Monitoring Qos - HP 7102dl - ProCurve Secure Router Configuration Manual

Setting Up Quality of Service

Monitoring QoS

8-68
Configuring Frame Relay Fragmentation
It does not matter how much bandwidth you guarantee a queue if other frames
clog up the interface when it is their turn to be transmitted. You should enable
the interface to fragment large data frames to reduce serialization delay. Take
care to set the size at which the router starts fragmenting frames above the
size of VoIP frames, which, including the MLFR and IP headers, is 207 bytes.
Set the fragmentation threshold:
ProCurve(config-fr 1.102)# frame-relay fragment 210
Monitoring QoS
You should periodically monitor your network to ensure that traffic is actually
receiving the QoS specified by your organization. Problems with QoS may
include:
an excessive number of dropped packets
dropped telephone calls or breaks in the voice stream
jittery video streams
If the router is dropping an excessive number of packets, you may need to:
configure rate limiting on the Ethernet interfaces or on Frame Relay
subinterfaces
raise the threshold for WFQ conversational subqueues
To solve problems with low-quality VoIP and video streams, you should
reexamine the amount of bandwidth allocated to this traffic in low-latency
queues. You should also confirm that the QoS map entries for such queues are
actually selecting the correct traffic.
If the WAN simply demands more bandwidth from connections than the router
can provide, no number of QoS configurations will eliminate all problems. You
may need to reconsider your network and your organization's priorities and
place limits on certain kinds of traffic from certain subnets. Your organization
may also decide to renegotiate the WAN connection's CIR and EIR with a Frame
Relay provider or to increase the connection's bandwidth. (See Chapter 2:
Increasing Bandwidth.)