EXP_MULT_04
===========

Objective: Test re-configuration to use a new path (change of locators) for UDP echo application traffic.

Experiment: With all the multihoming functionalities enabled, start the echo UDP application, create a simulated path failure (in the path used by the traffic of the application), and check that the traffic flow continues in the new path (packets can be captured to check new locators, echo application working again (ECHO messages received).

Result: Succeed

Setup: Two OneLab nodes participate in the experiment. One (onelab5.uc3m) placed at UC3M premises, and with one interface with two IP addresses: 163.117.140.167 and 163.117.140.62. The other (onelab2.ucl) placed at UCL premises and with two interfaces with addresses 130.104.72.201 and 130.104.72.206. 

Files:

**  EXP_MULT_04/capture_udpecho_remote_filtered_onelab2.info.ucl.ac.be.pcap and
EXP_MULT_04/capture_udpecho_remote_filtered_onelab5.it.uc3m.es.pcap

These files show the captured traffic in UCL and UC3M during the experiment. For improving clarity only data packets in one direction are shown (the echo replies). The UDP application sends 20 packets, at one second intervals, with the text "text1 without failure" using path (130.104.72.201, 163.117.140.167). Packets go through without problems (the echo replies are shown in the captured traffic). Note that after the 20th message a REAP message is sent (UDP source and destination port 12345), this is the keepalive message sent by the last side receiving a packet without packets to send. Then a new text in entered in the UDP echo application "test2 with failure" (second 45 of the experiment). A simulated command is issued, so packets stop flowing after second 47. REAP messages are exchange looking for an available path. The probes using the path defined by addresses (130.104.72.206, 163.117.140.62) go through and the communication continues in the new path (second 56 of the experiment).

**  EXP_MULT_04/udpecho_client_at_uc3m.png

It shows the screen of the execution of the UDP client at onelab5@uc3m. First, test 1 completes with success. Then test 2 starts and some udp reply messages are lost due to the path failure, but the communication is recovered thanks to the multihoming component operation.