Summary: The paper analyses the effects of Selfish routing (source & overlay) on an intra-domain
network. Theoretical worst cases have shown that Selfish routing could result in suboptimal
system behavior with serious performance degradation arising out of lack of cooperation
between the sources. This paper tries to quantify the extent of sub-optimality (if it exists?) in
an Internet like environment.
The following observations helps understand what needs to be measured and compared
· Internet has a definite structure to its Traffic demands and topologies - the theoretical worst
cases might not be applicable in these scenarios
· Overlay routing doesn't give full flexibility - the physical network decides the route between
· Horizontal Interactions - overlay traffic (foreground) and the regular (background) traffic
interact and would impact each others performance
· Vertical Interactions - Selfish routing interactions with Traffic engineering. Mismatch of
policies often result in severe performance degradation.
They go on to compare selfish source routing, selfish overlay routing with optimal and
compliant routing and in this process find out that selfish routing doesn't necessarily result in
suboptimal system performance. They go on to observe that selfish routing results in
congestion on certain links.
· Clearly shows the practical applicability of selfish routing, by demonstrating how it need not