fy our service network from Fig. 6.7 to the model in Fig. 6.12. controllers AccRoute CoreRoute Controller Manager Manager Controller Connection Resource System complete information partial information Fig. 6.12 Service resource model information distributed to service objects The model shows my decisions in this respect; I decided to let the TEPC be responsible for the TNW states, CNPC for CNW, SW1 and SW2 states, and the access route manager and core route manager for the AR and CR states respec- tively. How much of the complete models are covered by the partial models depends on which operations are defined for each model, see Sect. 6.2.3. Note that, if the provider alone is responsible for the service state space in a service relation, misbehaving users cannot corrupt the system since the provider is expected to refuse to execute operations in erroneous resource states. This approach might, however, be too slow and costly in demanding real-time applica- tions. If the responsibility is shared or the user alone takes that responsibility, a 6.2 A Service Network Modelling Case more efficient system is achieved, but a misbehaving user can cause serious dam- age to the integrity of the system. Therefore, the responsibility for sharing the state space is shared, is a very important design decision, which has must be considered for every service relation in the service network model. When designing the service network of Fig. 6.12, I decided that the CNPC should be designed as a highly reliable and stable object (an entity of a telecom platform), and could therefore take responsibility for the SW1 and SW2 models. This implies that switches with small processing power can be used, and that short setup times for switch paths can be expected. On the other hand, I did not really trust the TEPC, realizing that the functionality of this object is in constant change, due to new and modified teleservices. Therefore, I let the CNPC alone take respon- sibility for the CNW. 6.2.3 Operations Service resource models give resource