A network administrator needs to configure a router for a Frame Relay connection to a non-Cisco
router. Which of the following commands will prepare the WAN interface for this connection?

A.
Router(config-if)# encapsulation frame-relay ansi

B.
Router(config-if)# encapsulation frame-relay ietf

C.
Router(config-if)# encapsulation frame-relay isl

D.
Router(config-if)# encapsulation frame-relay q933a

Explanation:
In general, the IETF Frame Relay encapsulation should be used when connecting a Cisco router
to non-Cisco equipment across a Frame Relay network. The IETF Frame Relay encapsulation
allows interoperability between equipment from multiple vendors. Both Cisco and IETF
encapsulations for Frame Relay can be configured on a per-virtual-circuit (VC) basis. This gives
greater flexibility when configuring Frame Relay in a multi-vendor environment. A user can specify
the Frame Relay encapsulation types to be used on different virtual circuits configured under the
same physical interface.