In these situations, the network is expected to be in good working condition, and monitoring exchanges could probably comfortably work with an unreliable transport protocol. The chance of data loss is small, and probably not a serious problem since the data is unlikely to be so important that it must be reliably delivered. Firefighting is a completely different situation. In this scenario, one or more sites are using management applications to try to locate and fix a network problem. In such circumstances, a reliable protocol is essential.
Events provide yet another bit of complexity.
Events contain useful status information, but experience suggests that this information does not have to be delivered reliably. If the problem is serious enough, it will re-occur and the event will be sent again. Furthermore, events will often be sent to more than one management center, which would appear to preclude the use of connection- oriented, reliable protocols such as TCP for events. It turns out that such a co-existence is feasible, and the authors have made an effort to accomodate it. At the highest level, both CMIP and HEMS perform operations on objects stored in remote entities, and both systems use ASN.1 formatting to represent those objects.