l technical plan (among other views) Security Content Attacks anywhere! Security Added Service layer capabilities value Service Control management Service Mobility Charging Signalling manage- Attacks! Switching Dimensioning Numbering routing (control and Availability connectivity Synchronization Connectivity resources) resources Network management Traffic Frequency Transmission Organization Figure 6.11 Fundamental technical plans are target for attacks The IP control plane: the attacks can hit the addressing functions. The domain name system (DNS) is the directory service inside the Internet. It is the DNS that translates a WWW or IP address (for example 10.30.100.45). Suppose that an intruder wants manipulate the DNS database. If possible, then a user may think that he is communicating with his bank, while in fact he is communicating with the intruder system (which could be a copy of the bank's home page). In this way the intruder can get hold of, for example, bank account numbers and passwords. Other attacks can hit the routers, whether seen as control or connectivity elements. The routing plan uses routing tables in the routers for controlling traffic flows and making decisions based on packet content and configuration. The routers are accessible through the network and are therefore often targeted by attackers trying to hack their way in. If an attacker can control the traffic flow in the network, he can get his own packets to any destination (misrouting). The charging system is of course interesting for hackers, as well. The signalling systems are the nerve systems of the communication. Protection of signalling (SIP, SDP) traffic has priority. Regarding the connectivity layer, transmission is a weak part for eavesdropping radio systems. At low level, hardware such as switches and relays might be destroyed. Electronic attacks can make the network stop working. Wires could be cut. Fire and water are other risks. Attacks on the management part may be more severe than others. Management security is of particular