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% Globally Distributed Content (Using BGP to Take Over the World)
% Paper based on work on Super Sparrow - http://superpsparrow.org/
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% November 2000
% Copyright (C) 2000 Horms <horms@vergenet.net>
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\section{Conclusion}



When implementing Global Load Balancing there is a need to take into
account factors that are not apparent when load balancing traffic on
a LAN. In particular there is a need to be completely independent of other
sites. For this reasons methods such as DNS and HTTP~Redirection are
attractive for directing clients. This is in direct contrast to local
load balancing where methods such as Layer~4~Switching offer superior
control of traffic. 

The BGP-based algorithm discussed provides a powerful mechanism for
determining the network-wise POP for a client. It does not, however, take
into account the relative capacity or load of the POPs that traffic is
being directed to. The assumption made is that each POP has sufficient
capacity to cope with the traffic that it is likely to receive. For this
assumption to hold, local load balancing may need to be deployed at each
POP. The Super~Sparrow implementation has been designed with this in mind
and will work with local load balancing technologies such as
layer~4~switching technology.  In particular, Super~Sparrow is designed to
work in conjunction with Ultra~Monkey\cite{ultra_monkey} which utilises the
Linux~Virtual~Server to effect layer~4~switching.

It is anticipated that in the future the implementation of Super~Sparrow
will be expanded to allow other, non BGP-based algorithms that may take
into account factors such as POP capacity and load.  Ideally an algorithm
that combines capacity and load information with BGP would provide a very
flexible solution.
