CCIE Practical Studies: Security (CCIE Self-Study)

Frame Relay Signaling

Frame Relay was not designed to include a built-in mechanism to address network outages; instead, the Local Management Interface (LMI) signaling protocol was developed to exchange keepalives and to pass administrative information, such as addition, deletion, or failure of PVCs. These messages are only exchanged between the DTE/DCE pair and are never transmitted across the network in-band of the PVC.

Within Cisco IOS Software, you can assign the LMI type by using a static assignment or by using a feature called LMI autosense. A statically defined LMI type comes in three different standards:

• ansi— The Annex D standard defined by the American National Standards Institute (ANSI) Standard T1.617

• q.933— The ITU-T Q.933 Annex ...