Enterprise QoS Solution Reference Network Design Guide
Enterprise QoS Solution Reference Network Design Guide
Enterprise QoS Solution Reference Network Design Guide
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WAN Edge Link-Specific <strong>QoS</strong> <strong>Design</strong><br />
3-30<br />
<strong>Enterprise</strong> <strong>QoS</strong> <strong>Solution</strong> <strong>Reference</strong> <strong>Network</strong> <strong>Design</strong> <strong>Guide</strong><br />
Chapter 3 WAN Aggregator <strong>QoS</strong> <strong>Design</strong><br />
to configure and difficult to manage, whereas IP CEF per-packet load balancing is not and has the lowest<br />
CPU impact of the load-sharing mechanisms. Therefore, IP CEF per-packet load balancing is<br />
recommended across multiple Frame Relay links to the same branch.<br />
Figure 3-12 High-Speed Frame Relay Links<br />
WAN Aggregator<br />
Frame Relay Link<br />
Multiple T1/E1<br />
Frame Relay<br />
Cloud<br />
Branch Router<br />
Note It is important to keep in mind that providers might have geographically dispersed paths to the same<br />
sites; therefore, the delay on one T1 FR link might be slightly higher or lower than the delay on another.<br />
This could cause TCP sequencing issues and slightly reduce effective data application throughput.<br />
<strong>Network</strong> administrators should keep these factors in mind when planning their WAN topologies.<br />
The max-reserved-bandwidth 100 command is not required on the interfaces because the queuing<br />
policy is not applied directly to the interface; instead, it is applied to another policy (the MQC-based<br />
Frame Relay traffic-shaping policy). Example 3-20 shows the configuration for a high-speed Frame<br />
Relay link.<br />
Example 3-20 High-Speed (Š Multiple T1/E1) Frame Relay <strong>QoS</strong> <strong>Design</strong> Example<br />
!<br />
policy-map MQC-FRTS-1536<br />
class class-default<br />
shape average 1460000 14600 0 ! Enables MQC-Based FRTS<br />
service-policy WAN-EDGE ! Queues packets headed to the shaper<br />
!<br />
…<br />
!<br />
interface Serial2/0<br />
no ip address<br />
encapsulation frame-relay<br />
no fair-queue<br />
frame-relay traffic-shaping<br />
!<br />
interface Serial2/0.12 point-to-point<br />
description 1536kbps FR Circuit to RBR-3745-Left<br />
ip address 10.1.121.1 255.255.255.252<br />
ip load-sharing per-packet ! Enables IP CEF Per-Packet Load-Sharing<br />
frame-relay interface-dlci 102<br />
class FR-MAP-CLASS-1536 ! Binds the map-class to FR DLCI 102<br />
!<br />
interface Serial2/1<br />
no ip address<br />
encapsulation frame-relay<br />
serial restart_delay 0<br />
!<br />
interface Serial2/1.12 point-to-point<br />
description 1536kbps FR Circuit to RBR-3745-Left<br />
ip address 10.1.121.5 255.255.255.252<br />
ip load-sharing per-packet ! Enables IP CEF Per-Packet Load-Sharing<br />
frame-relay interface-dlci 112<br />
class FR-MAP-CLASS-1536 ! Binds the map-class to FR DLCI 112<br />
Version 3.3
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