"Challenged: true/false" in Registration cache

Hi Folks,

 

When we print the registration cache of a specific user, we can see "Challenged: false/true" parameter. What is interpritted with this?

 

User: sip:3003@192.168.10.10  

Registered at: 2012-06-18-05:42:45     Surrogate User: false
Contact Information:    

Contact:      

Name: sip:3003@192.168.10.10      

Valid: true Challenged: false      

Registered at: 2012-06-18-05:42:45      

Last Registered at: 2012-06-18-06:00:21      

Expire: 2523      

Local expire: 39      

Half: 723

 

Cheers!

Manoj