Vadapalli and Srimani[2] have proposed a new family of Cayley graph interconnection networks of constant degree four. Our comments show that their proposed graph is not new but is the same as the wrap-around butterfly graph. The structural kinship of the proposed graph with the de Bruijn graph is also discussed.

Preparata and Vuillemin proposed the cube-connected cycles (CCC) in 1981, and in the same paper gave an asymptotically-optimal layout scheme for the CCC. While all the known optimal layouts of the CCC, including the Preparata–Vuillemin layout, have long wires, we give a new layout scheme which has no long wires while keeping the asymptotically-optimal area. Hence, we can conclude that the CCC can be laid out optimally (within a constant factor) both in area and in wire length. We also show how large a constant-factor blow-up in area is needed in order not to produce any long wire in the layout.

A fundamental problem that confronts structured peer-topeer system that use DHT technologies to map data onto nodes is the performance of the network under the circumstance that a large percentage of nodes join and fail frequently and simultaneously. A careful examination of some typical peer-to-peer networks will contribute a lot to choosing and using certain kind of topology in special applications. This paper analyzes the performance of Chord[7] and Koorde[2], and find out the crash point of each network through the simulation experiment.

We propose a simple distance-vector protocol for routing in networks having unidirectional links. The protocol can be seen as an adaptation for these networks of the strategy as used in the popular RIP protocol. The protocol comprises two main algorithms, one for collecting "from" information, and the other one for generating and propagating "to" information. Like the RIP protocol, this one can handle dynamic changes and tolerate node and link failures in the network.