Dell Force10 MXL Blade MXL 10/40GbE Switch IO Module Configuration Guide - Page 126

www.dell.com | support.dell.com Configuring Enhanced Transmission Selection Enhanced transmission selection (ETS) provides a way to optimize bandwidth allocation to outbound 802.1p classes of converged Ethernet traffic. Different traffic types have different service needs. Using ETS, you can create groups within an 802.1p priority class to configure different treatment for traffic with different bandwidth, latency, and best-effort needs. For example, storage traffic is sensitive to frame loss; interprocess communication (IPC) traffic is latency-sensitive. ETS allows different traffic types to coexist without interruption in the same converged link by: • Allocating a guaranteed share of bandwidth to each priority group • Allowing each group to exceed its minimum guaranteed bandwidth if another group is not fully using its allotted bandwidth To configure ETS and apply an ETS output policy to an interface, you must: 1. Create a QoS output policy with ETS scheduling and bandwidth allocation settings. 2. Create a priority group of 802.1p traffic classes. 3. Configure a DCB output policy in which you associate a priority group with a QoS ETS output policy. 4. Apply the DCB output policy to an interface. ETS Prerequisites and Restrictions The following prerequisites and restrictions apply when you configure ETS bandwidth allocation or queue scheduling and apply a QoS ETS output policy on an interface: • Configuring ETS bandwidth allocation or a queue scheduler for dot1p priorities in a priority group is applicable only if the DCBX version used on a port is CIN (refer to Configuring DCBX on an Interface). • When allocating bandwidth or configuring a queue scheduler for dot1p priorities in a priority group on a DCBX CIN interface, take into account the CIN bandwidth allocation (Configuring Bandwidth Allocation for DCBX CIN) and dot1p-queue mapping (Table 8-1). • Although an ETS output policy does not support WRED, ECN, rate shaping, and rate limiting because these parameters are not negotiated by DCBX with peer devices, you can apply a QoS output policy with WRED and/or rate shaping on a DCBX CIN-enabled interface (refer to Configure Port-based Rate Shaping on page 420 and Weighted Random Early Detection). In this case, the WRED or rate shaping configuration in the QoS output policy should take into account the bandwidth allocation or queue scheduler configured in the ETS output policy. • You can only use a QoS ETS output policy in association with a priority group in a DCB output policy and cannot be applied to an interface as a normal QoS output policy (refer to Applying an ETS Output Policy for a Priority Group to an Interface and Create an Output QoS Policy). Note: The IEEE 802.1Qaz, CEE, and CIN versions of ETS are supported. 124 | Data Center Bridging (DCB)