Testing network communications links

Apparatus for performing bi-directional testing in a link of a communications network comprising local test apparatus for connection to a local end of the link and remote test apparatus for connection to a remote end of the link, the local test apparatus and the remote test apparatus each being operable to transmit and receive in-band test traffic over the link and analyze received test traffic according to prescribed test procedures to obtain test results;

• the local test apparatus being operable to transmit to the remote test apparatus via the link test information including test management information defining the prescribed test procedures to be carried out upon local-to-remote test traffic to be transmitted by the local test apparatus and received by the remote test apparatus;
• the remote test apparatus being operable to receive the test management information, determine the test procedures to be carried out upon subsequently-received local-to-remote test traffic from the local test apparatus and send a confirmation transmission to the local test apparatus;
• the local test apparatus being operable to detect the confirmation transmission and transmit to the remote test apparatus further test information comprising a header containing test management information and local-to-remote test traffic for testing the link in the local-to-remote direction;
• the remote test apparatus being operable to receive the further test information and test traffic, analyze the local-to-remote test traffic in accordance with the prescribed test procedure, and, while analyzing of the local-to-remote test traffic is ongoing, transmit to the local test apparatus test information relating to the analysis of the received local-to-remote test traffic, said test information including at least interim test results, and remote-to-local test traffic for analysis by the local test apparatus to test the link in the remote-to-local direction;
• the local test apparatus being further operable, on receipt of the further test information from the remote test apparatus, to extract and analyze the remote-to-local test traffic to determine characteristics of the link in the remote-to-local direction, detect the interim test results from the remote test apparatus;
• and
• consolidate the test results for both directions of the link.

A method of performing bi-directional testing in a link of a communications network using local test apparatus at a local end of the link and remote test apparatus at a remote end of the link, the local test apparatus and the remote test apparatus each being capable of transmitting and receiving in-band test traffic over the link and analyzing received test traffic according to prescribed test procedures to obtain test results, the method comprising the steps of:

• at the local test apparatus, transmitting to the remote test apparatus via the link test information including test management information defining the prescribed test procedures to be carried out upon local-to-remote test traffic to be transmitted by the local test apparatus and received by the remote test apparatus;
• at the remote test apparatus, receiving the test management information and determining the test procedures to be carried out upon subsequently-received local-to-remote test traffic from the local test apparatus and sending a confirmation transmission to the local test apparatus;
• at the local test apparatus, detecting the confirmation transmission and transmitting to the remote test apparatus further test information comprising a header containing test management information and local-to-remote test traffic for testing the link in the local-to-remote direction;
• at the remote test apparatus, receiving the further test information and test traffic, analyzing the local-to-remote test traffic in accordance with the prescribed test procedure, and, while the analyzing of the local-to-remote test traffic is ongoing, transmitting to the local test apparatus test information relating to the analysis of the received local-to-remote test traffic, said information including at least interim test results, and remote-to-local test traffic for analysis by the local test apparatus to test the link in the remote-to-local direction;
• at the local test apparatus, receiving the further test information from the remote test apparatus, extracting and analyzing the remote-to-local test traffic to determine characteristics of the link in the remote-to-local direction, detecting the interim test results from the remote test apparatus;
• and
• consolidating all test results on the local test apparatus.