Policy-based routing enables the TCP/IP stack to make routing decisions that take into account criteria other than just the destination IP address. The additional criteria can include job name, source port, destination port, protocol type (TCP or UDP), source IP address, NetAccess security zone, and multilevel secure environment security label. Policy-based routing might be useful in the following sample scenarios:

• You might want to use high-bandwidth links for batch traffic, but for interactive traffic you prefer low-latency links. In this scenario, you can define policies such that Telnet traffic is routed over the low-latency links, and FTP traffic is routed over the high-bandwidth links.
• You could define a policy to ensure that traffic that is tagged with a security label and zone is routed to a secured network over an appropriate outbound interface.
• You might want to control the links that Enterprise Extender traffic uses to keep that traffic from being impacted by other IP traffic loads.

For more information about policy-based routing, see z/OS Communications Server: IP Configuration Guide.