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Quality of Service in Switch/Routers
Published in James Aweya, Designing Switch/Routers, 2023
Differentiated services (DiffServ) is a more recent QoS architecture defined by the IETF [RFC2474] [RFC2475] [RFC3260]. DiffServ specifies a simple and scalable coarse-grained, class-based mechanism for traffic forwarding in IP networks. It defines a mechanism for classifying and marking packets as belonging to a specific CoS. It includes the concept of marking IP packets with priority values that allow routers to classify the marked packets into traffic classes, each associated with certain forwarding behaviors in the network. Using DiffServ-based classification, each packet is placed into a limited number of traffic classes (or queues), compared to the fine-grained, flow-based architecture (Integrated Services (IntServ) architecture [RFC1633]) where network traffic is differentiated based on the requirements of an individual flow. DiffServ allows each router on the network to differentiate traffic based on the limited range of packet markings and traffic classes. Each traffic class can be managed differently, allowing routers to provide preferential treatment for higher-priority traffic on the network.
SRv6 TE
Published in Zhenbin Li, Zhibo Hu, Cheng Li, SRv6 Network Programming, 2021
Zhenbin Li, Zhibo Hu, Cheng Li
In addition to binding SIDs and color values, traffic steering can also be performed based on the Differentiated Services Code Point (DSCP) values encapsulated in IP headers. This helps further classify services that match the same route but different origins. For example, an operator can configure multiple SRv6 Policies as a group on the headend, specify the mapping between each SRv6 Policy and DSCP value in the group, and bind services to the group. In this way, after receiving the service traffic, the headend searches for the corresponding SRv6 Policy in the group according to the DSCP value carried in the IP header, and then completes traffic steering accordingly. It is important to note that, in this traffic steering mode, services must be differentiated at the origin and have different DSCP values specified.
Performance Study on Switch and Network
Published in Naoaki Yamanaka, High-Performance Backbone Network Technology, 2020
As a scalable IP-QoS architecture, Differentiated Services (Diffserv) is considered to be useful within the service provider’s backbone and enterprise networks. T. Ishihara et al. propose a Diffserv over ATM architecture to provide Diffserv-based QoS over ATM access networks in Paper 5.10. They present a developed prototype ATM card to support Diffserv-based QoS.
Machine repair system with threshold recovery policy, unreliable servers and phase repairs
Published in Quality Technology & Quantitative Management, 2023
Kamlesh Kumar, Madhu Jain, Chandra Shekhar
The queueing modeling of machine repair systems with phase services has a profound impact on industrial congestion scenarios. The notion of phase service in machine repair issues is included in order to provide a higher quality of service to failing machines. In manufacturing systems, raw materials are transformed into completed products through a sequence of processing steps. The Internet and Voice-over-IP (VoIP) technologies enable users to make calls over IP networks, and this service process (VoIP) is accomplished in three phases: connection establishment, information transfer and accessing differentiated services. The phase service queue can also be observed in computer and communication networks, where messages are processed from a message generation center in multiple phases. Chakravarthy and Agarwal (2003) studied a repairable system with an unreliable server and phase repair to evaluate the optimal number of machines allocated to the server in order to maximize profit per unit time. Jain and Bhagat (2016) suggested a model for a retrial queueing system with phase repair and reneging. Choudhury et al. (2015) examined the performance of a retrial queue model with two types of phase service.
Software-Defined Networking Techniques to Improve Mobile Network Connectivity: Technical Review
Published in IETE Technical Review, 2018
Apart from the earlier two approaches, which classify packet-in message and application type, OpenQoS [23] sorts incoming traffic as multimedia and data. Multimedia traffic on QoS guaranteed routes can be allocated dynamically while traditional shortest path can be used by data traffic over OpenFlow networks. OpenQoS is different from the current QoS architecture that enables QoS based on dynamic QoS routing rather than using resource reservation in Integrated Services (IntServ) architecture or priority queuing in Differentiated Services (DiffServ) architecture. Also, available bandwidth for each link is monitored by OpenQoS controller periodically in order to detect whether congestion has happened while link cost parameters are determined for problem optimization. If congestion takes place, QoS routes can be rerouted by deleting route in the routing table which matches multimedia QoS packet in the flow table of the switches so that new flow entries are defined for the multimedia QoS packet [28]. OpenQoS first checks if the packet belongs to multimedia packet based on predefined flow setups. Two paths will be calculated based on QoS optimized path and shortest path. Upon receiving packet-in messages at OpenQoS controller, typical QoS indicator, such as packet loss rate, bandwidth, and delay for each link are used to calculate QoS route and new flow definitions are pushed to forwarders along the path.
Differentiated service policy in smart warehouse automation
Published in International Journal of Production Research, 2018
Zijian He, Vaneet Aggarwal, Shimon Y. Nof
The probabilistic queuing policy and the differentiated objective function in this research are motivated by the policies in networking and cloud storage research, which focuses on digital storage. For instance, a start-time fair queuing algorithm for packet switching network (Goyal, Vin, and Chen 1997), an efficient fair queuing algorithm for packet switching network (Stiliadis and Varma 1998), three-level approaches for differentiated services in measuring Web quality of service (Lee and Park 2009), joint optimisation of encoded chunks placement while optimising scheduling policy of erasure-coded storage system with arbitrary service time distribution, and consisting of multiple heterogeneous files (Xiang et al. 2014, 2016). Probabilistic scheduling is used by the latter, and the placement and access of contents are optimised for minimising access latency in distributed storage systems. This particular idea is extended in this article for physical warehouse systems, where we use a probabilistic strategy for order pickup. Differentiated services have been considered in many areas, including wireless networks (Chen and Mohapatra 1999; Veres et al. 2001; Le, Hossain, and Alfa 2006), cloud computing (Grit and Chase 2008; Li 2009; Rao et al. 2013), distributed scheduling (Jin, Chase, and Kaur 2004; Shue, Freedman, and Shaikh 2012; Aggarwal et al. 2017; Xiang, Lan, et al. 2017), machine scheduling (Lenstra, Kan, and Brucker 1977; Weng, Lu, and Ren 2001; Murray, Chao, and Khuller 2016), supply chain (Morash and Clinton 1998; Hilletofth 2009), smart grids (Deshpande, Kim, and Thottan 2011; Bitar and Low 2012; Negrete-Pincetic and Meyn 2012). The differentiated services have been studied even dating back to 1950s (Smith 1956).