A new guide to purchasing network equipment published by analyst firm
Gartner aims to help organisations significantly reduce their operational costs and capital expenditure.

The guide analyses what Gartner sees as the three main cycles in the lifetime of network kit: build, operate and dispose. Gartner research vice president Neil Rickard said the middle phase is of particular relevance to network managers “The energy cost of the build and dispose cycle is difficult to quantify, compared with the operate phase,” he explained.

The main message of the guide is for network managers to think before investing in new technologies. Power over Ethernet (PoE), high-specification IP phones and gigabit Ethernet desktop connectivity come under particular scrutiny. “PoE is vital if you’re going to deploy IP phones, but we’ve got clients who are rolling out PoE but have no immediate plans to install IP phones,” Rickard said.

Rickard also questioned the need for organisations to invest in high-specification IP phones. Why buy a top-of-the-line model when all it is going to do is replicate what the PC next to it can do?, he asked. “Most firms only need to use low-spec phones that draw only 5W,” Rickard added.

An easy way for firms to keep their network spending down is to avoid Gigabit Ethernet, according to Rickard. “In most cases Gigabit Ethernet is completely unnecessary, since most people don’t even use 100Mbit/s connections fully,” he said. Gigabit connections typically use 3W-6W per port, rather than 1W-2W with 100Mbit/s. “That’s a tripling of the power consumption for both used and unused ports, because firms typically buy 30 per cent more capacity than they need. If firms deploy thousands of ports, [using 10/100Mbit/s Ethernet rather than Gigabit] represents a big saving,” he added.

The guide also highlights how firms could save capital expenditure by minimising the number of layers in their network architectures. “LAN technology has moved on and a single tier of switches can support more than 1,000 Gigabit ports and tens of 10GbE ports,” Rickard said.

Finally, Gartner urges firms to make power efficiency one of their main product selection criteria. “The difference in power efficiency between the most and least efficient switches on the market, could be between three and five times,” said Rickard.
Summing up the guide’s key findings, Rickard said, “Say Company A followed our recommendations while Company B bought Gigabit PoE switches, architected its network with lots of layers and chose kit without any environmental considerations in mind, then the difference in energy costs between these two slightly excessive extremes could be ten-fold.”