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Service Assurance Agent
IP SLA (Internet Protocol Service Level Agreement) is an active computer network measurement technology that was initially developed by Cisco Systems. IP SLA was previously known as Service Assurance Agent (SAA) or Response Time Reporter (RTR). IP SLA is used to track network performance like latency, ping response, and jitter, it also helps us to provide service quality. Functions Routers and switches enabled with IP SLA perform periodic network tests or measurements such as * Hypertext Transfer Protocol (HTTP) GET * File Transfer Protocol (FTP) downloads * Domain Name System (DNS) lookups * User Datagram Protocol (UDP) echo, for VoIP jitter and mean opinion score (MOS) * Data-Link Switching (DLSw) (Systems Network Architecture (SNA) tunneling protocol) * Dynamic Host Configuration Protocol (DHCP) lease requests * Transmission Control Protocol (TCP) connect * Internet Control Message Protocol (ICMP) echo (remote ping) The exact number and types of available measurements depends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies. The nodes of a computer network can include personal computers, servers, networking hardware, or other specialised or general-purpose hosts. They are identified by network addresses, and may have hostnames. Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the transmission medium used to carry signals, bandwidth, communications pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunneling Protocol
In computer networks, a tunneling protocol is a communication protocol which allows for the movement of data from one network to another. It involves allowing private network communications to be sent across a public network (such as the Internet) through a process called encapsulation. Because tunneling involves repackaging the traffic data into a different form, perhaps with encryption as standard, it can hide the nature of the traffic that is run through a tunnel. The tunneling protocol works by using the data portion of a packet (the payload) to carry the packets that actually provide the service. Tunneling uses a layered protocol model such as those of the OSI or TCP/IP protocol suite, but usually violates the layering when using the payload to carry a service not normally provided by the network. Typically, the delivery protocol operates at an equal or higher level in the layered model than the payload protocol. Uses A tunneling protocol may, for example, allow a foreig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command-line Interface
A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and providing information to them as to what actions they are to perform. In some cases the invocation is conditional based on conditions established by the user or previous executables. Such access was first provided by computer terminals starting in the mid-1960s. This provided an interactive environment not available with punched cards or other input methods. Today, many users rely upon graphical user interfaces and menu-driven interactions. However, some programming and maintenance tasks may not have a graphical user interface and use a command line. Alternatives to the command-line interface include text-based user interface menus (for example, IBM AIX SMIT), keyboard shortcuts, and various desktop metaphors centered on the pointer (usual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterasys Networks
Enterasys Networks, Inc. was an American networking company. Enterasys products included networking equipment ranging from routers, switches, and IEEE 802.11 wireless access points and controllers. The company formed in March 2000 as a spin-off of Cabletron Systems. In addition to networking hardware such as switches, routers and wireless products, the company sold software for managing and securing networks such as intrusion prevention systems, network access control and security information management. The company's headquarters were in Salem, New Hampshire. History Enterasys had their initial public offering on August 6, 2001, with its shares trading on the New York Stock Exchange under symbol ETS. It claimed a $12.9 million profit in its first quarter after it was spun out of Cabletron in June 2001. A restatement in 2002 for recognizing revenue in improper time periods resulted in several quarters of losses. An investigation by the US Securities and Exchange Commissi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Juniper Networks
Juniper Networks, Inc. is an American multinational corporation headquartered in Sunnyvale, California. The company develops and markets networking products, including routers, switches, network management software, network security products, and software-defined networking technology. The company was founded in 1996 by Pradeep Sindhu, with Scott Kriens as the first CEO, who remained until September 2008. Kriens has been credited with much of Juniper's early market success. It received several rounds of funding from venture capitalists and telecommunications companies before going public in 1999. Juniper grew to $673 million in annual revenues by 2000. By 2001 it had a 37% share of the core routers market, challenging Cisco's once-dominant market-share. It grew to $4 billion in revenues by 2004 and $4.63 billion in 2014. Juniper appointed Kevin Johnson as CEO in 2008, Shaygan Kheradpir in 2013 and Rami Rahim in 2014. Juniper Networks originally focused on core routers, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetFlow
