Use the encapsulation frame-relay option to create a frame-relay interface of the IETF (RFC1490/RFC2427) type or non-IETF type. This command deletes the PPP interface associated with the current Serial interface. The PPP interface cannot be deleted if at least one IP interface is defined on it. Instead, the following message appears, You cannot update this L2 interface since L3 interfaces are defined on it.
By default, the Frame Relay encapsulation type for the main interface is IETF.
Note:
Non-IETF encapsulation is compatible with other vendors.