Traffic Shaping And Queueing; Generic Traffic Shaping; How It Works - Cisco WS C4224V 8FXS - 200Mbps Ethernet Switch Software Configuration Manual

Generic Traffic Shaping

Traffic Shaping and Queueing

Generic Traffic Shaping

How It Works

Catalyst 4224 Access Gateway Switch Software Configuration Guide
10-6
Traffic shaping smooths traffic by storing traffic above the configured rate in a
queue.
When a packet arrives at the interface for transmission, the following sequence
occurs:
If the queue is empty, the arriving packet is processed by the traffic shaper.
1.
• If possible, the traffic shaper sends the packet.
Otherwise, the packet is placed in the queue.
•
If the queue is not empty, the packet is placed in the queue.
2.
When packets are in the queue, the traffic shaper removes the number of packets
it can send from the queue at each time interval.
Generic Traffic Shaping (GTS) shapes traffic by reducing outbound traffic flow
to avoid congestion. GTS constrains traffic to a particular bit rate using the token
bucket mechanism. See the section "What is a Token Bucket" in the Cisco IOS
Quality of Service Solutions Configuration Guide, Release 12.2:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos
_c/fqcprt4/qcfpolsh.htm#1000909
GTS applies traffic shaping on a per-interface basis and can use access lists to
select the traffic to shape. GTS works with a variety of Layer 2 technologies,
including Frame Relay, ATM, Switched Multimegabit Data Service (SMDS), and
Ethernet.
On a Frame Relay subinterface, GTS can be set up to adapt dynamically to
available bandwidth by integrating backward explicit congestion notification
(BECN) signals. GTS also can be shape traffic to a specified rate. GTS can be
configured on an ATM/ATM Interface Processor (AIP) interface to respond to the
Resource Reservation Protocol (RSVP) feature signalled over statically
configured ATM permanent virtual circuits (PVCs).
Chapter 10 Traffic Shaping
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