A method of providing performance trend information from a device in a
packet-switched network to a network management station comprises
maintaining in the device one or more state variables that store values
associated with data processing functions of the device; storing in the
device a trend indicator value and a trend tendency value, both
associated with a particular state variable among the state variables;
periodically sampling the particular state variable to obtain one or more
sampled values; determining and updating the trend indicator value with a
direction of change in the sampled values of the particular state
variable over a particular time; determining and updating the trend
tendency value with a rate of change in the one or more sampled values of
the particular state variable over the particular time; and sending the
trend indicator value and the trend tendency value to the network
management station.