new one is fine and will give you full bandwidth up to the limit of Comcast link unless you have gigabit. AE is limited wan to lan routing to about 300-400Mbps for most models. Less for older one.

Q2, Cat5 was sold over a very long period. Early stuff might not be gigabit compatible but later Cat5e certainly is. Just check your link speed and throughput that you have attained gigabit. If so no replacement is needed.

Even if it fails and you are only getting 100Mbit the issue might be cable termination so talk to us. You don't need more than about 30Mbps for 4K for a service like Netflix.. so it should still be fine.

Was the cable professionally installed in the wall? If so no problem..

If this is a 20M (60') patch cable taped to the floor maybe you need to replace.

Q3, Phasing that your EE friend is talking about is normally analogue audio not digital.. or you might have confused his explanation of correct pairing. Digital connections are great in not being concerned with such matters. It works or doesn't work. As stated in Q2, if you get gigabit you are fine.

It is only if the connection is slow you need to look deeper into the issue.

To test if you have gigabit check your speed to internet via ookla site. If your Comcast is say 200Mbps then you will immediately know it is working because you will achieve close to that. Only gigabit cabling could exceed 100Mbps. If your internet connection is slower than 100Mbps it is really going to make little difference as long as the cable is reaching 100Mbps.. again the test might show you.. 95Mbps for example means it is working well enough.

First, it appears that there is some confusion about "usb" and "Ethernet" here.

The comcast feed come to my office and is usb connected to an old airport extreme router.

No, it is not. It is connected via Ethernet from the Comcast modem/router to the AirPort Extreme. The USB port on an AirPort Extreme will only support a printer or a hard drive.

That in turn is hardwire via usb to another airport extreme at the other end of my house

No, it is not. An Ethernet cable connects the two AirPort Extremes together. As we noted above, the USB port(s) on the AirPorts will only support an attached printer or hard drive.

and that extreme is usb hardwired to my current apple tv box.

No, it is not. Same reason as above, plus the Apple TV does not have a USB port.

Question 1: would just swapping out the apple tv box for a new one give me the best possible 4K?

Yes, assuming that you have a 4K source and a 4K capable television.

question 2: If I stay with the hardwired approach should I swap out the existing cat5 cable for one with higher throughput as someone recommended?

No need to do this if your CAT5 cable is really CAT5e. It almost surely is unless the cable was installed 10+ years ago. It won't hurt to install CAT6 or higher cable if you want to "future proof" things for the next 20 years, but it won't help for the near future.

question 3: A EE friend says that I need to check on the "phasing" (or something like that) of my cable connection. Is that necessary?

I'm sure your friend means well, but he's in way over his head unless he really meant to say that the Ethernet cable needs to be wired correctly.

CMG" "TIA-EIA-568-B"

This is just the wiring standard. Short patch cables are seldom going to be problems unless it is faulty with broken wire or something.

The long run is cat6

That is great. Patch cables are easily and cheaply replaced. As long as the long run is done Cat6 and tested to gigabit it should be fine.. and might manage 10Gbit in future when prices come down.

Looks good. It would not hurt to use a CAT6 cable from the AE to ATV if the 5e cable has some years on it, but no rush needed on that.