ters basically are related to the type of system hardware that is being used, i.e. whether it is ETSI-based (E1) or ANSI-based (T1), etc. PDH/SDH interface parameters are related to the configuration of the PDH or SDH terminals that are being used. These also include some testing parameters apart from the ones needed to configure these terminals. As the structure 3G TRANSMISSION NETWORK PLANNING AND OPTIMISATION of SDH is more complicated than PDH, more parameters are required for its configuration, related to the physical, multiplexer, regenerator and virtual container sections. ATM Termination/Cross-connection Parameters This constitutes the largest group of parameters to be configured. It includes parameters that are required for the identification and termination of virtual channels, virtual paths and their cross-connections. Also, parameters describing the type of traffic that is being carried by these virtual channels and paths are configured. The 'rules' set out by the ATM forum or ITU recommendation for virtual channel and path identifiers should be followed, such as the number of VCIs reserved or the maximum/minimum number of bits that can be used for VCI/VPI. Every vendor/operator follows its own numbering scheme that should be respected. Cross-connection in an ATM network can be at a physical level, VP level and VC level. (In GSM transmission networks, the cross-connections take place only at the physical level.) If expansion is expected soon, VP-level cross-connections should be planned as only few re-configurations are required even when new features are added. VC-level cross- connection are quite complex especially if only one VP is being used. One example is shown in Figure 8.11. ATM Cross-Connect Unit PDH/SDH User Plane Traffic Signalling Router Management Port Figure 8.11 ATM terminations and cross-connections IP Addressing Parameters Both private and public IP addresses should be clearly defined. Private IP addresses are the ones that are used for internal communications and cannot be changed, w