9-9
Cisco 10000 Series Router Quality of Service Configuration Guide
OL-7433-09
Chapter 9 Shaping Traffic
Traffic Shaping
Using information contained in the BECN-tagged packets received from the network, FRTS can
dynamically throttle (decrease) traffic. When an interface configured with FRTS receives a BECN, it
immediately decreases its maximum rate and holds the packets in the buffers of the router to reduce the
data flow from the router into the Frame Relay network. If, after several intervals, the interface has not
received another BECN and traffic is waiting in the queue, the maximum rate increases slightly. FRTS
decreases traffic on a per-VC basis and adjusts the transmission rate based on the number of
BECN-tagged packets received. The dynamically adjusted maximum rate is called the
derived rate
.
The derived rate is always between the upper bound and the lower bound rate configured on the interface.
For more information, see the
“Configuring Frame Relay Traffic Shaping” section on page A-5
.
Feature History for Frame Relay Traffic Shaping
Restrictions and Limitations for Frame Relay Traffic Shaping
•
Frame Relay traffic shaping applies only to Frame Relay PVCs.
Configuration Commands for Traffic Shaping
The following commands are used to configure class-based and hierarchical shaping (see the Cisco IOS
command reference documentation):
•
shape
•
shape percent
•
atm pvp
•
pvc
•
vbr-nrt
For information about configuring Frame Relay and Generic Traffic Shaping using Frame Relay legacy
commands, see the
“Configuring Frame Relay Traffic Shaping” section on page A-5
.
Cisco IOS Release
Description
Required PRE
Release 12.0(17)SL
The Frame Relay Traffic Shaping (FRTS) feature was
introduced on the router.
PRE1