setup which is initiated by tcp packets having the syn flag set as is well known in the relevant arts preferably classifier 212 identifies tcp packets comprise data representing a tcp window size for a tcp session according to the status of the syn flag in the tcp packets of course other sorts of tcp packets can comprise data representing a tcp window size for a tcp session embodiments of the present invention employ other well known techniques to identify such tcp packets classifier 212 forwards the identified tcp packets to processor 214 step 304 processor 214 examines the tcp window size in each of the forwarded tcp packets to determine whether the tcp window size should be reduced step 306 preferably the decision whether to reduce the tcp window size of a tcp session is based on 1 the size of the packet buffer and 2 the tcp window sizes for other tcp sessions currently active in router 202 in some embodiments the decision is also based on an estimate of the future addition and tear down of tcp sessions involving router 202 which can be generated based on network history and traffic patterns to support this decision processor 214 maintains a table 216 of tcp window sizes for active tcp sessions in memory 206 each entry in table 216 includes an identifier of a tcp session for example internet protocol ip addresses for the source and or destination network device 104 106 of the tcp session as well as the tcp source and destination port numbers and.