iation function is located between the managed network and the central manager. It mediates on (or translates) the interchanged management information. It works under the selected TM management/agent standard towards the central manager, and under the corresponding proprietary manage- ment system towards the network elements. To overcome TMN (ITU-T) and SNMP (Internet) integration drawbacks the introduc- tion of management gateways, able to handle SMNP towards the network element and TMN towards the central general manager or vice versa, seems to be a solution. The desired solution will very likely require the interconnection of management planes among different operators. This is a new trend emerging from the new technological and business environment but still at preliminary phases of R&D. Conceptually it poses problems, similar to those treated for the traffic plane interconnection. The addressed issues are: Determination of the management point of interconnection (POI) Admission policies Charges distribution Interfaces and protocols O&M responsibilities See also Figure 16.1. Determination of the management POI. Interconnection interfaces will probably be management gateways. Their location in the network will be a decision to make. Admission policies. Determination of which requests or activities from other manage- ment systems will be accepted, and what kind of screening, if any, shall be made on output data. Determination of who will be authorized to program and decide this. Charges distribution. The distribution of cost incurred in the development and adap- tation of each management system or a general integrated ssystem, if available. Interfaces and protocols. Interworking interfaces (how will the management gateways be?) and protocols for management planes cooperation. Telecom Management - Operations 3rd party Systems Service vendor application provider design Network Carrier Elements downtime: equipment operator vendor Final Service downtime: 4% Network Access equipment network End user vendor operator 