With two full duplex 1.2 Gbps ATM ports, the APIC can be easily inserted in a link and can thus, efficiently snoop traffic as the ATM cells move from the input to the output port. The APIC can sustain an aggregate bi-directional data rate of 2.4 Gbps. The endsystem probe comprises of protocol probe functions that are embedded within the main data processing path of the protocol. Once activated, a probe function is called for each packet, and if the packet belongs to a connection or flow of interest, selected parameters of the packet and of the connection state are retrieved and written to a kernel trace log, which is a circular buffer maintained in wired down memory. Software Management Agents Software network management agents in our proposed system are built atop network probes and used to track event flows, as well as classify and report events of interest to NOCs.
Agents help NOCs maintain the reliability and quality of service for the overall system.
In conventional low-speed networks this is typically accomplished by having NOCs periodically poll certain attributes of objects managed by agents. Polling is used to monitor the current state of the network elements and to take corrective action when problems are detected. However, selecting an appropriate polling interval is difficult. Polling too often creates excessive network and system load, whereas polling too infrequently prevents NOCs from detecting and reacting to serious system problems. In gigabit networks, polling is even more problematic because the tremendous volume of events can trigger an enormous number of state changes between polling intervals.