Please enable JavaScript.
Coggle requires JavaScript to display documents.
Establishing Frame Relay Connection - Coggle Diagram
Establishing Frame Relay Connection
Frame Relay
Operates at a higher speed (44.3 Mbps)
Operates only in physical and data link layers
Is less expensive than other WAN connection such as X.25
Has error detection at the data link layer only
Provides faster transmission for media that are more reliable and protocols that have flow and error control at the higher layers
Frame Relay Components
Data Terminal Equipment (DTE)
Data Communications Equipment (DCE)
Access link
Local access rate
DLCI
LMI
Committed Information (CIR)
Committed burst (Bc)
Excess Burst (Be)
Forward explicit congestion notification (FECN)
Backward explicit congestion notification (BECN)
Discard Eligibility (DE) indicator
Frame Relay Encapsulation Types
Cisco
Internet Engineering Task Force (IETF)
Virtual Circuit
A Virtual Circuit (VC) represents the path on which the frame travels. Virtual circuits enable you to compare Frame Relay to leased physical circuit
There are two types of virtual circuits, such as:
Permanent Virtual Circuit (PVC)
Switched Virtual Circuit (SVC)
DLCI Addressing Details
Protocols being routed
Broadcast traffic
Speed of line
Static Routes
Size of routing protocol and SAP updates
Concerns of Network Layer and Frame Relay
Layer 3 addressing with Frame Relay
Broadcast handling
A subnet that contains all the Frame Relay Data Terminal Equipments (DTE)
A subnet for each virtual circuit
Hybrid of the above two options
Broadcast Handling
The Frame Relay can send copies of broadcast over all the virtual circuits
The Frame Relay does not have the capability to replicate and deliver across multiple virtual circuits to several destinations
The routers need to send broadcast for certain features to activate their functioning
Frame Relay Service Internetworking
Frame Relay networks use Asynchronous Transfer Mode (ATM) in the core of the Frame Relay network
The working of ATM is similar to a Frame Relay. However, ATM has certain features that make it more effective than Frame Relay
The service provider uses the ATM to build the core of the Frame Relay networks as shown in figure
Configuring Frame Relay Subinterfaces
Frame Relay subinterfaces provide a solution to the problem of split horizon on the partially meshed Frame Relay networks
Cisco routers support two types of subinterfaces given as follows:
Point-to-point subinterface
Multipoint subinterfaces
Frame Relay Congestion Control
Discard Eligibility (DE)
Forward-explicit congestion notification (FECN)
Backward-explicit congestion notification (BECN)
Frame Relay Error Checking
Frame Relay uses cyclic redundancy check (CRC) error checking mechanism
The CRC compares two derived values from the two mathematical functions computed at the source and the destination devices
This determines whether an error occurred during the transmission of data from source to destination