Network connection system and traffic shaping method for facilitating shaping traffic even in network which accommodates lines based on different protocols

A network connection system for connecting a first communication network and a plurality of user terminals when a second communication network is interposed between said first communication network and said plurality of user terminals, said second communication network employing a second protocol different from a first protocol employed in said first communication network, said system comprising:

• a scheduling apparatus including:
• an overhead amount correction unit for correcting an overhead amount between data conforming to said second protocol and data conforming to said first protocol to convert received information on a rate based on said second protocol to a rate based on said first protocol;
• and
• a scheduler for shaping a transmission rate for the data conforming to said first protocol from said first communication network such that the data conforming to said first protocol is delivered at a transmission rate equal to or lower than said rate calculated by said overhead amount correction unit;
• a protocol converter for converting data conforming to said first protocol after said scheduling apparatus has shaped the transmission rate therefor to data conforming to said second protocol for use in said second network;
• and
• a multiplexer including a current data detector for supplying said scheduling apparatus with said rate information as indicative of a currently set reception rate for said user terminals, said multiplexer being configured to transmit to each of said user terminals the data conforming to said second protocol from said protocol converter or the data conforming to said first protocol after said scheduling apparatus has shaped the transmission rate therefor.