Foundation Summary 277
Table 9-6 reviews the commands to implement Frame Relay traffic shaping.
Table 9-5
Frame Relay Traffic Parameters
Parameter
Description
CIR
The average rate you want to transmit. This is generally not the same as the CIR
provided by the telco. This is the amount you want to send in periods of
noncongestion.
Be
The amount of excess data allowed to be sent during the first interval once credit is
built up. Transmission credit is built during periods of no transmission. The credit is
the burst size. Full credit is typically CIR
ч 8.
Bc
The amount of data to send in each Tc interval.
Tc The
Bc
ч CIR time interval. The time interval shouldn't exceed 125 ms (almost
always 125 ms).
MinCIR
The minimum amount of data to be sent during periods of congestion. This is
usually what you get from the telco. MinCIR defaults to one-half of CIR.
PIR
Highest possible rate of transmission on a given interface.
MIR
Slowest rate of transmission on a give interface.
Interval
Bc
ч CIR. The maximum is 125 ms, or 1/8 second.
Byte Increment
Bc
ч 8. This value must be greater than 125.
Limit
Byte Increment + Be
ч 8 (in bytes).
Table 9-6
Frame Relay Traffic Shaping Commands
Command
Function
frame-relay traffic-shaping
Enables traffic shaping on a Frame Relay interface. This
command should be issued at the major interface.
map-class frame-relay name
Used to define a profile for the traffic parameters for any
circuits to which it is applied. The name is case-sensitive
when applied to a circuit.
frame-relay traffic-rate average [peak]
Defines average and peak transmission rates for any circuit
to which the map class containing this command is
applied.
frame-relay adaptive-shaping becn
Enables the router to respond to inbound frames with
BECN markers. Once a BECN frame is received, the
transmission rate is reduced.
frame-relay cir [in | out] bits
Defines the CIR for a map class.
frame-relay bc [in | out] bits
Defines the Bc for a map class.
frame-relay be [in | out] bits
Defines the Be for a map class.
continues