Special Notations for Repetitive Constructs Repetition – A → A | (left recursive), and – A → A | (right recursive) where and are arbitrary strings of terminals and non-terminals, and – In the first rule does not begin with A and
A packet switch consists of a routing engine(table look-up), a switch scheduler, and a switch fabric. The routing engine looks-up the packet address in a routing table and determines which output port to send the packet. Packet is tagged with port number The switch uses the tag to send the packet to the proper output port Eytan Modiano