Selecting a H.323 Codec

Recommended models:

The following videoconference sytems are recommended when purchasing a new codec to provide maximimum compatability with WA-K20 Videoconference Services. We have selected models that have a wide variety of features and add-ons available to meet the needs of most videoconference users.

WA-K20 has incorporated Polycom Multipoint Control Units (MCU or "video bridge"). Purchasing Polycom codecs will provide maximum compatibility with the MCUs. As codec software upgrades become available, the codecs need to stay compatible with the MCUs, and vice versa. Upgrades are more synchronized within the same manufacturer. Codecs from other manufacturers should be compatible also as long as they comply with ITU H.320 or H.323 standards. At the NCESD, we have several Polycom units to use and test.

1. Integrated or Fixed Classroom:
• HDX 9000 series A high definition appliance. These codecs support resolutions up to 4CIF (704x576 pixels) at lower bandwidths (i.e., 384K) and will also support 720p (High Definition, 16:9 ratio, 1280 pixels horizontal, 720 lines vertical). Coming in second half of 2007 will be 1080i (1920 pixels horizontal and 1080 lines vertical) support. These codecs can be integrated into a classroom or used in a rollabout cart.
  
• VSX8000 series A rack mounted appliance designed for integration into a classroom. It has multiple inputs and outputs for interfacing with classroom cameras, monitors and control systems and supports People+Content (video plus XGA graphics sharing).
  
2. Roll About:
   • HDX 8000 series A high definition appliance that is similar to the HDX 9000, except it is a TV set-top appliance which includes one camera. The codec system can be purchased separately and used with an existing s-video enabled TV and cart or the whole package with cart and TV.
     
   • VSX 7000 A great entry-level set-top model for medium to large classrooms. It has options that supports H.264, People+Content and multipoint built-in. It does not have options for audio call add-on or streaming.
     
   • V500 A set-top, designed for a small group (1-4 people), sits on top of a TV or LCD monitor, like the VSX7000, except it is smaller and has less capabilities. Includes microphone and camera that can be moved manually only.
     
3. Desktop/Personal Systems:
   • PVX software based application works with the Polycom ViaVideo hardware or many models of USB-based web cameras. It is software that can be installed on a PC desktop or laptop (it is not available for Macintosh computers). This system is not designed for classroom-size conferences, it is best used for 1-2 people.
     
   • Macintosh software
     
4. Full Manufacturer Product Lines:
   • Polycom
   • Tandberg
   • VCON
   • Sony

"Appliance" codecs vs. computer-based codecs:

Appliance codecs do not run on Microsoft Windows™ and tend to not be targeted by Internet viruses and worms. This fact alone saves unmeasurable staff time. They can be placed safely outside the firewall. Non-appliance endpoints really need a firewall upstream, which adds to the challenges of using H.323. See Firewalls

Consider the faster reboot time of an appliance compared to a Windows-based codec. Every minute, every second counts when you are waiting for a codec to reboot.

Maintenance Plans:

We recommend you purchase a maintenance plan with your codec. It will be required for software upgrades as well as repair or swapping if it breaks down. We purchase the three year premium plan, its that important to us to keep the system updated and working. The vendor can discuss the details with you.

Purchasing a codec:

If you are replacing or adding videoconference equipment, our technical staff is available to assist you in determining the best solution to meet your district's needs. Polycom equipment is available on the 2006 Instructional Technology Bid.

Vendors to contact:

Consult these vendors for details and other Polycom equipment and peripherals:

~Exerpts for the material on this page have been graciously contributed by Wisconsin VCS Videoconference Services