Reference Guide
Cos Rx Tx
-----------------------
0 0 0
1 0 0
2 0 0
3 0 587236
4 0 0
5 0 0
6 0 0
7 0 0
Supported Releases 10.3.0E or later
Enhanced transmission selection
Enhanced transmission selection (ETS) provides customized bandwidth allocation to 802.1p classes of trac. Assign dierent amounts of
bandwidth to trac classes (Ethernet, FCoE, or iSCSI) that require dierent bandwidth, latency, and best-eort treatment during network
congestion.
ETS divides trac into dierent priority groups using their 802.1p priority value. To ensure that each trac class is correctly prioritized and
receives required bandwidth, congure bandwidth and queue scheduling for each priority group. You can allocate more bandwidth to a
priority group to prioritize low-latency storage and server-cluster trac. Allocate less bandwidth to a dierent priority group to rate-limit
best-eort LAN trac.
ETS conguration notes
• ETS is supported on L2 802.1p priority (dot1p 0 to 7) and L3 DSCP (0 to 63) trac. FCoE trac uses dot1p priority 3 — iSCSI storage
trac uses dot1p priority 4.
• Apply these maps and policies on interfaces:
– Trust maps — OS10 interfaces do not honor the L2 and L3 priority elds in ingress trac by default. Create a trust map to honor
dot1p and DSCP classes of lossless trac. A trust map does not change ingress dot1p and DSCP values in egress ows. In a trust
map, assign a qos-group (trac class) to trusted dot1p/DSCP values. A qos-group number is used only internally to schedule
classes of ingress trac.
– QoS map — Create a QoS map to assign trusted dot1p and DSCP trac classes to lossless queues.
– Ingress trust policy — Congure a service policy to trust dot1p values in ingress trac.
– Egress queuing policy — Congure ETS for egress trac by assigning bandwidth to matching lossless queues in queuing class
and policy maps.
• Apply both PFC network-qos (input) and ETS queuing (output) policies on an interface to ensure lossless transmission.
Converged data center services
637