Agilent Technologies
16741A

Packet switching is a digital network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets.

The network over which packets are transmitted is a shared network which routes each packet independently from all others and allocates transmission resources as needed. The principal goals of packet switching are to optimize utilisation of available link capacity, minimize response times and increase the robustness of communication. When traversing network adapters, switches and other network nodes, packets are buffered and queued, resulting in variable delay and throughput, depending on the traffic load in the network.

Network resources are managed by statistical multiplexing or dynamic bandwidth allocation in which a physical communication channel is effectively divided into an arbitrary number of logical variable-bit-rate channels or data streams. Each logical stream consists of a sequence of packets, which normally are forwarded by a network node asynchronously using first-in, first-out buffering. Alternatively, the packets may be forwarded according to some scheduling discipline for fair queuing or for differentiated or guaranteed quality of service, such as pipeline forwarding or time-driven priority (TDP). Any buffering introduces varying latency and throughput in transmission. In case of a shared physical medium, the packets may be delivered according to some packet-mode multiple access scheme.

Packet Switched Networks are now pervasive as they are being utilised to support core telecommunications, 3G/4G mobile communications and of course LAN/WAN solutions. Extensive testing is required to test all aspects from the physical media through protocol and routing capability to network security.

Livingston provides a range of equipment that can help installers and maintenance engineers and network operators measure and therefore manage their network service levels and performance:

Below is listed some of the equipment that we have available. If you cannot find what you need, please give us a call, as we are very interested in finding the right solution to meet your needs.

For further information please see the following information from two of our key suppliers:

• Ethernet Testing Overview
• Fundamentals of Ethernet
• Metro Ethernet Test