In IEEE International Conference on Telecommunications 2001


Best Effort Differentiated Services: Trade-off Service Differentiation
for Elastic Applications

Victor Firoiu, Xiaohui Zhang, Yang Guo


ABSTRACT

We propose an architecture and several mechanisms for providing ``Best
Effort Differentiated Services'' (BEDS), a set of services similar to
Best Effort in that the packet delay and drop probability depend on
the network conditions, but with the added feature of providing a
tradeoff diferentiation in delay and drop probability between the
services in this set.

This proposal starts from the observation that a single Best Effort
service does not fit the needs of all types of elastic applications.
In our proposal, the ``loss-conservative'' service has smaller packet
loss probability but larger delay than the ``delay-conservative'' one.
The former is suited for file transfer applications, whereas VoIP can
significantly benefit from the delay-conservative service.

We provide experimental results that confirm our models' predictions
that file and web transfer and interactive voice applications can
simultaneously benefit from this set of services.  The experiments
were conducted using networks of Nortel routers and switches
implementing our proposed mechanisms.