3 research outputs found
Dynamic Bandwidth Allocation in ATM Networks
Today's new applications such as World Wide Web, video conferencing and
multimedia have introduced a large amount of traffic into the network. Additionally
new applications are also heading towards real time process. Instant access to the
network, greater level of performances and higher degree of satisfaction has
become the main concerns of users using these new applications. Although current
transmission mediums have advanced in capacity through means such as optical
fiber and Gigabit Ethernet, future and unknown new services tend to consume up
the available bandwidth. ATM network is the new technology used to support a
wide variety of services including data, voice, video and most possibly other future
applications. Its flexibility, efficiency and high throughput have gained popularity
but with greater complexity due to different approaches in handling different type
of services.A high-speed network such as ATM networks must have an effective traffic
management scheme in order to gain high data throughput with the least cost of
operation. Thus, simulation and modeling are the effective methods used to design
the trade-off between network parameters and their performances. Effective sharing
of network resources such as bandwidth and buffer are studied through the dynamic
allocation method. Static allocation scheme has been proven inefficient to provide
high resources utilization as can be seen in STM networks compared to A TM
networks. However, ATM networks should provide different dynamic allocation
methods according to its different services and traffic characteristics. Four dynamic
allocation strategies have been designed, evaluated and compared for their
performances. They are called Static Bandwidth Allocation, Bandwidth Allocated
Proportional to Expected Queue Length, Bandwidth Allocated Proportional to
Expected Queue Length with Threshold Value and Bandwidth Allocated with
Threshold Interrupt. Bandwidth Allocated with Threshold Interrupt is proven to be
the most effective strategy as it could response to congestion immediately
ATM switch performance modeling with dynamic bandwidth allocation
One new technology that can be used to integrate various types of networking services today is ATM (Asynchronous Transfer Mode) where these services demand different QoS (Quality of Service). Allocating and scheduling the bandwidth for efficient utilisation of this valuable network resource is a critical issue. Dynamic Bandwidth Allocation is a promising scheme for this efficient utilisation. This study models an ATM switch using VBR traffic sources and tests its performance for three dynamic bandwidth allocation strategies. The traffic sources are modeled using the ON-OFF traffic source model
ATM switch performance with dynamic bandwidth allocation
A model is proposed for ATM switch to study its performance with dynamic bandwidth allocation. The proposed scheme allocates bandwidth dynamically, proportional to expected queue length and the threshold value associated with it. The scheme is then compared with the results of Lu and Hansson's research, where static bandwidth allocation and bandwidth allocated proportional to expected queue length are analyzed. The proposed scheme performs better under certain operating conditions when the threshold value is optimum