03-02-2021 08:55 AM
Hey guys I have a question about TDR results on my Cisco 3650 Switch.
It shows up that I have a wrong cabling connection with inverted pairs and another pair with short/crosstalk.
But the phoneds and desktops connected to it works normally except the last interface below which is g1/0/8 that restarts the phone regularly.
Can everyone confirme that I need a cabling correction or can keep this scenario. Or I really need to fix it and my phone will stop restarting.
Every response is welcome.
--------- ----- ---------- ------------------ ----------- --------------------
Interface Speed Local pair Pair length Remote pair Pair status
Gi1/0/12 100M
Pair A 0 +/- 1 meters Pair B Normal
Pair B 0 +/- 1 meters Pair A Normal
Pair C 32 +/- 1 meters N/A Short/Crosstalk
Pair D 32 +/- 1 meters N/A Short/Crosstalk
--------- ----- ---------- ------------------ ----------- --------------------
SWT0249#show cable-diagnostics tdr i g1/0/17
Gi1/0/17 100M
Pair A 0 +/- 1 meters Pair B Normal
Pair B 0 +/- 1 meters Pair A Normal
Pair C 21 +/- 1 meters N/A Short/Crosstalk
Pair D 21 +/- 1 meters N/A Short/Crosstalk
---------------------------------------------------
SWT0249#show cable-diagnostics tdr i g1/0/8
Gi1/0/8 100M
Pair A 0 +/- 1 meters Pair B Normal
Pair B 0 +/- 1 meters Pair A Normal
Pair C 35 +/- 1 meters N/A Short/Crosstalk
Pair D 35 +/- 1 meters N/A Short/Crosstalk
Solved! Go to Solution.
03-02-2021 10:48 AM
I would test the phone itself, move it to different port or -better -connect to switch directly to see if it keeps on rebooting. What is your phone model? At speed of 100M, Pair C and D are not used at all, So this is why your other phones are OK. You will need those 2 pairs for 1Gig.
I think that is normal results if your phone works at 100 only. I have seen this before , working fine like that.
You will need those 2 pairs for 1Gig.
Regards, ML
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03-02-2021 10:48 AM
I would test the phone itself, move it to different port or -better -connect to switch directly to see if it keeps on rebooting. What is your phone model? At speed of 100M, Pair C and D are not used at all, So this is why your other phones are OK. You will need those 2 pairs for 1Gig.
I think that is normal results if your phone works at 100 only. I have seen this before , working fine like that.
You will need those 2 pairs for 1Gig.
Regards, ML
**Please Rate All Helpful Responses **
03-02-2021 11:10 AM
Hey Martin, thanks.
I'm gonna change the port and phone because it's too old, we have several of this model 7912. Also will connect direclty.
best regards.
03-02-2021 10:50 AM
What firmware is the switch running on?
03-02-2021 11:02 AM
Hey Leo it's
03.07.05E
03-02-2021 11:27 AM
@ronicardosocruz wrote:
03.07.05E
I have used this exact IOS-XE version in the past and I know TDR "does not work".
The commands are accepted and they will spat out an output, however, the result cannot be accepted with confidence.
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