A BUFFERED STATISTICAL-DATA FORK

Recently, Cruz (1990) proposed the Statistical Data Fork (SDF) as a mu ltichannel switch supporting trunk groups in a broadband network. Rout ing error for a multichannel switch is the probability that a packet e ntering the switch does not exit the switch on its desired trunk group . This paper studies variations of the basic SDF architecture in which the number of subchannels per link is K greater than or equal to 2. T his effect can be achieved by the inclusion of buffers into the archit ecture or by dilating the links of the switching network. We show that in some cases the routing error for K = 2 is smaller than for K = 1 b y several orders of magnitude. We also consider the problem of assigni ng the output links to the trunk groups to minimize the routing error while constraining the size of each trunk group. Finally, we study the sensitivity of the routing error to changes in traffic rates.