Which two statements describe characteristics of Cisco Unified Border Element high availability,
prior to Cisco IOS release 15.2.3T, using a box-to-box redundancy configuration? (Choose two.)

A.
It leverages HSRP for router redundancy and GLBP for load sharing between a pair of routers.

B.
Cisco Unified Border Element session information is check-pointed across the active and
standby router pair.

C.
It supports media and signal preservation when a switchover occurs.

D.
Only media streams are preserved when a switchover occurs.

E.
It can leverage either HSRP or VRRP for router redundancy.

F.
The SIP media signal must be bound to the loopback interface.

Explanation:
Configure box-to-box redundancy when you:
•Expect the behavior of the CSSs to be active/standby (only the master CSS processes flows)
•Can configure a dedicated Fast Ethernet (FE) link between the CSSs for the VRRP heartbeat
Do not configure box-to-box redundancy when you:
•Expect the behavior of the CSSs to be active-active (both CSSs processing flows). Use VIP
redundancy instead.
•Cannot configure a dedicated FE link between the CSSs.
•Require the connection of an Layer 2 device between the redundant CSS peers.