Home » Magazine Archives » March 2008
Security Technology Executive
Most Read
Most Emailed
E-mail Article
Print Article
Convergence Q&A
Planning for PoEThe Latest from SIW
Mace to launch dealer program, acquire central station Basics of establishing an employee ID badging system The security week that was: 1/02/09 The top 40 security stories of 2008 Homemade bombs force evacuations in Aspen, Colo. Toronto wraps up municipal surveillance pilot project
By Ray Bernard, PSP, CHS III
Security Technology & Design
Responses to this column’s questions about challenges relating to technology convergence indicate that Power over Ethernet (PoE) warrants special attention. Many companies are updating their network infrastructures with PoE capability for IP telephones, providing an infrastructure that is compatible with IP cameras, also known as network cameras, that are PoE-enabled. This is good news for security in such companies, but to benefit (and to avoid unnecessary expenditures) Security must collaborate with IT early in the network upgrade planning.
Wikipedia (the free online encyclopedia) provides a good article on Power over Ethernet that begins with a good descriptive definition: http://en.wikipedia.org/wiki/Power_over_Ethernet. The Security Industry Association (SIA) made PoE the subject of one of its Quarterly Technical Updates. The update from Koffel Associates is co-authored by Shayne Bates, principal, Security Consulting at Koffel. It is available at poe.koffel.com.
The current PoE specification (802.3af) limits PoE supplied power to 15 watts at 48 volts. An update to the specification (802.3at) is almost complete and will double the power to 30 watts at 24 volts. This will allow support for devices such as PTZ cameras, which require more than 15 watts of power.
IP Telephones combine Voice over IP (VoIP) and PoE technologies, and use a single PoE-enabled network connection for both power and data, which can be used for voice data alone or for voice plus video data (IP video phones are already here).
Early collaboration with IT is important if your company is upgrading for IP telephones, and you’d like to take advantage of the network for IP video. Such newly upgraded network infrastructure will be compatible with PoE-enabled network cameras, but that doesn’t mean that the network’s PoE power capacity will be sufficient to support an array of network cameras. Arranging that capacity in advance is generally much less expensive and troublesome than arranging it after IT’s network upgrade is done.
For example, the price difference between a network switch configured to support only the planned IP telephones, and one that supports the phones plus 25 cameras, would be in the neighborhood of $500 at the time of original planning — and the procurement and deployment costs would be part of the existing IT budget. However, the full cost to upgrade afterwards (i.e. after the IT project is complete) could be $3,000 to $5,000 per switch, with security having to foot the bill for the after-the-fact upgrade to power the cameras.
Here are two of the answers on this topic that shed light on some current and future aspects of placing PoE-enabled security devices onto a corporate network.
