In order for upper-layer data to be transmitted across a Frame Relay network, it obviously needs to be framed. Cisco routers support two different Frame Relay encapsulation types, known as Cisco and IETF. By default, a Cisco router will use Cisco encapsulation on Frame Relay interfaces, unless IETF is explicitly specified. IETF encapsulation is usually used when connecting both Cisco and non-Cisco devices across a Frame Relay network. However, another issue at hand is the framing method in use by your service provider. As a general rule, it’s always a good idea to obtain this information before beginning the configuration process.
