Chapter 4 FCIP over IP/MPLS Core
QoS Requirements in FCIP
QoS Requirements in FCIP
Currently, most of the FCIP links are dedicated for pure Fibre Channel traffic. But in most cases if QoS is enabled, most of the SAN applications can be transported across the same traffic engineered infrastructure shared with traditional IP traffic. Because there are several QoS models, make sure the right Differentiated Services Code Point (DSCP) is applied to get the assumed results.
To ensure that one QoS model does not conflict with another application (that is, they can run on the same network), it is important for a common set of QoS priority markings to be used across the entire SP network that is in agreement with enterprise traffic. Following is a recommended set of class of service (COS) and MPLS EXP encodings for a typical application:
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Note The above DSCP values are just a recommendation; a network administrator may choose another consistent set of numbers if desired.
Cisco MDS supports DSCP values for marking all IP packets in the type of service (TOS) field in the IP header. You can specify different values for control and data:
•The control DSCP value applies to all FCIP frames in the control TCP connection.
•The data DSCP value applies to all FCIP frames in the data connection.
If the FCIP link has only one TCP connection, that data DSCP value is applied to all packets in that link.
The following command configures the control TCP connection and data connection to mark all packets on that DSCP value.
The following command reverts the switch to its factory default:
QoS can also be applied using the Fabric Manager/Device Manager GUI. Figure
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