nd and corporate networks there were forecasts with more than 100 % yearly increases during the first years of the new millennium. A new managed Assume: 2,5 Gbit/s per lightwave 200 Iw per fibre 10 14 bit/s (100 Tbit/s) 200 fibres per cable Assume: 10 Mbit/s/user 10 million users 100 Tbit/s cable simultaneously! Figure 12.5 Potential capacity of one fibre cable Point-to-point to enhance capacity and solve fibre exhaust Point-to-point with traffic protection features added Optical ADM ring topologies More advanced-wavelength reuse, switching capabilities, i.e optical networking Figure 12.6 Development within the area of fibre technique - a new managed network level appears, with optical switches/cross-connects Understanding Changing Telecommunications - Building a Successful Telecom Business FSC link(s) PSC links TDM links LSC links Fibre OC-48 OC-192 100 M Figure 12.7 The available capabilities: fibre switching capability FSC, lambda light-wave (wave- length) switching capability LSC, time division multiplexing TDM and packet switching capability network level appeared with a tremendous capacity, thanks to further development of opti- cal networking of the wavelength division technique and higher speeds. The result was a significant and fast extension of the backbone networks, bringing lots of over-capacity when the forecasts failed. The overall capabilities are illustrated by Figure 12.7. OC-192 (OC = optical carrier) has a capacity of 10 GBit/s and the OC-48 of 2.5 GBit/s. OC-192 is an established capacity in backbone networks. Certainly, capacity is not the problem, rather the handling of the resources, that is control and management. 12.4 CONTROL FUNCTIONS IN THE PACKET BACKBONE 12.4.1 OVERVIEW Figure 12.8 shows that the control functions are distributed to many layers, including the connectivity layer. 12.4.2 CONTROL SPLIT Figure 12.9 shows an example of a border area functionality split between backbone connectivity control and call control. The exemplified standard (BICC) is described in Chapter 14. In the