--- title: "Cisco 79XX - Troubleshooting Cisco 7942 Or 7962 VPN Phone" slug: "cisco-79xx-troubleshooting-cisco-7942-or-7962-vpn-phone" tags: ["calltower", "public"] updated: 2026-09-18T13:41:45Z published: 2026-09-18T13:41:45Z canonical: "learn.calltower.com/cisco-79xx-troubleshooting-cisco-7942-or-7962-vpn-phone" --- > ## Documentation Index > Fetch the complete documentation index at: https://learn.calltower.com/llms.txt > Use this file to discover all available pages before exploring further. # Cisco 79XX - Troubleshooting Cisco 7942 Or 7962 VPN Phone #### Goal The purpose of this article is to help users understand how to troubleshoot a Cisco 7942 or 7962 VPN enabled phone and educate on how these phones are configured and connect. ## CASE DISPOSITION: - Case Record Type: Support Standard - Department: Support - Type: Problem - Product: Cisco - SubProduct: Hardware - Issue: 79xx - Sub Issue: VPN - Other Issue: N/A - Priority: (This will depend on how many phones are affected) P3 - If One Phone. - Severity: High - Urgency: Depends on how many phones are affected. ## Resolution/Steps **Register the phone on a hosted voice connection** - The phone first needs to be registered on a hosted provided voice connection if this has not or cannot be done the phone may need to be sent to a site that has this connection or replaced. - Once the phone has registered on the voice connection, you may plug the phone into any normal data internet connection. **Verify VPN is enabled** 1. On the phone press the “Settings” button 2. Select “Security ” (option 4) 3. Select “VPN Configuration” (option 8) 4. Option 1 should be enabled 4.1 If option 1 is disabled select the “Enable” soft key at the bottom of the screen. **Clear the CTL and ITL Security Files** 1. On the phone press the “Settings” button 2. Select “Security Configuration” (option 4) 3. Select “Trust List” (option 5) 4. CTL file (option 1) should read “Not Installed” & ITL File (option 2) should read “Not Installed”. 5. If either of these shows anything other than “Not Installed”: 6. Press **# to unlock the settings 7. Select the file using the “Select” soft key 8. Press “Unlock” using the soft key 9. Press the “More” soft key 10. Select the “Erase” soft key **Verify the TFTP Settings on the Phone** 1. On the phone press the “Settings” button 2. Select the option “Network Configuration” (option 2) 3. Select “IPv4 Configuration” (option 1) 4. Scroll to “Alternate TFTP” (option 16) and it should read “Yes” 5. Scroll to the “TFTP Server 1” (option 17) and it should read “” 6. If the “Alternate TFTP” is set to “No” or “TFTP Server 1” is incorrect: 7. Press **# to unlock the settings 8. Highlight “Alternate TFTP” (option 16) 9. Press the soft key labeled “Yes” 10. Scroll to “TFTP Server 1” (option 17) 11. Press the soft key labeled “Edit” 12. In the new screen enter “” 13. Press the “Validate” soft key 14. Press the “Save” soft key 15. The phone may reset itself after these changes ## Additional Information/Troubleshooting Steps - If VPN authentication fails, press the “Retry” soft key (you may need to press this button multiple times). - If the phone still fails to connect after multiple times, unplug the phone so that it powers completely off, then plug it back in and try to connect again. **Contact Support** - If the problem persists, or TFTP server information is needed after multiple attempts contact the support team for further assistance by calling 800-347-5444 or emailing [support@calltower.com](mailto:support@calltower.com). You can also chat with CallTower Support by visiting calltower.com and selecting "LIVE CHAT" at the bottom right hand of the page. - Please provide the following information to the CallTower Support Technician: - MAC Address of the phone. - Name of the user of the phone. - This information will assist in arriving at a quicker resolution. ### Common Issues/Related Articles Factory Reset: - 7940 and 7960: [{{ glossary.UC}}.solutions/Cisco/002Phones/79XX_Series/Cisco_-_Phone%3A_7940_and_7960_Factory_Reset_Procedure">Cisco - Phone: 7940 and 7960 Factory Reset Procedure](/v1/docs/cisco-79xx-7940-and-7960-factory-reset-procedure) - 7920: [Cisco - Phone: 7920 Factory Reset Procedure](/v1/docs/cisco-79xx-factory-reset-procedure) - 7942 and 7962: Cisco - Phone: 7942 and 7962 Factory Reset Procedure - 7945, 7965, and 7975: [Cisco - Phone: 7945, 7965, 7975 Factory Reset Procedure](/v1/docs/cisco-79xx-7945-7965-7975-factory-reset-procedure) - 7921: [Cisco - Phone: 7921 Factory Reset Procedure](/v1/docs/cisco-79xx-7921-factory-reset-procedure) - 7925: [Cisco - Phone: 7925 Factory Reset Procedure](/v1/docs/cisco-79xx-7925-factory-reset-procedure) 79XX Features: - [Cisco - Phone: Overview - 79XX Series](/v1/docs/cisco-79xx-series-overview) - [Cisco - Phone: iDivert - 79XX Series](/v1/docs/cisco-79xx-idivert) - [Cisco - Phone: Pickup - 79XX Series](/v1/docs/cisco-79xx-call-pickup) - [Cisco - Phone: Extension Mobility - 79XX Series](/v1/docs/cisco-79xx-extension-mobility) - [Cisco - Phone: Joining Calls - 79XX Series](/v1/docs/cisco-79xx-joining-calls) - [Cisco - Phone: Receiving Calls - 79XX Series](/v1/docs/cisco-79xx-receiving-calls) - [Cisco - Phone: Call Park - 79XX Series](/v1/docs/cisco-79xx-call-park) - [Cisco - Phone: Speed Dials - 79XX Series](/v1/docs/cisco-79xx-speed-dials) - [Cisco - Phone: Transferring a Call - 79XX Series](/v1/docs/cisco-79xx-transferring-a-call) - [Cisco - Phone: Do Not Disturb (DND) - 79XX Series](/v1/docs/cisco-79xx-do-not-disturb) - [Cisco - Phone: Answering Additional Calls - 79XX Series](/v1/docs/cisco-79xx-answering-additional-calls) - [Cisco - Phone: Cisco Function Directories - 79XX Series](/v1/docs/cisco-79xx-function-directories) - [Cisco - Phone: Switching Between Calls - 79XX Series](/v1/docs/cisco-79xx-switching-between-calls) - [Cisco - Phone: Cisco Function Settings - 79XX Series](/v1/docs/cisco-79xx-function-settings) - [Cisco - Phone: Cisco Function Buttons - 79XX Series](/v1/docs/cisco-79xx-function-buttons) - [Cisco - Phone: Returning to Initial Call - 79XX Series](/v1/docs/cisco-79xx-returning-to-initial-call) - [Cisco - Phone: Placing a Call on Hold - 79XX Series](/v1/docs/cisco-79xx-placing-a-call-on-hold) - [Cisco - Phone: Call Forwarding an Incoming Call - 79XX Series](/v1/docs/cisco-79xx-call-forwarding-an-incoming-call) - [Cisco - Phone: Meet Me Conference Call - 79XX Series](/v1/docs/cisco-79xx-meet-me-conference-call) - [Cisco - Phone: Cisco Call Forwarding All - 79XX Series](/v1/docs/cisco-79xx-call-forwarding) - [Cisco - Phone: Placing a Call - Internal, External, 911 or 411 - 79XX Series](/v1/docs/cisco-79xx-placing-a-call)