QoS queuing allows a network administrator to allocate bandwidth based on a QoS traffic class. In a virtualized environment, virtual machine (VM) interfaces are set up to handle VM traffic over the network. Even though the environment is “virtual”, the traffic sent outside of the host or server must still travel over a physical link. A traffic class may be allocated a portion of the available bandwidth on one or more physical links, e.g., traffic class X may be allocated 40% of available bandwidth on physical link 1 and 60% of available bandwidth on physical link 2. Other traffic classes may be similarly allocated. Assuming that there are two physical links of equal capacity then traffic class X is allocated 50% of the overall available bandwidth.
When two (or more) physical links are configured with the same network connectivity (e.g. VLANs) and queuing policy, each can be used to carry the server traffic. The two (or more) physical links may be logically combined to form an uplink group, port channel (PC), or port group. PCs and port groups are examples of an uplink group. Each of the physical links may be referred to as a member or member of the uplink group or PC. There may be more than one such group of physical links within a host. A VM interface may be tied (pinned) to a specific physical link with the group or its traffic may be distributed among multiple members of the group, i.e., in some implementations the VM interfaces are not pinned to specific physical links.