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Photonic Switch
Published in Naoaki Yamanaka, High-Performance Backbone Network Technology, 2020
This chapter describes a new optical label (OL) switching technique; wavelength and pilot tone frequency (PTF) are combined to form labels that are used to control transport network routing. This technique is very attractive for achieving simple nodes that offer extremely rapid forwarding. The processing speed of Internet protocol network nodes has been increased by the use of hardware switches based on application specific integrated circuits, and link control methods such as multi-protocol label switching. For constructing an optical label switching core node that offers high-speed and small latency time, it is important to implement all-optical OL conversion. The author examines a conversion method that performs wavelength and PTF conversion in one go, by using the saturation effect based on cross-gain modulation in a semiconductor optical amplifier. Experiments confirmed the feasibility of the proposed optical label discrimination process and optical label conversion process.
Optical networks
Published in Matthew N. O. Sadiku, Optical and Wireless Communications, 2018
Label switching is key to MPLS. At the ingress point of an MPLS network, the label edge router (LER) adds a label to each incoming IP packet according to its destination and the state of the network. Label switching relies on the setup of switched paths through the network, which are called label switching paths (LSPs). In other words, LSP is an established logical MPLS connection that links a LER via a label switched router (LSR) to another LER, as shown in Figure 4.25. When a packet is sent on an LSP, a label is applied to the packet, as shown in Figure 4.26. On ATM links, for example, the label may be carried as the virtual circuit identifier and/or virtual path identifier applied to each ATM cell. A similar scheme has been proposed for SONET.
7 Ip Packet Transport
Published in Wes Simpson, Video Over IP, 2013
The basic concept of MPLS is label switching, which uses simple labels on packets, cells, or frames to send data along preestablished paths, known as Label Switched Paths (LSPs). MPLS is connection oriented, which means that a path from the sender to the receiver is established prior to data transmission, similar to ATM and TCP. LSPs run from one edge of the MPLS network to the other and can be configured via a variety of different software protocols that are used by routers. This task is not easy; a significant amount of effort has gone into creating the software that distributes the labels to all of the routers along a given LSP. Once the labels have been distributed to all the network elements, MPLS networks are very fast, because each router along the LSP needs to look only at the label, rather than processing the entire packet.
A Survey on Packet Switching Networks
Published in IETE Journal of Research, 2022
The traffic demand has been increased because of delay-sensitive applications and increasing bandwidth, and the circuit-based networks can no longer fulfil traffic demands. Hence, Multiprotocol Label Switching (MPLS) has been introduced to optimize the network resources and manage the traffic [19]. MPLS is a technique used to forward the packets based on labels. The lookup process in the switching table in the MPLS network is less time-consuming and complex than the routing lookup process in IP routing. MPLS network provides many advantages and features like Quality of Service (QoS) and traffic engineering [20]. In an MPLS network, the packets forwarded are based on labels, and these labels are injected by the ingress edge router and removed by the egress edge router. Therefore, the source and destination workstations do not know about the labels. This technique is also called label switching.
Virtualised Environment for Learning SDN-based Networking
Published in IETE Journal of Education, 2020
Oscar Polanco, Fabio G. Guerrero
Many other network concepts such as, for instance, routing (BGP, MP-BGP, OSPF, IS-IS, EIGRP, etc.), multiple protocol label switching (MPLS) networks, and services can also be practised. We have also found the virtualisation approach to be useful for network security analysis, MPLS traffic engineering, and IPv6 based networks. Using the virtualised educational network environment, students can work autonomously to implement a campus network with layer 2 technologies and protocols (e.g. VLANs, IEEE 802.1q, STP, multiple STP, link aggregation control protocol) as well as layer 3 technologies and protocols (e.g. virtual router redundancy protocol, OSPF, IPv4, and IPv6). Students can also implement scenarios for management and automation (SNMP, Ansible) of a basic ISP infrastructure and, if necessary, connect it to the physical world, along with configuring MPLS services that ISPs usually provide to users (e.g. VPN-MPLS, central services, access to the Internet, etc.). The virtualization approach has several practical advantages. Owing to its associated costs, it is difficult to keep the network equipment of a computer network laboratory always updated. Internet service providers, for obvious reasons, hardly allow outsiders to get details of their network topologies, protocols, and settings. Carrying out an instructional activity involving sensitive aspects such as routing in an operational network is not realistic.
An offline scheme for reducing cost of protection in all-optical WDM mesh networks with fast recovery
Published in International Journal of Parallel, Emergent and Distributed Systems, 2019
Vishal Dey, Abhishek Bandyopadhyay, Uma Bhattacharya, Monish Chatterjee
The work [5] proposes an approach of survivable routing for SSP in mesh WDM networks with nodes having partial wavelength conversion facility. The authors [6] study the problem of Routing and Wavelength Assignment (RWA) of lightpaths while employing SSP in all-optical networks. In [7], the researchers study SSP under the Generalized Multi-Protocol Label Switching based recovery framework and proposes a routing algorithm for SSP. SSP schemes can however be less efficient in terms of backup capacity sharing due to absence of wavelength conversion in all-optical networks. In [4] the authors propose an online protection scheme named streams that incorporate the combined benefits of both DPP and SPP to provide fast and capacity efficient protection from all single link and single node failures. The work [8] extends the streams approach [4] in order to make it more resource-efficient and proposes an offline protection scheme named generalized streams. Researchers [23] propose a protection scheme called mixed SPP for studying the problem of survivable routing to prevent single link failure where some primary and backup paths are allowed to share common mixed resources.