Glossary S, T, U
sFlow - A technology present in some HP switches for monitoring network devices traffic levels.
SFP (Small Form-factor Pluggable) - A hot-swappable input/output device that plugs into a SFP slot on a switch and provides copper or fibre connectivity. In Ethernet systems the speed can be 100Mbp/s and Gigabit.
SFP+ - As SFP but capable of data rate of 10Gbit/s.
SFP28 - As SFP/SFP+ but supporting 25Gbit/s. Typically used to break out from a 100GbE port.
Single Mode Fibre - An optical fibre that carries only one ray of light (a mode) through it.
SNMP - A protocol for managing devices on an IP network for conditions that require administrative attention.
Spanning Tree Protocol (STP) - Sometimes referred to as STP, this is a data link layer protocol that ensures a loop free layout for an Ethernet LAN with the aim of preventing broadcast radiation. See also RPST.
Shielded Twisted Pair (STP) - A type of cable that includes one or more sets of cable pair moulded together by insulating materials and covered with a braided shielding conductor offering better noise protection than Unshielded Twisted Pair.
Stranded - In the context of Ethernet cable, the conductors each consist of multiple strands of copper cable.
SWA Steel Wire Armour - A cable that is armoured providing the highest level of crush resistance and rodent protection meaning that it is suitable for rugged external installations. Compared to CSTA the cable is more flexible but heavier.
Tactical Fibre - Extremely strong and lightweight fibre cable that offers exceptional cut, abrasion and chemical resistance.
Tight Buffered Fibre - A type of fibre cable with includes a polymer coating component used to tightly encapsulate the optical fibres to provide increased protection suitable for both internal and external use.
Twisted Pair A cable with two insulated copper wires twisted together with the twists varied in length to reduce potential signal interference between the pairs.
Uniter - Another name for an adapter which has two female fibre sockets and is used to interconnect two terminated fibre cables.
Unmanaged Switch - A plug and play switch which is desktop or rack mounted, these types of switches have no configuration interfaces or options.
UPS Uninterruptible Power Supply - An electrical apparatus that provides emergency power when the primary power source fails, this switchover is instantaneous and provides protection against business disruption and data loss.
Unshielded Twisted Pair (UTP) - A cable with insulated copper twisted pairs but without any shielding.