How do I configure my Cisco 7940/7960 for SIP service?

VoIP Phones

How do I configure my Cisco 7940/7960 for SIP service?

How to check if your firmware is up to date and ready for SIP configuration

Before you're even able to configure your SIP settings, you need to check your firmware version is up to date! To get to this window:

  • Press the Settings key. The Settings menu is displayed.
  • Highlight Status.
  • Press the Select soft key. The Setting Status menu is displayed.
  • Highlight Firmware Versions.
  • Press the Select soft key. The Firmware Versions panel is displayed.

To be able to configure your phone, you need to look for P0S3, followed by xx-y-zz where x represents the major version, y represents the minor version, and z represents the subversions. e.g. P0S3-8-12-00

If your firmware starts with P0S3, you're good to go!


Unlock Configuration Mode

You need to unlock configuration mode to be able to make any changes! You’ll notice that there is a padlock symbol in the upper right hand corner of your LCD screen , which means the network configuration settings are locked. So how do you unlock it?

  • Press the Settings key. The Settings menu is displayed.
  • Scroll down to number 9: Unlock Configuration and press Select
  • Enter cisco - the default password, all lowercase - and press Accept

The network configuration menu should be displayed, and the lock symbol in the corner of your screen should now be unlocked!

Erase Locally Defined SIP Settings

Before you start configuring your phone with your settings, you need to erase any settings that may already be in the phone.

  • You should still be in settings after unlocking configuration mode. If you exited you need to unlock it again.
  • In the Settings menu highlight 4: SIP Configuration.
  • Press Select. The SIP Configuration settings are displayed.
  • Select 1: Line 1 Settings
  • Highlight the parameter for which you wish to erase the setting. In this case, each one - follow the following steps one-by-one for each line - 1: Name through to 7: Proxy Port
  • Press the Edit soft key.
  • Press the << soft key to delete the current value.
  • Press Validate to save and exit the Edit panel.
  • Press Back to exit the Line Configuration panel.
  • Press Save.

The phone will reset with the new information. Now you can enter your own settings!

SIP Configuration

Next we need to edit the SIP configuration to define your details. Here‘s a step by step guide through this part - make sure you double and triple check everything before saving to save yourself hassle!

  • Scroll up using using the navigation arrows to 4: SIP configuration and press Select
  • Select 1: Line 1 Settings
  • In the Line 1 configuration screen enter the following details (case sensitive):
    • Name: [your SIP username]
    • Shortname: [your SIP username]
    • Authentication Name: [your SIP username]
    • Authentication Password: [your SIP password]
    • Display Name: [optional]
    • Proxy Address:
    • Proxy Port: 5060
  • Once you have entered all of your details correctly press save, and then back.

Register with Proxy and NAT Setup

  • In the SIP Configuration Screen, scroll down to 7: Message URI using the navigation arrows and change this to *98
  • Scroll down to 10: Register With Proxy and change this to YES
  • Scroll down to 24: NAT enabled and change this to YES
  • Press Save to apply changes!

Final step - make sure call encryption is turned off for the user registered to the phone! Go to User > Edit > Call Encryption > Disable.

Now reboot your phone (simply unplug the power cable for 5 seconds and plug it in again) and your phone should now register with!

If you‘re still having trouble, double check all the information you‘ve entered is correct and reboot again.


If you need any further help today, please don't hesitate to contact our friendly support team on 0330 122 6000 or by email!

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