In this paper we compare two approaches for lossbased overload control mechanisms in signaling system with SIP protocol, hop-by-hop and end-to-end. Both discussed mechanisms are based on using a simple non-preemptive priority queueing scheme in SIP server. The effectiveness of both approaches is compared with the system with no overload control. The effectiveness of the solution is measured by ...

We consider a two-class M " A2 IMI'11 preemptive priority queue in which there are two essential on-line decisions that have to be taken. The first is the decision to either accept or reject new type-lor type-2 jobs. The second is the decision to abort jobs, i.e., to remove any type-lor type-2 jobs from the system. We show that there exist optimal threshold policies for these two types of decis...

We suggest that satisfactory statistical performance guarantees for streaming flows can be fulfilled when their packets receive expedited forwarding in non-preemptive priority queues. This relies on the conjecture that jitter remains negligible in the network such that performance measures can be bounded by assuming flows constitute Poisson arrival processes of MTU sized packets. We provide ana...

CPU time spent on switching between concurrent tasks is a pure operating system overhead. This paper describes a technique to reduce the number of context switches caused by task synchronization. Our protocol is applicable to both non-real-time and real-time systems that use preemptive priority scheduling with binary semaphores to enforce mutual exclusion. The protocol does not affect task comp...

The article presents a diffusion approximation model applied to investigate the behavior of priority queues. We discusses the use of the diffusion approximation in transient analysis of queueing models in the case of a single station and of a queueing network presenting the solutions. We emphasize the numerical aspect of the solution and analyze the errors. In classical queuing theory, the anal...

In this paper, we propose an analytical model for integrated real-time and non-real-time service in a wireless mobile network with priority reservation and preemptive priority handoff schemes. We categorize the service calls into four different types, namely, real-time and non-real-time service originating calls, and real-time and non real-time handoff service request calls. Accordingly, the ch...

Fixed-task-priority (FTP) scheduling and earliest-deadline-first (EDF) scheduling policies are alike in fixing the priority of each job of a task at the time the job is released. This common feature of FTP and EDF scheduling permits a unified analysis of scheduling failures, to derive new sufficient tests for meeting all deadlines of a set of independent sporadic tasks under a global preemptive...

In this paper, a new preemption policy is proposed and complemented with an adaptive scheme that aims to minimize rerouting. The preemption policy combines the three main optimization criteria: number of LSPs to be preempted, priority of LSPs to be preempted, and amount of bandwidth to be preempted. The preemption policy is complemented by an adaptive scheme that selects LSPs with lower priorit...

Current schedulability analyses for preemptive systems consider cache behaviour by adding preemption caused cache reload costs. Thereby, they ignore the fact that delays due to cache misses often have a reduced impact because of pipeline effects. In this paper, these methods are called isolated. Pipeline-related preemption costs are not considered at all in current schedulability analyses. This...