A bounded-hop-count deflection scheme for Manhattan-street networks

We present a deflection method suitable for Manhattan-street networks (MSN), which, without dropping packets, limits the number of hops travelled by a packet on its way from source to destination. The proposed routing scheme is intended for bidirectional networks-with four incoming and four outgoing links per switch. In terms of average performance measures, our method performs no worse than the best local routing schemes, when the offered load is light or moderate. Unlike other deflection schemes proposed for MSN, our method is inherently asynchronous. This simplifies the switch design and eliminates some problems with the original synchronous approach, like the need to account for slight discrepancies in transmission rates of different switches.