NetFlow is a feature that was introduced on Cisco routers around 1996 that provides the ability to collect IP network traffic as it enters or exits an interface. By analyzing the data provided by NetFlow, a network administrator can determine things such as the source and destination of traffic, class of service, and the causes of congestion. A typical flow monitoring setup (using NetFlow) consists of three main components: * Flow exporter: aggregates packets into flows and exports flow records towards one or more flow collectors. * Flow collector: responsible for reception, storage and pre-processing of flow data received from a flow exporter. * Analysis application: analyzes received flow data in the context of intrusion detection or traffic profiling, for example. Protocol description Routers and switches that support NetFlow can collect IP traffic statistics on all interfaces where NetFlow is enabled, and later export those statistics as NetFlow records toward at least on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Network Management Protocol
Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behaviour. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more. SNMP is widely used in network management for network monitoring. SNMP exposes management data in the form of variables on the managed systems organized in a management information base (MIB) which describe the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications. Three significant versions of SNMP have been developed and deployed. SNMPv1 is the original version of the protocol. More recent versions, SNMPv2c and SNMPv3, feature improvements in performance, flexibility and security. SNMP is a component of the Internet Protocol Suite as defined by the I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Service Provider
A service provider (SP) is an organization that provides services, such as consulting, legal, real estate, communications, storage, and processing services, to other organizations. Although a service provider can be a sub-unit of the organization that it serves, it is usually a third-party or outsourcing, outsourced supplier. Examples include telecommunications service providers (TSPs), application service providers (ASPs), storage service providers (SSPs), and internet service providers (ISPs). A more traditional term is service bureau. IT professionals sometimes differentiate between service providers by categorizing them as type I, II, or III. The three service types are recognized by the IT industry although specifically defined by ITIL and the U.S. Telecommunications Act of 1996. *Type I: internal service provider *Type II: shared service provider *Type III: external service provider Type III SPs provide IT services to external customers and subsequently can be referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisco IOS
The Internetworking Operating System (IOS) is a family of proprietary network operating systems used on several router and network switch models manufactured by Cisco Systems. The system is a package of routing, switching, internetworking, and telecommunications functions integrated into a multitasking operating system. Although the IOS code base includes a cooperative multitasking kernel, most IOS features have been ported to other kernels, such as Linux and QNX, for use in Cisco products. Not all Cisco networking products run IOS. Exceptions include some Cisco Catalyst switches, which run IOS XE, and Cisco ASR routers, which run either IOS XE or IOS XR; both are Linux-based operating systems. For data center environments, Cisco Nexus switches (Ethernet) and Cisco MDS switches ( Fibre Channel) both run Cisco NX-OS, also a Linux-based operating system. History The IOS network operating system was created from code written by William Yeager at Stanford University, which w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ping (networking Utility)
ping is a computer network administration software utility used to test the reachability of a host on an Internet Protocol (IP) network. It is available for virtually all operating systems that have networking capability, including most embedded network administration software. Ping measures the round-trip time for messages sent from the originating host to a destination computer that are echoed back to the source. The name comes from active sonar terminology that sends a pulse of sound and listens for the echo to detect objects under water. Ping operates by means of Internet Control Message Protocol (ICMP) packets. ''Pinging'' involves sending an ICMP echo request to the target host and waiting for an ICMP echo reply. The program reports errors, packet loss, and a statistical summary of the results, typically including the minimum, maximum, the mean round-trip times, and standard deviation of the mean. The command-line options of the ping utility and its output vary between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Control Message Protocol
The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when communicating with another IP address, for example, an error is indicated when a requested service is not available or that a host or router could not be reached. ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems, nor is it regularly employed by end-user network applications (with the exception of some diagnostic tools like ping and traceroute). ICMP for IPv4 is defined in RFC 792. A separate ICMPv6, defined by RFC 4443, is used with IPv6. Technical details ICMP is part of the Internet protocol suite as defined in RFC 792. ICMP messages are typically used for diagnostic or control purposes or generated in response to errors in IP operations (as specified in RFC 1122 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmission Control Protocol
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP, which is part of the Transport Layer of the TCP/IP suite. SSL/TLS often runs on top of TCP. TCP is connection-oriented, and a connection between client and server is established before data can be sent. The server must be listening (passive open) for connection requests from clients before a connection is established. Three-way handshake (active open), retransmission, and error detection adds to reliability but lengthens latency. Applica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
