How do I troubleshoot when my Direct Connect connection is DOWN and the TxRx optical signal receives no or low light readings?

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I want to troubleshoot my when my AWS Direct Connect is DOWN and the Tx/Rx optical signals receive no or low light readings.


To troubleshoot a DOWN Direct Connect connection that receives no or low light Tx/Rx optical signal readings, complete the following steps:

Check your ConnectionLightLevels and ConnectionState metrics

1.    Log in to your Amazon CloudWatch console and view your CloudWatch metrics.

2.    For Direct Connect dedicated connections, check the ConnectionLightLevelTx and ConnectionLightLevelRx metrics to determine the status of the light readings.

  • For 1/10gb connections, check for a good light signal within the range of -14.4 dBm and 2.50 dBm. Filter your Direct Connect data using the OpticalLaneNumber dimension.
  • For 100gb connections, check that the four ConnectionLightLevelTX readings and four ConnectionLightLevelRX readings are within a published light level range. For Tx light levels, the range is -4.3 to 4.5 dBm. For Rx light levels, the range is -10.6 to 4.5 dBm. If your light levels are not within these ranges, then see Troubleshooting layer 1 (physical) issues.

3.    Check if your Direct Connect ConnectionState metrics is indicating 1 for UP or 0 for DOWN.

Troubleshooting specific scenarios

Receiving -INF or out of the range for your Tx light signal

When you check your light levels through CloudWatch, you might receive -INF or out of range for your Tx signal. These responses indicate that the Tx signal isn't in an accepted range. For your Tx signal, the -INF or out of range indication is sent from AWS to your AWS router. Contact AWS Support for further assistance.

Receiving -INF or out of the range for your Rx light signal

To troubleshoot an -INF or out of range Rx signal, check for the following:

  • Check your AWS Health Dashboard for any planned maintenance or unplanned outages from AWS. Verify the same with your partner regarding their network.
  • Check if the cross connect is completed as per the LOA-CFA. If you have presence in the colocation, then contact your colocation provider to complete the cross connect. If you don't have presence in the colocation, then forward the downloaded LOA to your partner and request assistance in completing the cross connect.
  • Check your colocation equipment settings. Check that the speed is hardcoded to 1G or 10G and make sure full duplex set and auto-negotiation are turned off.
  • Check that you're using a single-mode SFP 1000BASE-LX (1310nm) for 1 gigabit ethernet, 10GBASE-LR (1310nm) for 10 gigabit ethernet, or 100GBASE-LR4 for 100 gigabit ethernet.
  • Check if your port comes UP when you manually perform a shut or no-shut on your device. Make sure you stop receiving a signal from your side after you shut the router interface at the colocation. Expect a delay when you perform a shut or no-shut.
  • Contact your colocation provider or partner for a media test. This includes patch-cords verification and cleaning, verifying cabling and signaling issues, and rolling the fibers or swapping Tx and Rx cables.
  • Contact the colocation provider and request a written report for the Tx/Rx optical signal across the cross connect as a reference.
  • Perform a loopback at the Meet-Me-Room (MMR) toward your router. If the port on the colocation equipment comes UP, then the MMR link is good. Check the Tx and Rx lights on your equipment.
  • Perform a loopback from the MMR towards the AWS router. Verify that the port comes UP through the Direct Connect portal.

If you're still having issues after completing the preceding steps, then contact AWS Support.

Related information

AWS Direct Connect Delivery Partners

AWS OFFICIALUpdated a year ago