IB Computer Science Topic A2.3: Data Transmissions Key Definitions

Attenuation is the loss of signal strength as a signal travels through a transmission medium. It sets how far a link can run before the signal has to be regenerated by a repeater or a switch.

Bandwidth is the maximum amount of data a link can carry per second, usually measured in bits per second. On a shared medium such as wireless it is divided between all the devices using the same channel.

Convergence is the period after a network change during which routers exchange updates until every routing table holds a consistent view of the network.

Dynamic routing is a method in which routers run a routing protocol to discover routes and recalculate them automatically when the network changes.

An IP address is the numerical label given to a device on a network, carried as the source and destination fields in the header of every packet. Routers read the destination field to decide where to forward the packet next.

Network address translation (NAT) is the process by which a router rewrites the private source address of an outgoing packet to its own public address, records the swap with a port number, and reverses the rewrite on the reply. It lets many private devices share one public IP address.

Packet switching is a method of transmitting data by dividing it into smaller units called packets.

Routers are devices that direct data packets between networks. They determine the optimal path for data transmission using routing protocols and routing tables.

Routing table is the list a router holds of destination networks and, for each one, the next hop address or exit interface used to reach it.

Static routing is a method in which an administrator enters every route into each router manually, so the entries change only when a person edits them.