What the future holds for corporate voice telephony via WLAN
Published: 28 Jun 2004 12:05 BST
What You Need to Know
An organisation that combines separate strategies for IP telephony and wireless and wired LANs into a single comprehensive plan will reduce its costs. It will also establish the basis for a more flexible architecture. Network managers should take this into account before buying new equipment, but recognize that, until 2008, supporting IP voice calls over wireless LANs may only be cost-effective for organizations in specific industries and for some small offices. They must carefully weigh the benefits of providing this voice support against the extra cost it entails.
Analysis
Voice and data traffic, and wired and wireless LANs are converging.
Network managers in most organisations that don't already have wireless LANs (WLANs) are planning to install them in office buildings. This type of network is becoming a mainstream technology.
As WLANs develop from second-generation access point architectures into their third generation, the "intelligence" in them is moving toward the edge, or even the core, of organisations' wired LANs. Mid-sized and large WLAN installations also have implications for wired LANs because they impose additional requirements on management systems, security and switches.
At the same time as organisations plan to deploy WLANs, it's often the case that IT managers in the same organisations are considering upgrading wired LANs to handle both voice and data traffic during the next two or three years. Significantly, most organisations' wired infrastructure will need upgrading to support IP telephony. This entails adding redundancy features, emergency power, Power over Ethernet (PoE) and quality-of-service (QOS) protection for voice traffic. Security may also have to be revised.
Currently, most purchases of PBX lines are for non-IP fixed handsets connected through a gateway to an IP-enabled PBX. PBX lines serving IP client devices account for less than a tenth of the lines in use. But this situation is changing fast. By 2009, over half the world's PBX user terminations will support IP.
Given the complexity of this situation, it makes sense for network managers to combine their strategies for WLANs, wired LANs and IP telephony into a single comprehensive plan for a cost-effective and flexible infrastructure. At the very least, they need an integrated plan for equipment purchasing. Those without one will have to rebuild their networks several times to add WLAN and IP telephony capabilities.















