×

Flow and congestion control in packet switched networks

  • US 6,061,330 A
  • Filed: 09/15/1998
  • Issued: 05/09/2000
  • Est. Priority Date: 03/15/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. A method in an ATM system for controlling flows of data cells and flow control management cells from a number of sources to a destination over connections passing a network element, while returning the flow control management cells from the destination via the network element to their respective sources,said network element being exposed to congestion due to contention between the connections, said contention necessitating queuing of the connections,said data cells including lower priority cells and higher priority cells, and said flow control management cells having an explicit rate field for an explicit rate value used to limit a source maximum allowed cell rate to a specific value, and a current cell rate field for receiving said specific value,comprising performing in the network element the steps ofcounting a predetermined number of higher priority cells due to be sent on an output link from the network element to the destination while keeping track of the time interval taken for performing the counting to produce a higher priority cell rate in the form of a ratio between the counted higher priority cells and the time interval,calculating an available rate value for lower priority cells as a difference between a total available link rate value and the higher priority cell rate,establishing a queue length reference forming a desirable queue length,calculating deviations from the available rate value and the queue length reference due to receiving varying amounts of cells on contending connections,calculating a modified explicit rate value as a function of these deviations, andintroducing the modified explicit rate value into the explicit rate field of the backward flow control management cells.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×