Ethernet packets

[Schmark]

Cabling between IP cameras and NVR is Ethernet 8 wires. Commands go from NVR to Camera and data goes from Cameras to NVR, supposedly on different wires.

Is there a link showing the content of the command and data packets that are traveling on the cable? For example, are Main stream and Sub stream sent concurrently to the NVR on the same wire?

Thanks

-S

 

[fenderman]

Cabling between IP cameras and NVR is Ethernet 8 wires. Commands go from NVR to Camera and data goes from Cameras to NVR, supposedly on different wires.

Is there a link showing the content of the command and data packets that are traveling on the cable? For example, are Main stream and Sub stream sent concurrently to the NVR on the same wire?

Thanks

-S

That is incorrect. All data is passed on the same wires.

 

[Schmark]

Fenderman, are you saying data AND commands transit on the same wire? Is there some document/link describing what passes where?

-S

 

[fenderman]

Fenderman, are you saying data AND commands transit on the same wire? Is there some document/link describing what passes where?

-S

Yes, commands are data. These are ip cameras, everything is data.
If you want to know which wires see the pinout section at the very bottom
Power over Ethernet - Wikipedia

 

[Schmark]

Fenderman, I wired my system with T568B. Would you know which mode (see below) is used by the Hik cameras/NVR?

 

[fenderman]

Fenderman, I wired my system with T568B. Would you know which mode (see below) is used by the Hik cameras/NVR?

View attachment 42924

Most likely Mode A. In general standard poe switches will use mode A and midspans will use Mode B. There is an easy way to test - just cut the pin 4,5/7,8 cables and see if it works

 

[fenderman]

See corrected post. Most switches will use mode A - only using 2 pair/4wires.

 

[Schmark]

Mode B makes sense as it shows Tx and Rx on the same wire pairs. To go one step further, is there documentation showing packet content? I am interested how command, Main stream, and Sub stream are interleaved (and marked).

 

[fenderman]

Mode B makes sense as it shows Tx and Rx on the same wire pairs. To go one step further, is there documentation showing packet content? I am interested how command, Main stream, and Sub stream are interleaved (and marked).

You would have to use wireshark, it is using the 10/100 modes not gigabit. The cameras are not gigabit.