T-Mobile LineLink troubleshooting

Troubleshoot any issues after you complete LineLink setup.

 

 

Preliminary checks

Before troubleshooting, ensure the following:

  • Your account has the LineLink rate plan and a valid e911 address.
  • There is a landline phone plugged in to the T-Mobile LineLink Home Phone Adapter.
  • You have followed and completed the LineLink setup.
  • The Micro-SIM card is properly inserted and has not been swapped out with another SIM card.

 

 

No dial tone / flashing LEDs / did not complete setup

  1. If the T-Mobile LineLink Home Phone Adapter has a green blinking power LED, verify your e911 address.
  2. If your LineLink LEDs indicate working status and there is no dial tone, the issue is likely with your equipment. In this case, follow these steps:
    • Check the phone and LineLink cabling and setup.
    • Try a different RJ11 phone cable or phone set if possible.
  3. If LineLink has a flashing orange phone light, remove and reinsert your SIM card.
  4. Ensure that the middle cutout of the SIM card (Micro SIM) is used.
    • If the smallest cutout is used, push out the middle-size adapter before inserting the SIM card.
    • Make sure that the SIM card needs is inserted with the metal facing up and cut corner towards the device.
  5. When properly inserted, the SIM card will click in place.
    1. If the SIM card is improperly inserted, remove and reinsert it.
    2. If you can't remove an improperly inserted SIM car, go to a retail location for further assistance.
  6. Restart the device by disconnecting and reconnecting the power cable.
  7. Ensure that LineLink is using the most current firmware version.
  8. Run a speed test and confirm that your connection meets these minimum required speeds. Satellite Internet and cellular broadband are not supported for LineLink.
    • Download: 2 Mbps (or more)
    • Upload: 2 Mbps
    • Max Pause: Less than 10 ms
    • Quality of Service: 85%
  9. If the speed results aren't met, contact your ISP and explain/check:
    • You are using a VOIP service and need to check your connection.
    • The following ports have been opened:
      • 500 UDP
      • 4500 UDP
      • 5061 TCP/UDP
      • 443 TCP
      • 993 TCP
    • For business/corporate consumers, ensure the following IPv4 address blocks are whitelisted:
      • 208.54.0.0/17
      • 66.94.0.0/19
  10. Plug the LineLink device into a different LAN port on the back of the router.
  11. Restart the device and wait several minutes for the LineLink to provision.
  12. Power off LineLink, the router, and the modem.
  13. Power on the modem. When the modem has established an Internet connection, power on the router.
  14. When the router has connected, power on the LineLink and then retest.
  15. If the problem persists after you've completed these steps, contact us.

 

 

Post setup issues

  1. Verify the phone light on the device is either solid blue or flashing blue.
  2. Restart the device.
  3. If the LineLink LEDs indicate working status and a dial tone isn't present, the issue is likely with your equipment. In this case, follow these steps:
    • Check the phone and LineLink cabling and setup.
    • Try a different RJ11 phone cable or phone set if possible.
  4. If possible, try a different cordless or wired phone and check if the audio quality is poor.
    • If the audio quality improves, the original phone is the root cause of the issue and should be replaced.
  5. Ensure LineLink is using most current firmware version.
  6. Run a speed test and confirm that your connection meets these minimum required speeds. Satellite Internet and cellular broadband are not supported for LineLink.
    • Download: 2 Mbps (or more)
    • Upload: 2 Mbps
    • Max Pause: Less than 10 ms
    • Quality of Service: 85%
  7. Restart the LineLink device and the RJ11 handset, then wait several minutes for LineLink to provision.
  8. Ensure that other devices (e.g., baby monitor, another router) are not interfering with LineLink. For cordless phones, these devices can interfere with the phone’s connection. Corded phones don't interfere with LineLink.
  9. Power off LineLink, the router, and the modem.
  10. Power on the modem. When the modem has established an Internet connection, power on the router.
  11. When the router has connected, power on LineLink and then retest.
  12. If the issue persists, contact your ISP to verify the stability and speed of your network connection. Advise provider that you are attempting to use a VOIP service and need to verify that your connection is stable enough to handle voice traffic.
    • If your ISP has a technical issue or cannot handle VOIP traffic, work with your ISP to get Wi-Fi Calling functioning.
    • The ISP must allow DNS lookups through the firewall.These are IPv4 blocks registered only to T-Mobile. This simplifies the firewall configuration and allows T-Mobile to re-size the network without affecting your environment.
      • IPv4 208.54.0.0/17
        • Port 500, UDP, IPsec - IKE : Authentication [WFC 2.0]
        • Port 4500, UDP, IPsec - NAT traversal : Encrypted voice traffic [WFC  2.0]
        • Port 5061, TCP/UDP, SIP/TLS : Encrypted SIP [WFC 1.0]
      • IPv4 66.94.0.0/19
        • Port 443, TCP, HTTPS : Used for handset authentication [WFC 1.0]
        • Port 993, TCP, IMAP/SSL : Visual Voicemail [WFC 1.0]
  13. If the issue persists after all troubleshooting has been completed, contact us.