Feeds

Time to turn on to power over Ethernet?

Old idea, new energy

  • alert
  • submit to reddit

Internet Security Threat Report 2014

Quocirca’s changing channels With the uptake of IP telephony continuing apace and the proliferation of IP devices in general, has the time finally arrived for an old concept – power over Ethernet (PoE)? For certain deployments of IP based technology, PoE is not only cost effective but arguably essential.

IP enabled devices like telephones and surveillance cameras that are always on need power, and power means cables. So although most IP devices have the potential to attach to a wireless data network, they can never be truly wireless because of the need for power.

But for such devices the power requirements are low. Low enough that just like traditional telephones, both the power and service can be provided by the same cable. This is the concept behind PoE – delivery of low voltage power to a device over a standard Ethernet data cable.

This is not a new concept, the idea has been around for years, but take up has been limited. One reason for this has been the lack of standards, but this has changed. The 802.3af standard, agreed a few years ago, is now being widely adopted. Cisco, the leading supplier of data networking products and a major supplier of IP devices, switched from its own proprietary way of doing things soon after the standard was introduced, and many other vendors have now followed suit. This allows for interoperability between different products, allowing resellers to put together proposals based on components from a range of suppliers.

Another reason for the slow uptake has been lack of applications, but this too is changing fast, largely driven by the take up of IP telephony. On the surface this would seem an unlikely driver as most IP phones will be on desktops and desktops have power – if the phone needs power, just plug it in.

But there are two reasons that make PoE attractive for IP telephony. First not all phones are on desktops, they are also in meeting rooms, corridors, store rooms etc. Sometimes they are in places where a convenient power socket may not be available. With PoE this is not a big problem; unlike high voltage mains supply, IT staff can install Ethernet cable.

However, there is another more compelling reason. Telephones need to work in an emergency including when there is a power failure. Traditional telephones do, but IP phones will only do so if there is an uninterrupted power supply (UPS). The only practical way of guaranteeing power supply to a large number of IP phones is PoE.

Enabling PoE requires network switches or routers that have been built to handle both data and power supply and these can be powered by a UPS. The cost of upgrading or replacing existing switches and routers can be high making the introduction of PoE prohibitive and driving up the cost of IP telephony implementations. But even if the cost of upgrade or replacement cannot be justified there is an alternative.

So called ‘midspan’ devices from vendors like PowerDsine are about one tenth the cost of a traditional switch and can draw power from the mains and data from a switch or router and feed into a single Ethernet cable. Of course, they too need a UPS if power is to be maintained during an outage.

The most compelling reason for enabling PoE is IP telephony, but once it is in place other applications become more practical to implement. IP surveillance cameras are pretty cheap now and capable of being powered by Ethernet. Wireless access points themselves can be powered by Ethernet; they have to have a data connection and their placement is more flexible if it is also their source of power.

Standardisation and new technology have made PoE a more practical proposition, but it will be business take up of IP based applications that will justify the cost. Once enabling PoE has been put in place for an initial project other opportunities open up.

© Quocirca

Bob Tarzey is a service director at Quocirca focussed on the route to market for IT products and services in Europe. Quocirca is a UK-based perceptional research and analysis firm with a focus on the European market.

Related stories

Ethernet forum plots death of SONET

Internet Security Threat Report 2014

More from The Register

next story
Docker's app containers are coming to Windows Server, says Microsoft
MS chases app deployment speeds already enjoyed by Linux devs
IBM storage revenues sink: 'We are disappointed,' says CEO
Time to put the storage biz up for sale?
'Hmm, why CAN'T I run a water pipe through that rack of media servers?'
Leaving Las Vegas for Armenia kludging and Dubai dune bashing
'Urika': Cray unveils new 1,500-core big data crunching monster
6TB of DRAM, 38TB of SSD flash and 120TB of disk storage
Facebook slurps 'paste sites' for STOLEN passwords, sprinkles on hash and salt
Zuck's ad empire DOESN'T see details in plain text. Phew!
SDI wars: WTF is software defined infrastructure?
This time we play for ALL the marbles
Windows 10: Forget Cloudobile, put Security and Privacy First
But - dammit - It would be insane to say 'don't collect, because NSA'
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Cloud and hybrid-cloud data protection for VMware
Learn how quick and easy it is to configure backups and perform restores for VMware environments.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.