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| 8.7 |  | Traffic Shaping |
| 8.7.2 |  | Generic Traffic Shaping (GTS) |

Traffic shaping allows the control of traffic going out an interface in order to match its transmission to the speed of the remote target interface and to ensure that the traffic conforms to the policies contracted for it. Traffic adhering to a particular profile can be shaped to meet downstream requirements, thereby eliminating bottlenecks in topologies with data-rate mismatches.

Generic Traffic Shaping (GTS) shapes traffic by reducing outbound traffic flow to avoid congestion by constraining traffic to a particular bit rate using the token bucket mechanism. GTS is applied on a per-interface basis and can use access lists to select the traffic to shape. It 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 BECN signals, or simply to shape to a specified rate.

Generic traffic shaping can be used by a service provider to define the data rate independently of the physical link clock rate. An ISP may provide customers with a physical T1 regardless of the data rate they are paying for. The actual rate supplied can then be 128 Kbps configured using GTS. Should the customer wish to upgrade to a 1Mbps service, this can be achieved with a minor configuration change.