Abstract: A data distribution system capable of suppressing a fall of the efficiency of operation of a network due to repeated data retransmission in the network when distributing a large volume of data from a data distribution server on a data provider side to a data receiver side access server via the network. This data distribution system is comprised by a data distribution server, an access server for transferring intended data to each user, and a network cache apparatus provided in the network and having a cache function unit for temporarily storing the data from the data distribution server and an exchange function unit for routing the stored data to the access server corresponding to the destination user.

Abstract: The present invention relates to holding a call being executed between communication devices in a communication system which has a first function for a holding party of the communication devices to hold the call by transmitting a first request signal to a held party and a second function for the holding party to hold the call by transmitting a second request signal to the held party and receiving a response signal. The holding party transmits the second request signal first and when the response signal is not returned within a given time, transmits the first request signal. A transit device for relaying a call between communication devices, unless detecting the response signal within a given time after relaying the second request signal, transmits the first request signal to the held party, generates the response signal and transmits the generated response signal to the holding party.