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http:\\ciscocertifications.info
Committed Information Rate (CIR)
The rate, in bits per second, at which the Frame Relay switch agrees to transfer data.
*Keypoints:DLCIs are used to distinguish between PVCs.Frame Relay operates at the Data Link and Physical layers.You can use the "show interface" command to display the LMIs and DLCIs on a frame relay en-abled interface.The default bandwidth setting for a serial DCE interface is T1 (1.544 Mbps).Know what command is used to configure a subinterface.Know that multipoint specifies that a frame relay subinterface is configured as a single subnet.LMI type is autosensed.You must configure static maps if a Frame Relay router does not support Inverse ARP.You must remove any network address assigned to an interface and configure the local DLCI whencreating a Frame Relay subinterface.Know the definition of CIR.Know how subinterfaces are numbered.Monitoring Frame Relayshow frame-relay ip
- Shows frame relay ip statistics
show frame-relay lmi
- Shows LMI statistics
show frame-relay map
- Shows map table
show frame-relay pvc
- Shows PVC Statistics Also DLCI Info
show frame-relay route
- Shows frame relay routes
show frame-relay traffic
- Shows protocol statistics
The Show Interface command also shows Frame Relay information on a specific interface. The showip route command will also show which routers are reachable.
*Keypoints:The "show frame-relay map" or "show ip route" commands can be used to show which IP routersare reachable. Use the "show frame-relay pvc" command to display DLCI info. Use the "show frame-relay lmi" command to view LMI traffic statistics.ISDN
Integrated Services Digital Network (ISDN) is a digital service designed to run over existing telephone
networks. ISDN can support both data and voice simultaneously. ISDN encompasses the OSI Physical,
Data Link, and Network Layers.
ISDN networking can provide up to 128 Kbps with a PPP Multilink connection to corporate networks
or the Internet. A Basic Rate Interface (BRI) connection can also be used as a backup line in case the
primary link goes down. In this case you have to set the desirability of the ISDN link to be very low. In
other words only use if there is no other way.
ISDN has the following benefits over standard telephone connections:
1)
Data transfer is faster than typical modems
2)
Call setup is faster
3)
ISDN can carry voice, video, and data traffic