967 research outputs found
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Survey of switching techniques in high-speed networks and their performance
One of the most promising approaches for high speed networks for integrated service applications is fast packet switching, or ATM (Asynchronous Transfer Mode). ATM can be characterized by very high speed transmission links and simple, hard wired protocols within a network. To match the transmission speed of the network links, and to minimize the overhead due to the processing of network protocols, the switching of cells is done in hardware switching fabrics in ATM networks.A number of designs has been proposed for implementing ATM switches. While many differences exist among the proposals, the vast majority of them is based on self-routing multi-stage interconnection networks. This is because of the desirable features of multi-stage interconnection networks such as self-routing capability and suitability for VLSI implementation.Existing ATM switch architectures can be classified into two major classes: blocking switches, where blockings of cells may occur within a switch when more than one cell contends for the same internal link, and non-blocking switches, where no internal blocking occurs. A large number of techniques has also been proposed to improve the performance of blocking and nonblocking switches. In this paper, we present an extensive survey of the existing proposals for ATM switch architectures, focusing on their performance issues
On-board B-ISDN fast packet switching architectures. Phase 2: Development. Proof-of-concept architecture definition report
For the next-generation packet switched communications satellite system with onboard processing and spot-beam operation, a reliable onboard fast packet switch is essential to route packets from different uplink beams to different downlink beams. The rapid emergence of point-to-point services such as video distribution, and the large demand for video conference, distributed data processing, and network management makes the multicast function essential to a fast packet switch (FPS). The satellite's inherent broadcast features gives the satellite network an advantage over the terrestrial network in providing multicast services. This report evaluates alternate multicast FPS architectures for onboard baseband switching applications and selects a candidate for subsequent breadboard development. Architecture evaluation and selection will be based on the study performed in phase 1, 'Onboard B-ISDN Fast Packet Switching Architectures', and other switch architectures which have become commercially available as large scale integration (LSI) devices
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Survey of traffic control schemes and error control schemes for ATM networks
Among the techniques proposed for B-ISDN transfer mode, ATM concept is considered to be the most promising transfer technique because of its flexibility and efficiency. This paper surveys and reviews a number of topics related to ATM networks. Those topics cover congestion control, provision of multiple classes of traffic, and error control. Due to the nature of ATM networks, those issues are far more challenging than in conventional networks. Sorne of the more promising solutions to those issues are surveyed, and the corresponding results on performance are summarized. Future research problems in ATM protocol aspect are also presented
Product-form solutions for integrated services packet networks and cloud computing systems
We iteratively derive the product-form solutions of stationary distributions
of priority multiclass queueing networks with multi-sever stations. The
networks are Markovian with exponential interarrival and service time
distributions. These solutions can be used to conduct performance analysis or
as comparison criteria for approximation and simulation studies of large scale
networks with multi-processor shared-memory switches and cloud computing
systems with parallel-server stations. Numerical comparisons with existing
Brownian approximating model are provided to indicate the effectiveness of our
algorithm.Comment: 26 pages, 3 figures, short conference version is reported at MICAI
200
On the Stability of Isolated and Interconnected Input-Queued Switches under Multiclass Traffic
In this correspondence, we discuss the stability of scheduling algorithms for input-queueing (IQ) and combined input/output queueing (CIOQ) packet switches. First, we show that a wide class of IQ schedulers operating on multiple traffic classes can achieve 100 % throughput. Then, we address the problem of the maximum throughput achievable in a network of interconnected IQ switches and CIOQ switches loaded by multiclass traffic, and we devise some simple scheduling policies that guarantee 100 % throughput. Both the Lyapunov function methodology and the fluid modeling approach are used to obtain our results
Priority Control in ATM Network for Multimedia Services
The communication network of the near future is going to be based on Asynchronous
Transfer Mode (ATM) which has widely been accepted by equipment vendors and
service providers. Statistical multiplexing technique, high transmission speed and
multimedia services render traditional approaches to network protocol and control
ineffective. The ATM technology is tailored to support data, voice and video traffic
using a common 53 byte fixed length cell based format with connection oriented
routing.
Traffic sources in A TM network such as coded video and bulk data
transfer are bursty. These sources generate cells at a near-peak rate during their active
period and generate few cells during relatively long inactive period. Severe network
congestion might occur as a consequence of this dynamic nature of bursty traffic.
Even though Call Admission Control (CAC) is appropriately carried out for deciding
acceptance of a new call, Quality of Service (QOS) may be beyond the requirement
limits as bursty traffic are piled up. So, priority control, in which traffic stream are
classified into several classes according to their QOS requirements and transferred
according to their priorities, becomes an important research issue in ATM network. There are basically two kinds of priority management schemes: time
priority scheme that gives higher priority to services requiring short delay time and
the space priority scheme that gives high priority cells requiring small cell loss ratio.
The possible drawbacks of these time and space priority schemes are the processing
overhead required for monitoring cells for priority change, especially in the case of
time priority schemes. Also, each arriving cell needs to be time stamped. The
drawback of the space priority scheme lies in the fact that buffer management
complexity increases when the buffer size becomes large because cell sequence
preservation requires a more complicated buffer management logic.
In this thesis, a Mixed Priority Queueing or MPQ scheme is proposed
which includes three distinct strategies for priority control method -- buffer
partitioning, allocation of cells into the buffer and service discipline. The MPQ
scheme is, by nature, a non-fixed priority method in which delay times and loss
probabilities of each service class are taken into account and both delay times and
loss probabilities can be controlled with less dependency compared with the fixed
priority method, where priority grant rule is fixed according to the service class, and
the priority is always given to the highest class cell among cells existing in the
buffer. The proposed priority control is executed independently at each switching
node as a local buffer management. Buffer partitioning is applied to overcome the
weakness of the single buffer
Scheduling algorithms for high-speed switches
The virtual output queued (VOQ) switching architecture was adopted for high speed switch implementation owing to its scalability and high throughput. An ideal VOQ algorithm should provide Quality of Service (QoS) with low complexity. However, none of the existing algorithms can meet these requirements.
Several algorithms for VOQ switches are introduced in this dissertation in order to improve upon existing algorithms in terms of implementation or QoS features. Initially, the earliest due date first matching (EDDFM) algorithm, which is stable for both uniform and non-uniform traffic patterns, is proposed. EDDFM has lower probability of cell overdue than other existing maximum weight matching algorithms. Then, the shadow departure time algorithm (SDTA) and iterative SDTA (ISDTA) are introduced. The QoS features of SDTA and ISDTA are better than other existing algorithms with the same computational complexity. Simulations show that the performance of a VOQ switch using ISDTA with a speedup of 1.5 is similar to that of an output queued (OQ) switch in terms of cell delay and throughput. Later, the enhanced Birkhoff-von Neumann decomposition (EBVND) algorithm based on the Birkhoff-von Neumann decomposition (BVND) algorithm, which can provide rate and cell delay guarantees, is introduced. Theoretical analysis shows that the performance of EBVND is better than BVND in terms of throughput and cell delay. Finally, the maximum credit first (MCF), the Enhanced MCF (EMCF), and the iterative MCF (IMCF) algorithms are presented. These new algorithms have the similar performance as BNVD, yet are easier to implement in practice
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