A communication conditions determination system having a determination apparatus that determines communication conditions of a first communication network and a second communication network which are connected by a connection apparatus, the determination apparatus comprising a controller capable of
- detecting a packet passed through the second communication network;
- determining whether or not the detect packet is a packet sent to the second communication network from the connection apparatus;
- determining, in the case that the packet is determined to be a packet sent to the second communication network from the connection apparatus, whether a source apparatus of the packet is the connection apparatus or an apparatus other than the connection apparatus;
- individually summarizing packets whose respective source apparatuses are determined to be the connection apparatus and packets whose respective source apparatuses are determined to be an apparatus other than the connection apparatus;
- and
- comparing individual summarized results and determining the communication conditions of the first communication network and the second communication network.