CUCM secure by default, CTL, ITL, What does it all mean?

IMPORTANT FOR BLOG
https://supportforums.cisco.com/document/73611/ip-phone-security-and-ctl-certificate-trust-list

https://supportforums.cisco.com/document/73611/ip-phone-security-and-ctl-certificate-trust-list

https://supportforums.cisco.com/document/68701/communications-manager-security-default-and-itl-operation-and-troubleshooting


https://supportforums.cisco.com/document/60716/migrating-ip-phones-between-clusters-cucm-8-and-itl-files



http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-manager-callmanager/116232-technote-sbd-00.html

http://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-ip-phone-7900-series/113500-trust-list.html

http://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/117299-problemsolution-product-00.html

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/security/8_6_1/secugd/sec-861-cm/secuphne.html