Avaya Configuring Frame Relay Services Manual de usuario descargar pdf (Pagina 53)

Frame Relay Overview

117376-C Rev. 00

2-23

If you enable the congestion control feature, you can specify the number of

FECN/BECN bits the router receives in a given time period before it stops

transmitting frames. While frames are going across the network, the frame relay

interface checks received packets for FECN and BECN bits set to 1. If the

interface receives the specified number of bits during the designated time period,

frame relay drops all traffic destined for the PVC where there is congestion. When

the interface no longer receives these congestion notifications, the router resumes

transmission.

For example, suppose you set the congestion timer to 0.5 second and the

congestion count to 3. In this case, if an interface receives 3 FECNs or BECNs

within 0.5 second, the node stops sending frames (although it continues to receive

frames for this PVC). If the interface receives no FECNs or BECNs during the

next 0.5 second, the router resumes transmission. For instructions on configuring

the congestion attributes or parameters, see “Controlling Congestion for PVCs”

on page 3-22 and “Controlling Congestion for SVCs” on page 3-58.

If you enable congestion control and also enable traffic shaping, you can throttle,

which means queue, congested traffic rather than drop it by choosing the value,

Throttle, in the Congestion Method attribute or parameter (for a description of the

Congestion Method parameter, see page A-11).

Traffic Shaping

Traffic shaping relieves bottlenecks in topologies with high-speed connections to

the central site, and low-speed connections at remote sites (as in Figure 2-8

page 2-20

). Committed information rate enforcement and quality of service are

the major components of Bay Networks traffic shaping.

Committed Information Rate

The committed information rate (CIR) is the rate at which the network supports

data transfer under normal operations. Its name is descriptive: you have a contract

with your carrier, who has committed to providing a given throughput, here called

the committed information rate. The CIR is measured in bits per second. You

configure this value that the carrier provides per virtual circuit.

1 2 ... 48 49 50 51 52 53 54 55 56 57 58 ... 239 240

Sin comentarios

Avaya Configuring Frame Relay Services Manual de usuario Pagina 53