Rate control in transmission of packet data over an ATM network

Apparatus for controlling data transmission over a high-speed network, comprising:

• an input packet interface, configured to receive over a packet link at a variable input data rate a succession of packets containing data, each packet in the succession having a respective, non-uniform packet size;
• an output interface to the network, configured to transmit the data over the high-speed network at either a peak data transmission rate predetermined by the network or at a rate no greater than a sustainable data transmission rate predetermined by the network, which sustainable transmission rate is less than the peak transmission rate;
• and
• a processor, coupled between the input and output interfaces and adapted to control the transmission rate of the data contained in each of the data packets in the succession by comparing the respective packet size to an allocated transmission credit, such that if the allocated credit is sufficient, compared to the respective packet size, the packet is transmitted over the network at the peak data transmission rate, while if the allocated credit is insufficient, compared to the respective packet size, at least a portion of the packet is transmitted at the rate no greater than the sustainable data transmission rate.