S 2.142 Development of a network realisation plan

Initiation responsibility: Head of IT Section, IT Security Management

Implementation responsibility: Administrators

When developing a network realisation plan, it is necessary to determine whether a completely new network configuration, or a modification / extension to an existing configuration is required.

During the configuration of a completely new network, the required steps must be inferred from the network concept which has already been prepared (refer to S 2.141 Development of a network concept). Once planning has been completed, the network is set up by laying the required communications cables, configuring rooms for the technical infrastructure, installing the technical infrastructure itself, integrating the necessary coupling elements (bridges, switches, routers etc.), configuring the network management stations, fitting the terminal devices with corresponding network adapters and configuring these terminal devices.

If an existing network is to be modified or extended, the network concept prepared in accordance with S 2.141 Development of a network concept should be compared with the actual situation as described in S 2.139 Survey of the existing network environment. Based on any resulting differences, a realisation plan for network migration can be outlined, taking into account the above-mentioned measures. Here, it must be noted that the greater the deviation between the network concept and the actual situation, the greater the realisation effort.

Example of migrating from a shared Ethernet to a switched Fast Ethernet

Migration from one network topology to another normally takes place in stages. A migration from a shared Ethernet to a Fast Ethernet with switching technology is outlined as an example in the following. Under real conditions however, the constraints need to be checked thoroughly and a special migration concept needs to be prepared for each individual case.

• Migration step 1

In the first migration step, the existing backbone can be replaced by a Fast Ethernet backbone, or a new one can be installed if necessary. The remaining shared Ethernet segments are connected via the backbone's network components which must accordingly also support Standard Ethernet.

• Migration step 2

Establishment of structured cabling, i.e. a conversion is performed from a Standard Ethernet with breakout cabling to a cabling concept in which every workstation is connected in star configuration to a distributor room without abandoning the topological bus structure.

• Migration step 3

The servers are connected centrally to a switch with Fast Ethernet adapters (installation of a so-called server farm).

• Migration step 4

Migration of the remaining Ethernet segments to a fully switched system. For this purpose, for example, Ethernet switches can be linked to the Fast Ethernet switches of the backbone.

• Migration step 5

Migration of the remaining Ethernet segments to a fully switched system. For this purpose, for example, Ethernet switches can be linked to the fast-Ethernet switches of the backbone.