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Link Protection
Link protection is designed to safeguard networks from failure. Failures in high-speed networks have always been a concern of utmost importance. A single fiber cut can lead to heavy losses of traffic and protection-switching techniques have been used as the key source to ensure survivability in networks. Survivability can be addressed in many layers in a network and protection can be performed at the physical layer (SONET/SDH, Optical Transport Network), Layer 2 ( Ethernet, MPLS) and Layer 3 ( IP). Protection architectures like Path protection and Link protection safeguard the above-mentioned networks from different kinds of failures. In path protection, a backup path is used from the source to its destination to bypass the failure. In Link protection, the end nodes of the failed link initiate the protection. These nodes detect the fault responsible to initiate the protection mechanisms in order to detour the affected traffic from the failed link onto predetermined reserved path ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparency and translucency, transparent fiber made by Drawing (manufacturing), drawing glass (silica) or plastic to a diameter slightly thicker than that of a Hair's breadth, human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher Bandwidth (computing), bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less Attenuation, loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for Illumination (lighting), illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Special ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Two-fiber BLSR
A, or a, is the first letter and the first vowel of the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''a'' (pronounced ), plural ''aes''. It is similar in shape to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type. In English grammar, " a", and its variant " an", are indefinite articles. History The earliest certain ancestor of "A" is aleph (also written 'aleph), the first letter of the Phoenician alphabet, which consisted entirely of consonants (for that reason, it is also called an abjad to distinguish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiwavelength Optical Networking
Multiwavelength optical networking (MONET), is a method for communicating digital information using lasers over optical fiber. The method provides the next level of communication networks after Synchronous optical networking, SONET optical networks. MONET optical networks provide an even greater Bandwidth (computing), bandwidth capacity. This new method employs wave division multiplexing (WDM) technology for transporting large amounts of telephone and data traffic and allow for interoperability between equipment from different vendors. First developed by the secretive National Security Agency as author James Bamford points out in his book, "Body of Secrets: Anatomy of the Ultra-Secret National Security Agency". It was also discussed at the 1996 Military Communications Conference. ReferencesMultiwavelength Optical Networking Consortium(broken)''Multiwavelength Optical Networks - A layered Approach''by Thomas E. Stern and Krishna Bala''Body of Secrets: Anatomy of the Ultra-Secret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing And Wavelength Assignment
The routing and wavelength assignment (RWA) problem is an optical networking problem with the goal of maximizing the number of optical connections. Definition The general objective of the RWA problem is to maximize the number of established connections. Each connection request must be given a route and wavelength. The wavelength must be consistent for the entire path, unless the usage of wavelength converters is assumed. Two connections requests can share the same optical link, provided a different wavelength is used. The RWA problem can be formally defined in an integer linear program (ILP). The ILP formulation given here is taken from. Maximize: :C_0(\rho,q) = \sum_^ m_i subject to :m_i \geq 0, integer, i = 1, 2, ..., N_ :c_ \in , i = 1, 2, ..., P, j = 1, 2, ..., W :C^TB \leq l_ :m \leq 1_WC^TA :m_i \leq q_i\rho, i = 1, 2, ..., N_ N_ is the number of source-destination pairs, while m_i is the number of connections established for each source-destination pair. L is the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPLS Local Protection
MPLS Fast Reroute (also called MPLS local restoration or MPLS local protection) is a local restoration network resiliency mechanism. It is actually a feature of resource reservation protocol (RSVP) traffic engineering (RSVP-TE). In MPLS local protection each label switched path (LSP) passing through a facility is protected by a backup path which originates at the node immediately upstream to that facility. This node which redirects the traffic onto the preset backup path is called the Point of Local Repair (PLR), and the node where a backup LSP merges with the primary LSP is called Merge Point (MP). This mechanism (local protection) provides faster recovery because the decision of recovery is strictly local. For comparison, when recovery mechanisms are employed at the IP layer, restoration may take several seconds which is unacceptable for real-time applications (such as VoIP). In contrast, MPLS local protection meets the requirements of real-time applications with recovery times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPLS Fast-reroute Technique
