Table Of Contents
Distributed Traffic Shaping for Engine 0 Line Cards in the Cisco 12000 Gigabit Switch Router
Distributed Traffic Shaping (DTS) for Engine 0 Line Cards in the Cisco 12000 Gigabit Switch Router (GSR) is similar to the Generic Traffic Shaping feature implemented in Cisco IOS Release 11.2. Traffic shaping implemented for engine 0-type line cards provides different features from the distributed traffic shaping support in Cisco IOS Release 12.0(5)XE.
Table 1 Line Card Engines and Line Cards
Line Card Engine Line Cards Using DTS
Distributed Traffic Shaping supports traffic shaping regardless of the encapsulation. The traffic shaping implementation is per interface on a line card. Currently the traffic shaping scheme assumes one queue per interface. DTS on GSR can shape the output traffic to the specified bit rate. Excessive packets are stored in a buffer in the traffic shaping queue and transmitted later.
The DTS feature is one element used to manage the bandwidth of an interface to meet remote site requirements and to conform to a service rate that is provided on that interface.
DTS on GSR for engine 0 line cards is subject to the following restrictions:
•Subinterfaces are not supported.
•Implemented on the transmit side.
This feature is supported on the following Cisco 12000 series routers:
•Cisco 12016 series
•Cisco 12012 series
•Cisco 12008 series
•Line cards using engine 0 architecture
You must be running Cisco IOS Release 12.0(10)S or a later version of Cisco IOS Release 12.0 S.
Use the DTS for GSR feature with the weighted random early detection (WRED) feature. Otherwise, on a multiple-interface line card (for example, the QOC-12) one output interface can use all the output buffers and leave no output buffer for the other interfaces on that line card.
Supported MIBs and RFCs
No new or modified MIBs are supported by this feature.
Perform the following tasks to configure DTS on GSR:
Configure Distributed Traffic Shaping
To configure DTS on GSR for outbound traffic on an interface, use the following command in interface configuration mode:
traffic-shape rate bit-rate [burst-size
Configure traffic shaping for outbound traffic on an interface.
Note To obtain the best use of burst-size and excess-burst-size, specify only the required bit-rate value. The software will automatically tune the other values for optimum performance.
Monitor the DTS Configuration
To monitor the current traffic shaping configuration and statistics, use any of the following commands in EXEC mode:
Note The show traffic-shape statistics [interface-name] command is not supported on Engine 0 Line Cards in the Cisco 12000 Gigabit Switch Router .
This section provides the following configuration examples:
DTS on GSR (OC-12 POS Line Card)
The following configuration example shows how to enable DTS for an OC-12 POS line card in a GSR. The output on the interface is configured to limit all output to 5 Mbps.router(config)# interface pos 4/0router(config-if)# traffic-shape rate 5000000 625000 625000
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.0 command references.
To configure line cards in a Cisco 12000 GSR to use Distributed Traffic Shaping (DTS), use the traffic-shape rate interface configuration command. Use the no form of this command to disable DTS.
[no] traffic-shape rate bit-rate [burst-size [excess-burst-size]]
No default behavior or values.
You must use this command to enable the DTS on the engine 0 line cards. lists the line card engine and the line cards that use DTS. Using this command has no effect when non-supported line cards are installed in the GSR.
Table 2 Line Card Engines and Line Cards
Line Card Engine Line Cards Using DTS
To obtain the best use of burst-size and excess-burst-size, specify only the required bit-rate value. The software will automatically tune the other values for optimum performance.
The following example limits interface transmission to 5 Mbps on the selected line card interface:traffic-shape rate 5000000 625000 625000