QoS Support on the MSFC and FlexWAN 341
The FlexWAN module supports numerous 7200/7500 WAN port adapters in the individual
bays. This support allows for the integration of existing available hardware. However, the
FlexWAN does not support LAN port adapters, double-wide port adapters, or service
modules, such as the VPN accelerator module. Double-wide port adapters are not supported
due to the availability of separate processors for each bay. Table 9-3 shows which 7200/
7500 WAN port adapters are supported with the FlexWAN module.
QoS Support on the MSFC and FlexWAN
The MSFC and FlexWAN offer a broad range of QoS mechanisms. The QoS support on the
MSFC and FlexWAN are derived from the distributed QoS support for a VIP, available on
the 7500. Therefore, the MSFC and FlexWAN provide intelligent distributed QoS services,
which allow QoS policies to be extended across the MAN and WAN.
The QoS features available for the MSFC and FlexWAN are primarily configured using the
Modular QoS command-line interface (MQC), introduced in chapter 5. The MQC enables
the administrator to classify traffic, define policies, and apply those policies in a systematic
modular fashion. For a more detailed discussion regarding the MQC, refer to Chapter 5.
When a WAN packet arrives or departs a FlexWAN interface, the FlexWAN is responsible
for applying its own QoS mechanisms to that packet. When the packet is received on the
WAN interface, any configured ingress QoS policies defined on the interface are applied to
the packet. The same behavior applies to egress packets. When the forwarding decision has
been made and the packet is encapsulated with the appropriate WAN header, any egress
QoS policies defined on the interface are applied to the packet, which is then queued for
transmission. This behavior is particularly true for policing functions on the FlexWAN. The
FlexWAN is responsible for policing traffic streams on its interfaces, due to the potential
discrepancies that may result from the variation in header length between a WAN and
Table 9-3 Supported 7200/7500 WAN Port Adapters
T1/E1 T3/E3 HSSI ATM
Packet over
SONET
PA-4T+ PA-T3 PA-H PA-A3-T3 PA-POS-OC3MM
PA-8T-V35 PA-2T3 PA-2H PA-A3-E3 PA-POS-OC2SMI
PA-8T-X21 PA-T3+ PA-A3-OC3MM PA-POS-OC3SML
PA-8T-232 PA-2T3+ PA-A3-OC3SMI
PA-MC-4T1 PA-E3 PA-A3-OC3SML
PA-MC-8T1 PA-2E3 PA-T1-IMA
PA-MC-8TE1+ PA-MC-T3
PA-MC-8E1/120 PA-MC-2T3+
PA-MC-STM-1 PA-MC-E3
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