Which of the following statements accurately describe 802.11i? (Select all that apply.) a. WPA2 permits an attacker to remove devices from the network and impersonate them. b. WPA2 uses AES encryption to encrypt payload traffic. c. WPA was needed to replace the awful, compromised, obsolete WEP. d. Multiple keys are changed frequently to prevent them from being compromised. Which of the following are functions of an SBC? (Select all that apply.) a. Stateful management of SIP sessions by MITM control of packets. b. Registration proxy enabling VoIP devices to function on non-routable IP addresses. c. Records voice conversations from internal users and replays them to external users to bypass firewalls. d. Manage NAT entries for each VoIP device within a network