two labels one for each direction clockwise cw and anti clockwise or counter clockwise ccw furthermore as will be explained in further detail below a packet within the ring label is sent round the ring until the time to live ttl expires furthermore a breakout from the ring transport is checked at each hop in the following the steps 1 5 shown in fig7 will be explained in more detail in step 1 a packet enters the ring on an internal port the domain controlled by a central control entity such as ce 200 of fig3 covers the h ran so the ring and the l ran upto to l ran leave the connection between the h ran and the core network is an external port as packets leave the ce domain the connection l ran u2014 h ran is within the ce domain so it is an internal port within the ce domain the packet carries a transport label identifying the destination external port this transport label was added at the external port when entering the ce domain so for packets received in step 1 by fe 3 13 the transport lable was added at the l ran leave where the packet was received form externally the transport label is indicated by reference numeral 71 in fig7 any data packet detected at.