In addition, some VoIP solutions do not require you cut the cord to your PSTN. NEC supplies IP PBXs so enterprises can phase in VoIP (see "PBXs Make Room for IP, UM Services").

Cables and Bandwidth

Bandwidth requirements for streaming media and VoIP might put heavy demands on your network and a damper on wide-area convergence. But the falling price of broadband will bring fiber to an increasing number of businesses. In fact, Ernst & Young predicts that by 2004 80 percent of large companies and 54 percent of midsize businesses (defined as companies with 100 to 499 employees) will have fiber links.

If fiber is not in your immediate future, you can rely on other convergence technologies, such as caching and content delivery, can deliver rich media over WANs (see "CacheFlow Security Gateway Ain't Your Pappy's Cache"). And content-aware switches, like the F5 Networks' Big-IP 5000, and Layer 4 switches, like 3Com's SuperStack 3 4400, can enforce QoS policies on LANs. Moving up the stack, Layer 5 enterprise switches work with a variety of H.323 gateways to put multimedia packets at the head of an access queue, reducing latency and jitter (see "Tuning Voice Over the WAN").

A Rush of Streaming Media

The use of video over IP-based networks has been increasing. Companies are cutting back on travel by using videoconferencing, and using IP video cameras for security. Apple has been at the forefront of streaming video--its QuickTime Streaming Server won our Well-Connected award in this category.

Although software solutions are a good fit for most, if your streaming needs require full-screen, full-motion video you'll need dedicated hardware (see "Hardware or Software: Wading the Video Stream"). We tested equipment from Amnis Systems, Minerva Networks and VBrick to view full-screen, high-resolution and 30-fps (frames per second) video over wide-area Ethernet. These hardware encoders and decoders trounce software solutions when it comes to quality.

All this leads to the holy grail of streaming video: DVD-quality content over IP. As compression technologies improve, broadcast-quality video sent to the home or office will become a reality--without expensive decoders or high-bandwidth connections.

Special Delivery

Content-delivery service providers continue to add value to e-business initiatives at the edges of public networks. Using overlay networks of distributed servers in ISP PoPs (Points of Presence), Akamai, Digital Island, Speedera and others mirror content owned by subscribers and serve it to users on demand without traversing the Internet to origin servers. The Aberdeen Group says this market segment will grow to $703 million by 2005.

We're seeing some indication of this growth as new players--including Web hosting provider Conxion and digital-media provider Kontiki--vie for a slice of the pie. But this is a difficult market for newbies to crack: An established customer base with cash and content to deliver is crucial, and the cash and content are in the enterprise. Akamai knows this and is taking its EdgeSuite service and ESI (Edge Side Include) technology to this market with EnterpriseSuite. It delivers HTTP- and file-based content to users from the closest available edge node while supporting both unicast and multicast live streaming.

Among established vendors, Cisco has bootstrapped its Content Edge Delivery Devices with the credit it's earned as an infrastructure provider. It also relies on its WCCP (Web Cache Communication Protocol)-enabled devices to redirect Web traffic to cache servers transparently. Network Appliance supplies an end-to-end solution, moving content from back-end storage devices to front-end caching units near users. Volera's Velocity CDN makes use of its caching technology in Excelerator. The same is true for CacheFlow's cIQ Director and Security Gateway Appliance.

But not everyone relies on cache and credit. InfoLibria's Content Operating System and Rich Media Starter Kit received our Well-Connected award (see "Infolibria Rich Media Starter Kit Takes Command of Streaming Media"). That solution delivers rich media from origin servers to MediaMalls close to users. Although InfoLibria's product does not work with existing infrastructures--Cisco's does--and lacks its own back-end storage device--Network Appliance's has one--MediaMalls work with applications that create content.

Standards Fare

OK, so there are good business reasons to implement VoIP, but are products interoperable? Yes and no. Many products adhere to H.323 signaling technology, but that uses a slow, complex call-setup routine. Although H.323 version 3 for VoIP speeds call setup and defines audio, video and data communications over packet networks, many vendors aren't past version 2. And even if they are up to version 3, call setup is still a complex process involving seven major protocols, including audio/video codecs and call/control signaling.

SIP (Session Information Protocol) reduces VoIP complexity and should be on anyone's shortlist of requirements for gateways, routers and IP phones. SIP simplifies call setup and release using a text-based protocol. SIP is an open architecture that can be implemented with PERL and Java.

Sean Doherty is a technology editor and lawyer based at our Syracuse University Real-World Labs®. A former project manager and IT engineer at Syracuse University, he helped develop centrally supported applications and storage systems. Send your comments on this article to him at sdoherty@nwc.com.