Wi-Fi Calling issues

    Learn how to troubleshoot Wi-Fi Calling problems. If you have an Android phone and you use the Wi-Fi Calling app, see Wi-Fi Calling troubleshooting for Android.

     

     

    Can't change call forwarding, call hold, or call waiting settings

    When you try to change the call forwarding or call waiting settings using Wi-Fi Calling, you may see on your screen, "Network or SIM card error." When you're actively using Wi-Fi Calling, the call forwarding and call waiting settings cannot be changed.

     

    To resolve this issue, simply change the settings when you're not using Wi-Fi Calling, You can also use short codes to change call forwarding and call waiting settings.

     

     

    Can't use call forwarding, call hold, or caller ID

    If you're using Wi-Fi Calling, and the other party is using Wi-Fi Calling as well, you may notice issues with receiving incoming calls and with incoming calls not forwarding to voicemail.

     

    To resolve this issue, visit the Phones page and select your device. Then, click the SOFTWARE UPDATE button and follow the steps to update to the latest version.

     

     

    REG02, REG05, REG06, REG99 errors

    This message displays when the SIM card has not received a needed SIM card update. This update is automatically sent from the network after a SIM card or phone number change has been completed.

     

    To resolve this issue, make you're in T-Mobile coverage and contact T-Mobile Customer Service. Customer Service can send the SIM card update to you.

     

     

    'REG01: Invalid certificate' error

    This message displays when your phone is having trouble connecting to the Wi-Fi Calling service.

     

    You might see alternate versions of this error, such as:

    • ER01
    • REG01
    • Invalid Cerificate

     

    To resolve this error, turn off Wi-Fi for 1 minute. Then, turn it back on and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps. If you still see the error, contact T-Mobile Customer Service.

     

     

    Can't make or receive Wi-Fi calls or call quality issues

    If you're experiencing dropped calls, have audio quality issues, or have trouble with Wi-Fi calls, it could be due to a Wi-Fi issue or a phone problem.

     

    To resolve this issue:

     

    1. Make sure of the following:
      • You have high-speed Internet service (DSL, cable, FiOS, public Wi-Fi)
      • You're connected to Wi-Fi and within 15 feet of the router
      • The wireless router is directly connected to the modem
      • The wireless router is on the latest firmware version
      • You're not near machines or appliances that can cause Wi-Fi interference, such as 2.4Ghz baby monitors, 2.4Ghz cordless, and Bluetooth-enabled devices
    2. Run a speed test at http://www.speedtest.net. If your download speed or upload speed aren't higher than .25 Mbps, the problem is with the Internet connection.
    3. Turn off your phone, router, and modem. If you're using public Wi-Fi, jump to step 6.
    4. Turn on your modem.
    5. Once the modem shows that it has established an Internet connection, turn on the router.
    6. Once the router indicates it has connected, turn on your phone handset and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps.
    7. If you are still having problems with Wi-Fi calls, contact T-Mobile Customer Service.

     

     

    Can't use text or picture messaging

    If you're experiencing messaging issues, it could be due to a Wi-Fi issue or a phone problem.

     

    To resolve this issue:

     

    1. Turn off your phone for 30 seconds.
    2. Turn it back on and try to use Wi-Fi Calling. Visit the Phones page, and select your device. Look for Wi-Fi Calling to access guided steps.
    3. Try to send a picture message to your own 11-digit mobile number while connected to Wi-Fi Calling.
    4. If you are still having problems with messaging, contact T-Mobile Customer Service.

     

     

    Error codes

    Wi-Fi calling errors display when there are problems connecting to Wi-Fi, or when there is a problem with the Wi-Fi Calling service.

     

    Scroll to the error for steps to fix the problem.

     

    ErrorPotential CausesAction

    ER02

    DNS Error

    • No WAN connection on the router
    • ISP is down (no internet)
    • DNS service is down
    • firewall is blocking DNS query
    • Wi-Fi network has captive portal and requires user to login or acknowledge terms and Conditions (public Wi-Fi)
    1. Confirm that you have been able to use this Wi-Fi network for Wi-Fi Calling
    2. Confirm that you can use the internet when connected to Wi-Fi by opening a browser and trying to open new webpages
    3. If Internet does not work, the router may need to be checked or power cycled to restore internet service
    4. If browsing over Wi-Fi works as expected, check to see if there is any firewall enabled
    5. Disabling/enabling Wi-Fi should be attempted
    6. If the issue persists, contact your internet service provider

    ER03

    DNS Error

    Same as ERO2Same as ER02

    ER04

    DNS Error

    Same as ER02Same as ER02

    ER041

    DNS Error

    Same as ERO2
    1. Enable/disable Wi-Fi Calling
    2. Power cycle the phone.
    3. Attempt to access the web on the phone over Wi-Fi
    4. If the error is not resolved, power cycle the router and modem.
    5. Attempt to access the web on the phone over Wi-Fi.
    6. If you have internet connectivity, walk through the steps to connect to Wi-Fi Calling.
    7. If the issue remains unresolved, contact us.

    ER05

    Invalid SIM

    SIM card

    To resolve this issue, contact us.

    ER06

    SIM not ready

    SIM card

    To resolve this issue, contact us.

    ER07

    Unable to Connect

    Wi-Fi Calling application error
    1. Enable/disable Wi-Fi Calling
    2. Power cycle the phone.
    3. Attempt to access the web on the phone over Wi-Fi
    4. If the error is not resolved, power cycle the router and modem.
    5. Attempt to access the web on the phone over Wi-Fi.
    6. If you have internet connectivity, walk through the steps to connect to Wi-Fi Calling.
    7. If the issue remains unresolved, contact us.

