To efficiently confirm end-to-end mutual understanding between in-house apparatuses.

A loop back test system executes a loop back test from a first in-house apparatus to a second in-house apparatus through a communication network. The first in-house apparatus generates a test frame by setting a transmitting source address as the address of the first in-house apparatus and setting a transmitting destination address as the address of the second in-house apparatus and sends the test frame to the communication network and the second in-house apparatus receives the test frame sent from the first in-house apparatus and sends the test frame by setting the transmitting source address as the address of the second in-house apparatus and setting the transmitting destination address as the address of the first in-house apparatus to the communication network. Then the first in-house apparatus receives the test frame sent from the second in-house apparatus and transmits the test frame to a center apparatus as a test result and the center apparatus receives the test frame as the test result.

COPYRIGHT: (C)2006,JPO&NCIPI