258 CHAPTER 17: CONFIGURING FRAME RELAY
Configure Frame Relay
QoS Quality of Service (QoS) is a set of technologies adopted to meet the users'
requirements in throughput, delay jitter, delay and packet loss ratio. Briefly
speaking, QoS technologies provides network services of different qualities for
different requirem ents.
On a Frame Relay interface, the user can use the general QoS to provide the
services, such as traffic policing, traffic shaping, congestion management, and
congestion avoidance. For details, please refer to the relative description in the
part of QoS.
Furthermore, a Frame Relay network has its own QoS mechanisms, including
Frame Relay traffic shaping, Frame Relay traffic policing, Frame Relay congestion
management, Frame Relay discard eligibility (DE) rule list and Frame Relay
queueing management. According to different requirements, the network service
provider can provide various services, such as bandwidth restriction and
bandwidth reservation.
Compared with the general QoS, Frame Relay QoS can provide the service of QoS
for each PVC on an interface. However, the general QoS can only provide the
service of QoS on the whole interface. Therefore, the Frame Relay QoS can provide
more flexible quality services for users.
Figure 81 Frame Relay QoS application
Frame Relay Traffic Shaping
The Frame Relay traffic shaping can control the normal traffic size and the burst
traffic size transmitted from a PVC and enable the Frame Relay PVC to transmit
these packets at a relatively average rate.
In a Frame Relay network, the bottleneck will often occur at the boundary of
segments if the bandwidths of different segments do not match. As shown in
Figure 82, Router B transmits packets to Router A at the rate of 128 kbps whereas
the maximum interface rate of Router A is only 64 kbps. In this case, the
bottleneck will occur at the place where Router A is connected to the Frame Relay
network, and thereby resulting in the congestion that prevents the data from
normal transmitting.
Remove the association between a Frame Relay
class and a Frame Relay interface or PVC undo fr-class class-name
Enable the Frame Relay traffic shaping fr traffic-shaping
Disable the Frame Relay traffic shaping undo fr traffic-shaping
Frame Relay
Network
Traffic Shaping Traffic Policing
Router B
Router A
DTE NNI
DCE
Congestion
Management
DE Rule
Data flow direction