Training Videos from Cisco Systems

1. Introduction to Call Privilege Segmenting and describes the process for partitioning the Dial Plan and assigning calling search spaces to call-initiating entities using the Line/Device approach.
https://learningnetwork.cisco.com/docs/DOC-5446

There are two videos in this URL: https://learningnetwork.cisco.com/community/certifications/security_ccna
2. Site-to-Site VPNs: Cryptography Basics
3. Hardening Cisco IOS Devices