Network Protocols Indroduction

Network Protocols

TCP: TCP is a transport layer protocol used by applications that require guaranteed delivery. It provides handling for both timeouts and retransmissions.

IP: The Internet Protocol (IP) is the principal communications protocol used for relaying datagrams (also known as network packets) across an internetwork using the Internet Protocol Suite. Responsible for routing packets across network boundaries, it is the primary protocol that establishes the Internet.

IPX: Internetwork Packet Exchange (IPX) is the OSI-model Network layer protocol in the IPX/SPX protocol stack. The IPX/SPX protocol stack is supported by Novell's NetWare network operating system. Because of Netware's popularity through the late 1980s into the mid- 1990s, IPX became a popular internetworking protocol.

SPX: Sequenced Packet Exchange operates at the transport layer providing connection oriented communication on top of IPX.

Apple Talk: AppleTalk is a proprietary suite of networking protocols developed by Apple Inc. for their Mac computers. AppleTalk included a number of features that allowed local area networks to be connected with no prior setup or the need for a centralized router or server of any sort. Connecting together AppleTalk equipped systems would automatically assign addresses, update the distributed namespace, and configure any required inter-networking routing. It was a plug-n-play system.

SMB: In computer networking, Server Message Block (SMB), also known as Common Internet File System (CIFS) operates as an application-layer network protocol mainly used for providing shared access to files, printers, and other communications between nodes on a network.

DLC: There is also a network protocol with the name Data Link Control. It is comparable to better known protocols such as TCP/IP or AppleTalk. DLC is a transport protocol used by IBM SNA mainframe computers and peripherals and compatible equipment. In computer networking, it is typically used for communications between network-attached printers, computers and servers, for example by HP in their JetDirect print servers. While it was widely used up until the time of Windows 2000, the DLC protocol is no longer included in Windows XP.

NetBIOS Names: NetBIOS stands for Network Basic Input/output System. It provides services related to the session layer of the OSI model allowing applications on separate computers to communicate over a local area network. As strictly an API, NetBIOS is not a networking protocol. Older operating systems run NetBIOS over IEEE 802.2 and IPX/SPX using the NetBIOS Frames (NBF) and NetBIOS over IPX/SPX (NBX) protocols, respectively. In modern networks, NetBIOS normally runs over TCP/IP via the NetBIOS over TCP/IP (NBT) protocol. This results in each computer in the network having both an IP address and a NetBIOS name corresponding to a (possibly different) host name.

L2CAP: L2CAP is used within the Bluetooth protocol stack. It passes packets to either the Host Controller Interface (HCI) or on a host less system, directly to the Link Manager/ACL link. L2CAP's functions include:

·         Multiplexing data between different higher layer protocols.

·         Segmentation and reassembly of packets.

·         Providing one-way transmission management of multicast data to a group of other Bluetooth devices.

·         Quality of service (QoS) management for higher layer protocols.

RFCOMM: The Bluetooth protocol

RFCOMM is a simple set of transport protocols, made on top of the L2CAP protocol, providing emulated RS-232 serial ports (up to sixty simultaneous connections to a Bluetooth device at a time). The protocol is based on the ETSI standard TS 07.10. RFCOMM is sometimes called serial port emulation. The Bluetooth serial port profile is based on this protocol.

SDP: Service discovery protocols are network protocols which allow automatic detection of devices and services offered by these devices on a computer network. Service discovery requires a common language to allow software agents to make use of one another's services without the need for continuous user intervention.

CARP: The Common Address Redundancy Protocol or CARP is a protocol which allows multiple hosts on the same local network to share a set of IP addresses. Its primary purpose is to provide failover redundancy, especially when used with firewalls and routers. In some configurations CARP can also provide load balancing functionality. It is a free, non-patent encumbered alternative to Cisco's HSRP. CARP is mostly implemented in BSD operating systems.

Routing Protocols: A routing protocol is a protocol that specifies how routers communicate with each other, disseminating information that enables them to select routes between any two nodes on a computer network, the choice of the route being done by routing algorithms. Each router has a priori knowledge only of networks attached to it directly. A routing protocol shares this information first among immediate neighbors, and then throughout the network. This way, routers gain knowledge of the topology of the network. For a discussion of the concepts behind routing protocols

IGP: An interior gateway protocol (IGP) is a routing protocol that is used to exchange routing information within an organization.

BGP: Border Gateway Protocol (BGP) is the protocol which makes core routing decisions on the Internet; this protocol is used within organizations.