Service Advertisement Protocol. In IPX networks, SAP is the protocol that disseminates information about what servers provide which services.
Synchronous Data Link Control. This serial protocol was developed by IBM for use with SNA.
See SAP.
There are two general types of fiber optic cable—multimode and single mode. Single mode is capable of supporting light signals from only a narrow range of wavelengths. This means that it must operate with a more expensive higher-powered laser device to inject the signal, since these devices have a nearly pure, single-wavelength light output. The higher costs coupled with higher power requirements means that single mode fiber is perfectly suited to longer distances such as those in a campus or Metropolitan Area Network.
Serial Line Internet Protocol. SLIP is a standard for running IP over low-speed serial lines.
Systems Network Architecture. SNA is a set of protocols developed by IBM.
Sub-Network Access Protocol. Defined in IEEE 802.2, SNAP is a Logical Link Control protocol that is used with Ethernet and Token Ring systems.
Simple Network Management Protocol. SNMP is a standard network-management protocol that provides the ability to monitor and configure network devices, as well as send alerts.
Synchronous Optical Network. SONET is a high-speed optical-network architecture that is commonly used in Metropolitan Area Networks.
A protocol and algorithm for ensuring that redundant Layer 2 connections are free from loops. Spanning Tree also enables backup links when primary links fail.
In dynamic routing protocols, refers to the constraint that devices should not send the same routing information back to the device from which they originally received that information.
Sequenced Packet Exchange. In the Novell IPX protocol, SPX is a connection-based Layer 4 protocol.
As a basic network topology, represents the configuration where many devices all connect to a single central device. This configuration is also sometimes called Hub and Spoke.
Shielded Twisted Pair. A type of cabling in each run of cable contains a bundle of several strands of copper wire. The individual strands are separately insulated and are twisted around one another in pairs to improve the electrical impedance characteristics. The entire bundle is wrapped in a conducting sheath to provide further protection against electromagnetic radiation. See also UTP.
In IP networking, a contiguous group of addresses that represent a logical subset of a larger network. Subnet addresses are formed by combining the IP address for the larger network with a netmask to define the contiguous smaller range. See also Supernet.
See SNAP.
Similar to a subnet except that, instead of subdividing larger network numbers, a supernet consists of several contiguous networks joined together by means of a common netmask. See also Subnet.
Switched Virtual Circuit. In many packet- switching networks such as ATM and Frame Relay, logical connections called Virtual Circuits are set up between end point devices. If this Virtual Circuit is dynamically set up and torn down by the network, it is called an SVC.
A Layer 2 device that connects different Layer 1 or 2 network domains. It forwards frames between these different network domains based on Layer 2 addressing information. Many switches are capable of grouping these domains into VLANs.