T-3 TCP in Visual Basic .NET

Encoding ECC200 in Visual Basic .NET T-3 TCP

Telecommunications Network Protocol (Telnet) An application layer Transmission Control Protocol/Internet Protocol (TCP/IP) client/server protocol used to remotely control a computer at another location. A mainstay of UNIX networking, Telnet is a true remote control application. When you access another computer and run a program, it is the processor in the remote computer that executes that program. The Telnet service is command-line-based, making it relatively useless on computers running Microsoft Windows operating systems, which rely on a graphical interface. However, all versions of the Windows operating system include a Telnet client. Windows Server 2003 also includes a Telnet server, but compared to a UNIX Telnet implementation, it has relatively few functions. This is because the primary user interface in a UNIX operating system is character-based, while the Windows interface is primarily graphical. Telnet See Telecommunications Network Protocol (Telnet).

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Time to Live (TTL) A timer value included in packets sent over networks based on Transmission Control Protocol/Internet Protocol (TCP/IP) that tells routers when a packet has been forwarded too many times. For Domain Name System (DNS), TTL values are used in resource records within a zone to determine how long requesting clients should cache and use this information when it appears in a query response answered by a DNS server for the zone. TLS See Transport Layer Security (TLS). token passing A Media Access Control (MAC) mechanism used on ring topology networks that uses a separate frame type called a token, which circulates around the network from computer to computer. Only the computer in possession of the token is permitted to transmit its data, which prevents computers from transmitting at the same time, causing collisions. On receipt of the token, a computer transmits a packet and either regenerates a new token immediately or waits for the packet to circulate around the network and return to its source, at which time the computer removes the packet and transmits the token frame. Unlike the Carrier Sense Multiple Access with Collision Detection (CSMA/CD) MAC mechanism, no collisions occur on a properly functioning token passing network. Token passing is used by several different data-link layer protocols, including Token Ring and Fiber Distributed Data Interface (FDDI). Token Ring A data-link layer protocol originally developed by IBM that is used on local area networks (LANs) with a ring topology. Running at 4 Mbps or 16 Mbps, Token Ring networks use the token passing Media Access Control (MAC) mechanism. Although they use a logical ring topology, Token Ring networks are physically cabled like a star, using a hub called a multistation access unit (MAU) that transmits incoming packets through each successive port in turn. Early Token Ring networks used a shielded twisted-pair (STP) cable known as IBM Type 1, but today most Token Ring networks use unshielded twisted-pair (UTP) cable. top-level domain The highest level in the Domain Name System (DNS) namespace and the rightmost word in a DNS name. For example, in the DNS name www.microsoft.com, com is the top-level domain. Domain names that are rooted hierarchically at the first tier of the domain namespace directly beneath the root (.) of the Domain Name System (DNS) namespace. On the Internet, top-level domain names such as .com and .org are used to classify and assign second-level domain names (such as microsoft.com) to individual organizations and businesses according to their organizational purpose. topology The method used to install network cabling and connect the network computers to the cable, which is determined by the data-link layer protocol and cable type you choose. The three basic network topologies are the bus, in which one computer is connected to the next in daisy-chain fashion; the star, in which all the computers are connected to a central hub; and the ring, in which the computers