Layer 4 destination port DSCP remapping

../../_images/trsp-l4-dscp-remap.png

This task verifies the expected DSCP (Differentiated Services Code Point) remapping between two points in your network, with specific UDP or TCP destination ports indicated.

Test procedure

UDP or TCP packets are sent from the sender Test Agent to the receiver Test Agent with a specified destination port number, and it is checked how the DSCP is mapped by the network. This is repeated for each port in the specified port ranges.

Fail criteria

The test fails for a port range if the DSCP mapping for any port in that range differs from what is expected.

Limitations

IPv6 is not supported for this task.

Parameters

General

  • Sender: The sender Test Agent interface.

  • Receiver: The receiver Test Agent interface.

  • Protocol: The protocol to use: UDP or TCP. Default: UDP.

  • Port ranges: Port ranges, separated by commas (,). Default: “80-90” (i.e. a single range).

  • Sent DSCP: Sent DSCP or IP Precedence value. Default: “0 / IPP 0”.

  • Expected DSCP: Expected received DSCP or IP Precedence value. Default: “0 / IPP 0”.

  • Wait for ready: Time to wait before starting this test step. The purpose of inserting a wait is to allow all Test Agents time to come online and acquire good time sync. Min: 1 min. Max: 24 hours. Default: “Don’t wait”, i.e. zero wait time.

Result metrics

  • Pass/fail for each tested port range

Remark

This test can alternatively be used simply to find out which ports are open between the two points in the network (by testing the full range of existing port numbers).