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Sipura Technology
Sipura Technology, Inc. was a Voice over IP (VoIP) startup company based in San Jose, California founded in 2003 with its siblings VideoCore and Komodo Technology, Inc. Sipura made VoIP telephone adapters including the Sipura Phone Adapter SPA2100, SPA3000, SPA9000, as well as SPA series IP phones, like the SPA941. Cisco Systems acquired VOIP maker Sipura Technologies for its Linksys division on April 26, 2005. Ever since, Sipura has been releasing its SPA series equipment under the Linksys brand. Products *SPA2000: Basic analog telephone adapter (ATA) that allows two plain old telephone service (POTS) phones or fax machines to be connected to an Ethernet network in order to make and receive telephone calls or faxes. *SPA2100: Similar to the SPA2000 with the addition of an Ethernet router. Functions of the built-in router include QoS. *SPA3000: The SPA3000 has one analog telephone adapter port ( FXS) and one FXO port for connection to the public switched telephone netw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Over IP
Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of speech, voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet telephony, broadband telephony, and broadband phone service specifically refer to the provisioning of communications services (voice, fax, Short Message Service, SMS, voice-messaging) over the Internet, rather than via the public switched telephone network (PSTN), also known as plain old telephone service (POTS). Overview The steps and principles involved in originating VoIP telephone calls are similar to traditional digital telephony and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a circuit-switched network, the digital information is packetized and transmission occurs as IP packets over a packet-switched network. They transport media streams using spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Public Switched Telephone Network
The public switched telephone network (PSTN) provides Communications infrastructure, infrastructure and services for public Telecommunications, telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local telephony operators. These consist of telephone lines, fiber optic cables, microwave transmission links, Routing in cellular networks, cellular networks, communications satellites, and undersea telephone cables, all interconnected by switching centers which allow most telephones to communicate with each other. Originally a network of fixed-line Analog signal processing, analog telephone systems, the PSTN is now almost entirely digital in its core network and includes mobile and other networks, as well as fixed telephones. The technical operation of the PSTN adheres to the standards created by the ITU-T. These standards allow different networks in different countries to interconnect seamlessly. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisco Systems Acquisitions
Cisco is an American computer networking company. Cisco made its first acquisition in 1993, which was followed by a series of further acquisitions. History Founded in 1984, Cisco did not acquire a company during the first seven years of its existence; but, on September 24, 1993, Cisco acquired Crescendo Communications, a LAN switching company. Following the first Cisco takeover purchase, acquisitions have constituted 50 percent of the company's business activity. The company's largest acquisition is the purchase of Scientific-Atlanta—a manufacturer of cable television, telecommunications and broadband equipment—for US$6.9 billion. The purchase represented the interest that Cisco had in Internet television, as spending on switches and routers decreased, and expanded the corporation's consumer product base after its prior acquisition of Linksys Inc., a producer of wireless networking products for homes and small businesses. Cisco chief executive officer (CEO) at the time, Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obihai Technology
Obihai Technology is a company that manufactures analog telephone adapters that support Session Initiation Protocol (SIP), XMPP, and Google Voice compatible Internet telephony. History The company, based in California's Silicon Valley, was founded in 2010 by Jan Fandrianto and Sam Sin, the same people who introduced the first analog telephone adaptors as Komodo Technology in the 1990s and formed Sipura Technology in 2002. Both prior companies were acquired by Cisco Systems, in 2000 and 2005 respectively, and integrated into that company's Linksys division. Linksys was sold to Belkin in 2013. In January 2018, Polycom acquired Obihai. Polycom "expects to add more cloud-based capabilities and Analog Terminal Adapter solutions to its solutions portfolio". The deal is expected to close early in the first quarter of 2018. In 2022, Poly was sold onwards to HP. Products Obihai is notable primarily for manufacturing analog telephone adapters that connect standard push-button telephon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Over Ethernet
Power over Ethernet, or PoE, describes any of several standards or ad hoc systems that pass electric power along with data on twisted-pair Ethernet cabling. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points (WAPs), Internet Protocol (IP) cameras, and voice over Internet Protocol (VoIP) phones. There are several common techniques for transmitting power over Ethernet cabling. Three of them have been standardized by Institute of Electrical and Electronics Engineers (IEEE) standard IEEE 802.3 since 2003. These standards are known as ''alternative A'', ''alternative B'', and ''4PPoE''. For 10BASE-T and 100BASE-TX, only two of the four signal pairs in typical Cat 5 cable are used. Alternative B separates the data and the power conductors, making troubleshooting easier. It also makes full use of all four twisted pairs in a typical Cat 5 cable. The positive voltage is applied to pins 4 and 5, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid-crystal Display
