Data communications networks, systems, methods and apparatus

Abstract

A data communications network comprises a plurality of terminals and a main server adapted to manage selective retrieval of data from a first server by at least one target terminal. Some or all of the terminals are adapted to act as relay servers for serving data retrieved from the first server to at least one target terminal. The network includes a network information database and the main server selects at least one target terminal to act as a relay server for serving data to other target terminals on the basis of terminal performance information stored in the network information database. Terminals acting as relay servers also select further downstream target terminals to act as further relay servers on the basis of the relative performances of the further target terminals. The load on the main server is thus distributed among all of the relay servers, providing improved network performance.

1 . A data communications network comprising:
 a plurality of terminals;   a main server adapted to manage selective retrieval of data from a first server by at least one target terminal selected from said plurality of terminals; wherein at least some of the terminals are adapted to act as relay servers for serving data retrieved from said first server to at least one target terminal; wherein the main server is adapted to send transport requests direct to at least one first target terminal, and the first target terminal is adapted to act as a relay server;   wherein said transport requests include details of data to be retrieved, the address of the first server from which the data is to be requested by the first target terminal; and the address of at least one second target terminal to which the data retrieved from the first server is to be relayed by the first target terminal.   
     
     
         2 . A network as claimed in  claim 1 , wherein terminals adapted to act as relay servers are adapted to modify transport requests received from the main server or from other relay servers and to transmit the modified transport request to selected target terminals from a set of target terminals identified in the transport request, wherein the modified transport request identifies the terminal transmitting the modified transport request as the server from which the recipients of the modified transport request should request the data. 
     
     
         3 . A network as claimed in  claim 1 , further including a network information database, wherein the main server is adapted to select at least one first target terminal to act as a relay server for serving data retrieved from said first server to at least one second target terminal on the basis of terminal performance information stored in said network information database. 
     
     
         4 . A network as claimed in  claim 3 , wherein the modified transport request further includes addresses of further target terminals for which the recipient of the modified transport request is to act as a relay server. 
     
     
         5 . A network as claimed in  claim 3 , wherein the main server is adapted to send transport requests direct to at least one first target terminal, said transport requests including:
 details of data to be retrieved and the address of the first server from which the data is to be requested by the first target terminal; and   addresses of a plurality of further target terminals to which the data retrieved from the first server is to be relayed by the first target terminal; the transport request further indicating the relative performances of the further target terminals based on the terminal performance information stored in said network information database.   
     
     
         6 . A network as claimed in  claim 5 , wherein terminals acting as relay servers are adapted to select further downstream target terminals to act as further relay servers on the basis of the relative performances of the further target terminals indicated in said transport request. 
     
     
         7 . A network as claimed in  claim 6 , wherein the relative performances of said further relay servers are indicated in said transport request by ranking the addresses of the further target terminals in an ordered list. 
     
     
         8 . A network as claimed in  claim 1 , wherein the first server is the main server. 
     
     
         9 . A network as claimed in  claim 1 , wherein the main server is distinct from the first server 
     
     
         10 . A network as claimed in  claim 1 , wherein the first server is a terminal adapted to act as a relay server. 
     
     
         11 . A network as claimed in  claim 1 , wherein data to be retrieved by said target terminals is divided into a series of packets for transmission to said target terminals, and each of said terminals is adapted to communicate directly with said main server to acknowledge receipt of the last packet of a series routed thereto. 
     
     
         12 . A network as claimed in  claim 1 , in which the main server is configured to monitor response times of terminals in the network and in which terminals are selected to act as relay servers for particular data transfers on the basis of their relative response times. 
     
     
         13 . A method of data communications by a network having a plurality of terminals and a main server adapted to manage selective retrieval of data from a first server by at least one target terminal selected from said plurality of terminals; said method comprising:
 operating at least some of said terminals as relay servers for serving data retrieved from said first server to at least one target terminal,   sending transport requests from the main server direct to at least one first target terminal,   operating the first target terminal as a relay server, and   wherein said transport requests include details of data to be retrieved, the address of the first server from which the data is to be requested by the first target terminal and the address of at least one second target terminal to which the data retrieved from the first server is to be relayed by the first target terminal.   
     
     
         14 . A method as claimed in  claim 13 , further comprising operating terminals adapted to act as relay servers to modify transport requests received from the main server or from other relay servers and to transmit the modified transport request to selected target terminals from a set of target terminals identified in the transport request, the modified transport request identifying the terminal transmitting the modified transport request as the server from which the recipients of the modified transport request should request the data. 
     
     
         15 . A method as claimed in  claim 14 , wherein the modified transport request further includes addresses of further target terminals for which the recipient of the modified transport request is to act as a relay server. 
     
     
         16 . A method as claimed in  claim 13 , wherein the network further includes a network information database, the method including operating the main server to select at least one first target terminal to act as a relay server for serving data retrieved from said first server to at least one second target terminal on the basis of terminal performance information stored in said network information database. 
     
     
         17 . A method as claimed in  claim 16 , further comprising operating the main server to send transport requests direct to at least one first target terminal, said transport requests including:
 details of data to be retrieved and the address of the first server from which the data is to be requested by the first target terminal,   addresses of a plurality of further target terminals to which the data retrieved from the first server is to be relayed by the first target terminal, and   relative performances of the further target terminals based on the terminal performance information stored in said network information database.   
     
     
         18 . A method as claimed in  claim 17 , further comprising operating terminals acting as relay servers to select further downstream target terminals to act as further relay servers on the basis of the relative performances of the further target terminals indicated in said transport request. 
     
     
         19 . A method as claimed in  claim 17 , further comprising indicating the relative performances of said further relay servers in said transport request by ranking the addresses of the further target terminals in an ordered list. 
     
     
         20 . A method as claimed in  claim 13 , including operating the main server to monitor the response times of terminals in the network and selecting terminals to act as relay servers for particular data transfers on the basis of their relative response times.