Vorlage 3b

CSP’s area of responsibility LEMF site 1 non- LEMF coincident LI-HP MD Access Line NT GW LE DN-HP MD hosting facility DN provider DN provider NT facility facility ISDN-DN provider’s area of responsibility LEMF site 2 MD DN provider DN provider NT facility facility DN-HP GW LE NT Access Line MD LI-HP LEMF

non-

MD hosting facility PTSS’ area of coincident responsibility Figure 8 Handover points and areas of responsibility in the ISDN delivery network

Note: Figure 8 contains no guidelines on the internal connections in PTSS' area of responsibility, e.g. concerning overflow traffic between the two LEMF sites.

7.2.1 Security aspects of the CS DN

The bilateral connection agreements shall define specific protective measures for the following points:

 Confidentiality (including data protection)

 Authentication

 Authorised access availability (i.e. no refusal of authorised access to network

elements, saved information, information flows, services and applications but not in terms of general availability)

 Data integrity

 Non-repudiation (incontestability of receipt of the data, similar to a registered letter with acknowledgment of receipt)

Figure 9 shows the three functional layers “Cable channels/cabling”, “SS7 Network” and “Network layer”. At the interface between the CSP and the ISDN Delivery Network provider (generally several E1), the “Circuit Switched Content of Communication” (CS CC) traffic is mixed with other interconnect traffic. In the network of the ISDN Delivery Network provider, the payload traffic and the signalling traffic are separated and the CS CC traffic is also mixed with other traffic. In the Primary Rate Accesses (PRA) to the LEMF, only the CS CC traffic is conveyed. CS CC does not contain any identifiers allowing for identification of the target using a telephone directory; only in the Calling Party Subaddress when setting up a CC link there is the parameter “Lawful Interception Identifier” (LIID) which provides a correlation to the target as a unique “order number”. This relationship is treated as confidential between the CSP and the PTSS. Identification of the target would otherwise only be possible by way of voice recognition of the CS CC.