Library items tagged: H.323

Local area networks of any significant size, which almost certainly encompasses all those at educational organisations, are complex and unpredictable systems. The traffic flows produced within these networks, and the interactions between different flows within network components such as switches, are highly complex. Classifying, policing and priority queuing allow the network administrator some control over how these flows transit the network, and – crucially for voice and video traffic – allow time-critical traffic to have priority over other, less time-sensitive traffic.

Layer 1 - The Physical Layer Most modern campuses have installed switched networks but there remain sections of some networks that have hubs or co-axial cabling with repeaters. Because these networks are built on protocols that accept collisions, and hence congestion, as a normal part of network life, their traffic forwarding algorithms will back off from sending frames in the face of congestion.

NAT should be familiar to network managers – it is widely deployed in large private networks. NAT is described fully in RFC1918 “Address Allocation for Private Internets”. NAT was introduced partly as a means of conserving real or public (also sometimes called 'routable') IP addresses. The deployment of NAT allows large organisations to give every computer a unique Internet address without diminishing the available pool of public IP addresses.