# Quality of Service

Quality of Service (QoS) allows the adapter to send and receive IEEE 802.3ac tagged frames. 802.3ac tagged frames include 802.1p priority-tagged frames and 802.1Q VLAN-tagged frames. In order to implement QoS, the adapter must be connected to a switch that supports and is configured for QoS. Priority-tagged frames allow programs that deal with real-time events to make the most efficient use of network bandwidth. High priority packets are processed before lower priority packets. Microsoft* Windows* 2000, Windows XP, and Windows Server* 2003 support QoS.

Tagging is enabled and disabled using the "QoS Packet Tagging" field in the Advanced tab in Intel® PROSet.

Once QoS is enabled in Intel PROSet, you can specify levels of priority based on IEEE 802.1p/802.1Q frame tagging.

Microsoft* Windows* 2000, Windows XP, and Windows Server* 2003 have a utility for 802.1p packet prioritization. For more information, see the Windows system help and Microsoft's knowledge base.

| NOTE: The first generation Intel® PRO/1000 Gigabit Server Adapter (PWLA 8490) does not support QoS frame tagging.

## QoS Load Balancing in a Team

Adaptive Load Balancing (ALB) and Static Link Aggregation (SLA) teams can use QoS load balancing to add priority as a factor in the load balancing process. Teams with QoS load balancing enabled will try to expedite high priority packet transmission.

| NOTE: QoS Load Balancing Bandwidth reserves whole adapters for high priority traffic. It does not do real-time flow analysis and control. For example, if you have a three-adapter team and reserve 95% of the bandwidth for high priority traffic, two adapters are reserved for high priority traffic; the third adapter can pass both high and low priority traffic.

`Last modified on 12/14/04 11:35a Revision 1`