HP Virtual Connect for c-Class BladeSystem Version 4.01 User Guide

Virtual Connect networks 102
The following diagram illustrates how VC receives traffic and categorizes it into classes. Packets can be
reordered based on priority as shown for packet number 3. Packets can also be dropped during congestion
as shown for packet number 5.
Prior to the VC 4.01 release, VC QoS support was limited apart from dynamic Max rate limiting bandwidth
control. VC Ethernet modules passed Layer 2 and Layer 3 markings in VLAN tunnel mode but in some cases
removed L2 markings in mapped mode. VC would not perform any traffic classification, marking, policing,
or traffic shaping for Ethernet traffic flows. FCoE traffic is prioritized and classified In FlexFabric modules but
controls were fixed and not exposed to administrators.
The diagram below illustrates a pass-through configuration where packets are transmitted in the same order
as they are received.
The QoS feature introduced in VC 4.01 allows administrators to configure traffic queues for different priority
network traffic, categorize and prioritize ingress traffic and adjust DOT1P priority settings on egress traffic.
Administrators can use these settings to ensure that important traffic receives the highest priority handling
while less important traffic is handled at a lower priority.
The default QoS configuration in VC 4.01 is pass-through. Two other configuration types for "Custom with
FCoE Lossless ("Custom (with FCoE Lossless)" on page 103)" and "Custom without FCoE Lossless ("Custom
(without FCoE Lossless)" on page 106)" provide administrators with basic settings that can be further tuned
depending on whether FCoE traffic is present in the Virtual Connect environment.
Quality of Service screen
The Quality of Service (on page 101) feature allows users to prioritize network traffic to enhance
performance.