In the University of Münster the “Centre for Information Processing”, or “Zentrum für Informationsverarbeitung” (ZIV), has a key role as the Network Operation Centre (NOC) not only for the University itself, but also other facilities, e.g. the medical hospital and other educational institutes in Münster. That said, while ZIV is part of the university, it operates the network for several parties and is a kind of provider to multiple users. Therefore the network is not just a core network, but is more complex as it has several core networks and a transit network between them. Some smaller core networks connected to the transit network are not operated by the ZIV-NOC.

Figure 13-1 gives a rough overview of the current IPv4 network. All the routers shown are Cisco Catalyst 6509’s with different kinds of engines (SUP2 or SUP720). Usually the connections shown are aggregated Gigabit Ethernet or 10Gigabit Ethernet connections. Redundancy is a key part of the whole network infrastructure and you will find redundant routers and structures in every core part of the network.

At the top of Figure 13-1 you see the transit routers ISPA and ISPB. One of them is connected to our upstream provider DFN. The network infrastructure below these two routers is the idealised form of the core network of the University. UNIA and UNIB act as border routers with redundant connections to the transit routers and likewise as the core routers of the internal network.