A liquid-crystal display (LCD) is a flat-panel display A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment. Flat-panel displays are thin, lightweight, provide better l ... or other Electro-optic modulator, electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but instead use a backlight or reflector (photography), reflector to produce images in color or monochrome monitor, monochrome. LCDs are available to display arbitrary images (as in a general-purpose computer display) or fixed images with low information content, which can be displayed or hidden. For instance: preset words, digits, and seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, exc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual-tone Multi-frequency Signaling
Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. DTMF was first developed in the Bell System in the United States, and became known under the trademark Touch-Tone for use in push-button telephones supplied to telephone customers, starting in 1963. DTMF is standardized as ITU-T Recommendation Q.23. It is also known in the UK as ''MF4''. The Touch-Tone system using a telephone keypad gradually replaced the use of rotary dial and has become the industry standard for landline and mobile service. Other multi-frequency systems are used for internal signaling within the telephone network. Multifrequency signaling Before the development of DTMF, telephone numbers were dialed by users with a loop-disconnect (LD) signaling, more commonly known as pulse dialing (dial pulse, DP) in the United States. It functions by int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quality Of Service
Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitatively measure quality of service, several related aspects of the network service are often considered, such as packet loss, bit rate, throughput, transmission delay, availability, jitter, etc. In the field of computer networking and other packet-switched telecommunication networks, quality of service refers to traffic prioritization and resource reservation control mechanisms rather than the achieved service quality. Quality of service is the ability to provide different priorities to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. Quality of service is particularly important for the transport of traffic with special requirements. In particular, developers have introduced Voice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port Forwarding
In computer networking, port forwarding or port mapping is an application of network address translation (NAT) that redirects a communication request from one address and port number combination to another while the packets are traversing a network gateway, such as a router or firewall. This technique is most commonly used to make services on a host residing on a protected or masqueraded (internal) network available to hosts on the opposite side of the gateway (external network), by remapping the destination IP address and port number of the communication to an internal host. Purpose Port forwarding allows remote computers (for example, computers on the Internet) to connect to a specific computer or service within a private local-area network (LAN). In a typical residential network, nodes obtain Internet access through a DSL or cable modem connected to a router or network address translator (NAT/NAPT). Hosts on the private network are connected to an Ethernet switch or commu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Old Telephone Service
Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from 1876 until 1988 in the United States when the Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) was introduced, followed by cellular telephone systems, and voice over IP (VoIP). POTS remains the basic form of residential and small business service connection to the telephone network in many parts of the world. The term reflects the technology that has been available since the introduction of the public telephone system in the late 19th century, in a form mostly unchanged despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN). Characteristics POTS is characterized by several aspects: *Bi-directional (full duplex) comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Private Branch Exchange
A business telephone system is a multiline telephone system typically used in business environments, encompassing systems ranging in technology from the key telephone system (KTS) to the private branch exchange (PBX). A business telephone system differs from an installation of several telephones with multiple central office (CO) lines in that the CO lines used are directly controllable in key telephone systems from multiple telephone stations, and that such a system often provides additional features related to call handling. Business telephone systems are often broadly classified into key telephone systems, and private branch exchanges, but many hybrid systems exist. A key telephone system was originally distinguished from a private branch exchange in that it did not require an operator or attendant at the switchboard to establish connections between the central office trunks and stations, or between stations. Technologically, private branch exchanges share lineage with centra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Service Provider
An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privately owned. Internet services typically provided by ISPs can include Internet access, Internet transit, domain name registration, web hosting, Usenet service, and colocation. An ISP typically serves as the access point or the gateway that provides a user access to everything available on the Internet. Such a network can also be called as an eyeball network. History The Internet (originally ARPAnet) was developed as a network between government research laboratories and participating departments of universities. Other companies and organizations joined by direct connection to the backbone, or by arrangements through other connected companies, sometimes using dialup tools such as UUCP. By the late 1980s, a process was set in place towa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
