an access server architecture , and methods for use of the architecture , are disclosed . the architecture and methods are designed to increase the scalability of and balance processor load for a network access server device . in this architecture , packet forwarding and packet processing are distributed amongst the cards serving the low - speed access lines , such that each line card is responsible for performing forwarding and packet processing for packets associated with the low - speed ports that line card serves . thus , as the number of line cards expands , forwarding resources are expanded in at least rough proportion . the nas route switch controller , as well as the high - speed ports used to access the network , are largely relieved of packet processing tasks for traffic passing through the server . the egress port uses a distribution engine that performs a cursory examination on one or more header fields on packets received at the high - speed interface - comprehending only enough information to allow each packet to be distributed to the appropriate line card for full packet processing . the route switch controller updates the routing information needed by each distribution or forwarding engine , and is largely uninvolved in the processing of individual packets .