The QPSX MAN

The authors discuss QPSX (queued packet and synchronous switch), a distributed switch/network that will fulfil the requirements of a public metropolitan area network (MAN) and has wide telephone industry support. The dual-bus architecture of QPSX and its extension, the looped-bus architecture, are described. The architecture of the public MAN is examined, particularly with respect to QPSX as a proposal for IEE P802.6 standardization. The distributed queueing protocol, segmentation and reassembly scheme, and reliability features of the QPSX network are discussed.<>