has the time
complexity of OðnÞ. These algorithms are successfully
applied in the context of circuit-switching systems, such as
telephony networks, since the established connections usually
last for a relatively long time, e.g., several minutes or
even days, where the time spent on the connection establishment,
say a few seconds, is acceptable.
However, in packet switching systems, the time is usually
slotted, and all the connections are reconfigured in
each time slot. A time slot is usually very short, e.g., 12.5 ns
when the data unit is 64 bytes and the data rate is 40 Gbps
(OC-768/STM-256). Given such a tight slot time, the traditional
GPA algorithms cannot be performed. Some algorithms
are then proposed for the packet switching systems.
Reference