Patent ID: 6381214
Filing Date: 2002-04-30
Classification: H04L,H04Q

Abstract:
A method of monitoring information communicated over a network to determine conformance of the communicated information with a traffic contract, the information arranged as cells from a plurality of virtual channels, comprising the steps of:storing, in a memory, and for each of the plurality of channels, a difference field value corresponding to a time after which a next arriving cell of the channel is conforming, and an increment value corresponding to a cell rate for the channel; digitally monitoring a global time using a number of bits larger than a number of bits with which the difference field value is stored in the memory for each of the plurality of channels; for each of the plurality of channels, periodically comparing a least significant portion of the global time to the difference field value and, responsive to the least significant portion of the global time exceeding the difference field value, resetting the difference field value for the channel; and responsive to receiving a cell for a channel at an arrival time, performing the steps of: first comparing a least significant portion of the arrival time of the received cell to the difference field value for the channel; responsive to the comparing step determining that the least significant portion of the arrival time is earlier than the difference field value, comparing a difference between the least significant portion of the arrival time and the difference field value to the increment value for the channel; responsive to the difference comparing step determining that the difference does not exceed the increment value, issuing a signal indicating that the cell is nonconforming; and responsive to either the comparing step determining that the least significant portion of the arrival time is not earlier than the difference field value or to the difference comparing step determining that the difference exceeds the increment value, updating the difference field value for the channel.