If you are using the WebEx client for phone calls, you will need to update you location for E911 Emergency Services to know you location when a 911 call is placed. 

Using the WebEx App, click on the E911 settings button in the lower left hand corner of the app.  A new window will pop up asking you to enter your location. Click save when you are finished. 

For more help, visit Webex App Help or submit a Helpdesk Ticket.