Here we further introduce two variations of BF: BF-delay and
In BF-delay, network delay information is used to
break the tie at step 3, i.e., when multiple nodes have paths to the
incoming client with
the same amount of bandwidth, the client closest to the
requesting client is
BF-delay-approx uses a different bandwidth metric in step 2 and step
3. Instead of the actual available bandwidth , it uses , where is 1
if client has enough bandwidth to support the incoming client
's request, and 0 otherwise.
The delay information is used to break the tie.
Since BF-delay-approx only
needs to test whether a client can admit the incoming client rather
than measure the exact amount of available bandwidth as BF and
BF-delay algorithm do,
the measurement overhead of BF-delay-approx is lower than that of BF and
Hence the joining delay in BF-delay-approx is expected to be small.