By default, Jabber will use your webcam when you place or receive a call if one is available. Here is how to change the setting to start calls without video:

MAC:

# Direction Screenshot
1 Click Jabber in the finder bar located in the upper left corner of the screen. Then click Preferences... from the drop down menu.
2 Click Calls along the top of the "Calls Preferences" screen. Then uncheck the box for "Always start my calls with video". Click the red circle in the upper left corner of the window.


PC:

# Direction Screenshot
1 Click your profile icon in the upper left corner of the Jabber window. Then click Settings.
2 Click Calls along the left side of the "Settings" window. Then check the radio button next to "Never start calls with video" if it is not already selected. Lastly, click OK near the bottom of the window.