IPv4 type of service or IPv6 traffic class mapping configuration

There are two mappings provided by the SetSubnetPrioTosMask statement:

• IPv4 type of service (ToS) or IPv6 traffic class to device priority

  Quality of service (QoS) support in z/OS® Communications Server allows the IPv4 ToS byte, also known as the Differentiated Services (DS) field, or the IPv6 traffic class to be set for outbound IP packets according to defined policies managed by the z/OS Communications Server UNIX Policy Agent. When IP packets are sent out over QDIO devices, the ToS/DS or traffic class value is mapped to a QDIO priority value. Device priority values are 1-4, where 1 is the highest priority.

• IPv4 ToS or IPv6 traffic class to VLAN user priority

  ToS/DS or traffic class values can be mapped to user priorities for directly attached LANs using the OSA-Express feature in QDIO mode. VLAN user priority values are 0-7, where 7 is the highest priority. This allows assigned user priorities to be propagated through such networks, resulting in no loss of priority information for data being served by z/OS.

The following example shows a mapping of various ToS byte or traffic class values to associated interface priority values. Note that the mapping can be applied to individual interfaces or all interfaces:

• The first example defines a mapping for a specific interface. Note that the specified interface must be a valid interface specified in the HOME list. The second example shows a different mapping for all other interfaces.
• The subnet mask defines the bits in the ToS byte or traffic class that are significant. These examples use the leftmost 3 bits.
• The first example shows a set of mappings defining the complete set of ToS byte or traffic class values and the device and VLAN user priorities to be assigned for each value.
• The second example shows a set of mappings defining the complete set of ToS byte or traffic class values and the device priority to be assigned for each value.

SetSubnetPrioTosMask
{
  SubnetAddr         10.10.1.5
  SubnetTosMask      11100000
  PriorityTosMapping 1 11100000 7
  PriorityTosMapping 1 11000000 7
  PriorityTosMapping 2 10100000 6
  PriorityTosMapping 2 10000000 5
  PriorityTosMapping 2 01100000 5
  PriorityTosMapping 3 01000000 3
  PriorityTosMapping 4 00100000 2
  PriorityTosMapping 4 00000000 0
}
SetSubnetPrioTosMask
{
  SubnetTosMask      11100000
  PriorityTosMapping 1 11100000
  PriorityTosMapping 1 11000000
  PriorityTosMapping 1 10100000
  PriorityTosMapping 1 10000000
  PriorityTosMapping 2 01100000
  PriorityTosMapping 2 01000000
  PriorityTosMapping 3 00100000
  PriorityTosMapping 4 00000000
}