  This paper presents a new analytical model for calculating burst loss rate
(BLR) in a slotted optical burst switched network. The analytical result leads
to a framework which provides guidelines for optical burst switched networks.
Wavelength converter is used for burst contention resolution. The effect of
several design parameters such as burst arrival probability, wavelength
conversion capability, number of slots per burst and number of wavelengths is
incorporated on the above performance measure. We also extend the analytical
result of BLR for different types of service classes where each service class
has a reserved number of wavelengths in a network with fixed number of
wavelengths. We also introduce an algorithm to calculate the resultant number
of wavelength for each service classes depending on the various scenarios.