Multiprotocol Label Switching (MPLS) is a routing technique in telecommunications networks that directs data from one node to the next based on labels rather than network addresses. Whereas network addresses identify endpoints the labels identify established paths between endpoints. MPLS can encapsulate packets of various network protocols, hence the ''multiprotocol'' component of the name. MPLS supports a range of access technologies, including T1/ E1, ATM, Frame Relay, and DSL. Role and functioning In an MPLS network, labels are assigned to data packets. Packet-forwarding decisions are made solely on the contents of this label, without the need to examine the packet itself. This allows one to create end-to-end circuits across any type of transport medium, using any protocol. The primary benefit is to eliminate dependence on a particular OSI model data link layer (layer 2) technology, and eliminate the need for multiple layer-2 networks to satisfy different types of traffic. Mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Routing
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone network (PSTN), and computer networks, such as the Internet. In packet switching networks, routing is the higher-level decision making that directs network packets from their source toward their destination through intermediate network nodes by specific packet forwarding mechanisms. Packet forwarding is the transit of network packets from one network interface to another. Intermediate nodes are typically network hardware devices such as routers, gateways, firewalls, or switches. General-purpose computers also forward packets and perform routing, although they have no specially optimized hardware for the task. The routing process usually directs forwarding on the basis of routing tables. Routing tables maintain a record of the routes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IS-IS
Intermediate System to Intermediate System (IS-IS, also written ISIS) is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this by determining the best route for data through a packet switching network. The IS-IS protocol is defined in ISO/IEC 10589:2002 as an international standard within the Open Systems Interconnection (OSI) reference design. The Internet Engineering Task Force (IETF) republished IS-IS in , but that RFC was later marked as ''historic'' by because it republished a draft rather than a final version of the (International Organization for Standardization) ISO standard, causing confusion. IS-IS has been called "the ''de facto'' standard for large service provider network backbones." Description IS-IS is an interior gateway protocol, designed for use within an administrative domain or network. This is in contrast to exterior gateway protocols, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OSPF
Open Shortest Path First (OSPF) is a routing protocol for Internet Protocol (IP) networks. It uses a link state routing (LSR) algorithm and falls into the group of interior gateway protocols (IGPs), operating within a single autonomous system (AS). OSPF gathers link state information from available routers and constructs a topology map of the network. The topology is presented as a routing table to the Internet Layer for routing packets by their destination IP address. OSPF supports Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6) networks and supports the Classless Inter-Domain Routing (CIDR) addressing model. OSPF is widely used in large enterprise networks. IS-IS, another LSR-based protocol, is more common in large service provider networks. Originally designed in the 1980s, OSPF is defined for IPv4 in protocol version 2 by RFC 2328 (1998)., Updated by RFC 5709, RFC 6549, RFC 6845, RFC 6860, RFC 7474, RFC 8042. The updates for IPv6 are spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NIC Teaming
NIC may refer to: Banking and insurance companies * National Insurance Corporation, Uganda * NIC Bank, a commercial bank in Kenya Politics, government and economics * National Ice Center, an agency that provides worldwide navigational ice analyses for the United States military and government * National Incubation Center, Ignite - National Technology Fund, Ministry of IT & Telecom, Government of Pakistan * Natal Indian Congress, a political party in South Africa formed by Mohandas Karamchand Gandhi * National Implementation Committee on FATA Reforms, a committee chaired by the Prime Minister of Pakistan regarding the Federally Administered Tribal Areas * National Indigenous Council, an advisory body to the Australian Government from late 2004 to early 2008 * National Informatics Centre, Government of India * National Infrastructure Commission, a UK government body advising on large-scale infrastructure projects * National Institute of Corrections, a division of the United S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
