Hardware TDR Ethernet cable diagnostics
Starting with KeeneticOS version 3.7, the TDR hardware diagnostics of Ethernet cables are available. This feature is generally not available on all network ports, only on those where it is feasible. For example, in the Giant (KN-2610) and Peak (KN-2710) models, this diagnostics works on the built-in 8-port RTL8370 series switch (it is supported on LAN ports and does not work on the blue WAN port, but if a LAN port is configured as a WAN port, diagnostics will also be supported on that port).
TDR (Time Domain Reflectometer) — a tool for detecting faults in cable lines using the locator (reflectometry) method. The TDR test helps identify the nature of the problem and the approximate distance to a twisted-pair Ethernet cable.
In the router's web interface, go to the Diagnostics menu, select a port on the Cable Diagnostics tab, and click the Test button. The Pulse Reflectometry Diagnostic Test (TDR) results for the selected interface will be displayed below.
Test statuses:
Normal — The pair is connected, and no problems are detected;
Not Connected — No contact with the terminal device. This may indicate an unconnected cable, a faulty or low-speed port on the terminal device, or a break in the pair's conductors;
Shorted — The twisted-pair wires are short-circuited;
Impedance mismatch — Possible causes of impedance mismatch are: twisted pair not properly crimped (reversed conductors); damaged pair conductors; defective connector at the end of cable;
No signal — The other end of the pair is connected to the port with the power off. This usually means that there is no problem with the pair itself;
Distance — The distance to the fault in metres. If no problems are found in the pair, this value is
0.
The twisted pairs A, B, C, D is equivalent to 1, 2, 3, 4:
Important
Please note the following points:
— When the terminal device connected to the router is in an active state (port powered and working), and the test status is displayed as Normal, then no cable distance will be determined. To determine the distance (cable length), you need to, for example, pull the cable out of the terminal device port, simulating a cable break and run the test again.
— Cable diagnostics is also supported on aggregated ports.
— When diagnosing one port, communication with the terminal devices is not interrupted on the other ports.