    ER081

    Unable to Connect

    No response from the network to the deviceSame as ER07

    ER082

    Unable to Connect

    Network response is corrupted or intermittentSame as ER07

    ER08

    Unable to Connect

    Most devices will show REG99: Unable to Connect.

     

    Error can appear in the following cases:

    • Firewall
    • Wi-Fi network requires user to log in or acknowledge terms and conditions (public Wi-Fi)
    1. Confirm that you can use the internet when connected to Wi-Fi.
    2. Open a browser.
    3. Open a new webpage.
    4. If Internet does not work, power cycle the router.
    5. Verify if a firewall is enabled.
    6. Disconnect and reconnect Wi-Fi

    ER010

    Invalid Certificate

    Most devices will show ER01: Invalid Certificate.

     

    Appears when mutual authentication between the device and the network fails.

     

    Typically a transient error that will fix itself.

    Intermittent Error

    1. No action is needed.
    2. The device will attempt to reconnect to fix the error condition.

     

    Persistent Error

    1. Enable/disable Wi-Fi Calling
    2. Power cycle the phone.
    3. Attempt to access the web on the phone over Wi-Fi
    4. If the error is not resolved, power cycle the router and modem.
    5. Attempt to access the web on the phone over Wi-Fi.
    6. If you have internet connectivity, walk through the steps to connect to Wi-Fi Calling.
    7. If the issue remains unresolved, contact us.

    ER101

    Invalid Certificate

    The certificate shared by network has invalid content.
    1. Enable/disable Wi-Fi Calling.
    2. If issue is not resolved, power cycle the device. This should take care of the error.

    ER011

    Invalid Certificate

    Most devices wil show ER01: Invalid Certificate.

     

    Certificate is expired or issue exists with certificate verification server.

    Same as ER010

    ER111

    Invalid Certificate

    The certificate shared by network has  invalid content.
    1. Enable/disable Wi-Fi Calling.
    2. If issue is not resolved, power cycle the device. This should take care of the error.

    REG90

    Unable to Connect

    Network rejects the registration attempt by the device.To resolve this issue, contact us.

    REG91

    Unable to

    Connect

    Network rejects the network registration attempt by the device.
    1. Disable/Enable Wi-Fi calling
    2. Power cycle the device
    3. Make sure to uninstall or disable any third party applications to connect to Wi-Fi
    4. Ensure that the device is on the most recent software version
    5. If the issue remains unresolved, contact us.

    REG09

    Missing 911 Address

    Network issue

    To resolve this issue, contact us.

    REG99

    Unable to

    Connect

    Devices that have not updated their error codes may show REG99 instead above errors.

    To resolve this issue, contact us.

     

     

    Signal issues

    Wi-Fi Calling signal troubleshooting

    1. If you are able to get signal, place a test call while not on Wi-Fi:
      • If the issue happens on normal calls, it is not a Wi-Fi issue.
    2. Verify that you are not currently using your device as a Mobile HotSpot.
    3. Turn on Wi-Fi Calling. See device how-tos for steps.
    4. Verify that your device software is up to date.
    5. For Android, set Wi-Fi Calling connection preference to Wi-Fi Preferred.
    6. Verify that your device is connected to Wi-Fi and you can access data.
    7. Restart your device.
    8. Make sure you are near the wireless router.
      Note: Wi-Fi signal quality will degrade as you move away from the router.
    9. If your device is showing a specific error code, see error codes.
    10. If the issue persists, ensure the router used for Wi-Fi calling is connected directly to the broadband modem and follow the appropriate steps below:

     

    Scenario/TypeAction
    Router is not directly connected to the modem (cascaded)

    You must plug the modem directly into the router, with no other routers or devices in between. This is required for network traffic to be directed correctly.

    Router is directly connected to the modem (not cascaded)
    • Use a computer connected to the router to perform a speed test and ensure you are getting sufficient speeds.
    • You can use a site such as internetfrog.com, or speedtest.net
    • If the speeds are not met, you will need to contact your ISP to troubleshoot your internet connection.
    • For @Home routers, change the RF channel used on the router. It must be set to either 1, 6, or 11. For steps, see Router Administration Page: Linksys WRTU54G-TM.
    • Note: Wi-Fi CellSpot Routers come pre-configured so step 3 is not required.
    • If other routers are present, ensure they are not using the same channel as the router used for Wi-Fi calling.
    • Verify other routers are placed at least 3 feet away from each other.
    • Disable any potential sources of 2.4Ghz RF interference such as baby monitors, microwaves, or cordless home phones.
    • Power off your modem first, then your router, and finally your phone, in that order.
    • Power the modem back on, and once it shows that it has established a connection, power on the router, then once the router is fully connected, power on the phone and retest.
    • If the issue persists, contact your ISP to verify the stability and speed of your network connection:
    • Advise the 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 and/or cannot handle VOIP traffic, you will need to work with them to get Wi-Fi Calling functioning.
    • They must allow DNS lookups through the firewall. These are IPv4 blocks registered only to T-Mobile.

       

      IPv4 Address BlockPortTCP/UDPDescription
      208.54.0.0/17500UDPIPsec - IKE : Authentication [WFC 2.0]
      4500UDPIPsec - NAT traversal : Encrypted voice traffic [WFC  2.0]
      5061TCP/UDPSIP/TLS : Encrypted SIP [WFC 1.0]
      66.94.0.0/19443TCPHTTPS : Used for handset authentication [WFC 1.0]
      993TCPIMAP/SSL : Visual Voicemail [WFC 1.0]
    • If ISP connection can handle VOIP traffic, and all the above troubleshooting has been performed, contact us.

     

     

     

    Related pages

     

    Wi-Fi Calling troubleshooting for Android