Embedded systems do not benefit from strong memory protection, because they are designed to minimize cost. At the same time, there is increasing pressure to connect embedded devices to the internet, where their vulnerable nature makes them routinely subject to compromise. This fundamental tension leads to the current status-quo where exploitable devices put individuals and critical infrastructure at risk.

The ubiquity of embedded devices is apparent. The desire for increased functionality and connectivity drives ever larger software stacks, with components from multiple vendors and entities. These stacks should be replete with isolation and memory safety technologies, but existing solutions impinge upon development, unit cost, power, scalability, and/or real-time constraints, limiting their adoption and production-grade deployments. As memory safety vulnerabilities mount, the situation is clearly not tenable and a new approach is needed.

In ATM networks, connection admission control (CAC) has been recognized as one of the most important means to provide satisfactory quality of service (QoS) and protect the network from congestion, especially for supporting real-time services such as voice and video. An efficient CAC strategy, which can both guarantee the QoS of admitted connections and achieve good resource utilization, then becomes a crucial issue for ATM network providers. The concept of a user-network traffic contract has been introduced by the ATM Forum. Starting from this point, we propose a measurement-based CAC strategy. We first discuss how to obtain an accurate description (traffic parameters) of user traffic by using on-line measurement in conjunction with dynamic renegotiation. The results show that the proposed strategy is reliable and simple to implement. We then move on to examine the possibility and methodology for exploiting the effect of statistical multiplexing in resource allocation to achieve higher network resource utilization.