PWE3 Trace Test
The NQA PWE3 trace test detects the MPLS-based PW path and collects statistics about each device along the path.
The PWE3 trace test process is as follows:
The source constructs an MPLS Echo Request packet with the TTL set to 1 and sends it through a specified PW. When the first-hop device receives the packet, its TTL decreases to 0 and it times out. The first-hop device then returns an MPLS Echo Reply packet.
Upon receiving the MPLS Echo Reply packet from the first-hop device, the source constructs an MPLS Echo Request packet with the TTL set to 2 and sends it through the PW. When the second-hop device receives the packet, its TTL decreases to 0 and it times out. The second-hop device then returns an MPLS Echo Reply packet.
The source continues to send MPLS Echo Request packets, with the TTL increasing by 1 each time. This process is repeated until the source has collected information about every device on the PW.
The source obtains the PW path from the source to the destination from the MPLS Echo Reply packets received from each hop. It also collects statistics about each device along the path.
PWE3 trace test results and historical records are collected in test instances. You can run commands to view the test results and historical records.