White Papers

The following figure shows iSCSI optimization between servers in a server enclosure and a storage array in which an Aggregator
connects installed servers (iSCSI initiators) to a storage array (iSCSI targets) in a SAN network. iSCSI optimization running on
the Aggregator is configured to use dot1p priority-queue assignments to ensure that iSCSI traffic in these sessions receives
priority treatment when forwarded on Aggregator hardware.
Figure 61. iSCSI Optimization Example
Monitoring iSCSI Traffic Flows
The switch snoops iSCSI session-establishment and termination packets by installing classifier rules that trap iSCSI protocol
packets to the CPU for examination.
Devices that initiate iSCSI sessions usually use well-known TCP ports 3260 or 860 to contact targets. When you enable iSCSI
optimization, by default the switch identifies IP packets to or from these ports as iSCSI traffic.
You can configure the switch to monitor traffic for additional port numbers or a combination of port number and target IP
address, and you can remove the well-known port numbers from monitoring.
Information Monitored in iSCSI Traffic Flows
iSCSI optimization examines the following data in packets and uses the data to track the session and create the classifier entries
that enable QoS treatment:
● Initiator’s IP Address
● Target’s IP Address
● ISID (Initiator defined session identifier)
● Initiator’s IQN (iSCSI qualified name)
iSCSI Optimization
399