A method and apparatus for buffering data units in a communication switch that allows for configurable monitoring of the buffer contents is presented. Such an apparatus includes a context table that stores a plurality of independent group identifiers for each connection. Although the group identifiers may include a partition group identifier and a loss group identifier that is dependent on the partition group identifier, additional group identifiers are included in the context table for each connection that are independent of other group identifiers in the context table. Such a context table may be dynamically reconfigured in order to group connections for buffer monitoring operations related to congestion detection, traffic shaping, and data admission with respect to buffering. When a data unit is received corresponding to a particular connection, the context table is referenced to retrieve the set of group identifiers corresponding to that connection. As a cell is stored in the buffer, count values corresponding to at least some of the group identifiers included in the set of group identifiers for that connection are incremented. Similarly, when data is dequeued from the buffer for forwarding, the set of group identifiers for that particular data unit is determined and the counters corresponding to at least some of those groups are decremented. As such, the count value corresponding to each of the groups can be referenced to determine the number of data units corresponding to that group that are currently stored within the buffer.