ShortNotes for CCIE written exam - Frame Relay

Packet switch technology, work at the physical and data link layers of OSI model.
Devices attached to Frame Relay WAN - DTE, DCE
DTE - teminating equipment - routers/bridges/PC
DCE - Carrier-owned devices - provide clocking and switching - Frame Relay switch
Virtual circuit - PVC, SVC
SVC - temporary connections - Call setup, data transfer, Idle, Call termination
PCV - permantely established connections - data transfer, Idle

Data link conneciton identifier (DLCI)
Circuit identified by DLCI (assigned by service provider)
locally significance (unique in LAN but not necessarily in FrameRelay WAN)

Congestion Control mechanisms
BECN - Backward-explict congestion notification
FECN - Forward-explict congestion notification
DE - Discard Eligibility (Indicate that a frame has lower importance than other)
CRC - Frame relay error checking

Local Management Interface (LMI)
Global addressing
virtual status messages (syn between DTE & DCE, report status of PVC)
multicasting
LMI type - Cisco, ANSI , Q.933A

Configuration
Under main interface (by default, it's multipoint)
int S1/0
encapsulation frame-relay (Dynamically learn by Inv-arp)
frame-relay map ip 192.168.1.1 102 broadcast (static mapping)

Under subinterface
intS1/0.1 multi-point (use either dynamic or static)
frame-relay interface-dlci 102 (specifically assign DLCI)

Verificarion
#show frame-relay map
Serial1/0 (up): ip 192.168.1.1 dlci 102(0x191,0x6410), dynamic,broadcast,, status defined, active

#show frame-relay pvc
PVC Statistics for interface Serial (Frame Relay DCE)DLCI = 102, DLCI USAGE = LOCAL, PVC STATUS = ACTIVE, INTERFACE = Serial1/0