next up previous
Next: Results Up: The Macramé network testbed Previous: Software

Network topologies

Figure 2 shows how a two dimensional grid network topology can be constructed. Each packet switch has 16 on board connections to traffic nodes and four external connections to each of its four nearest neighbours. A 3-stage folded Clos [7] network is shown in Figure 3.

  
Figure 3: 256 node Clos network  
Figure 2: Architecture of the Macramé testbed  

On the grid topology a deterministic routing algorithm with dimension order routing is used, i.e. packets are sent first in the north/south direction and then in the east/west direction to their respective destinations. This algorithm ensures deadlock-free routing on the grid. Furthermore, grouped adaptive routing is used on parallel links between adjacent routers, i.e. a packet will be sent on the first free link in a group.



Stefan Haas
Thu May 22 14:48:25 MET DST 1997