Apple VideoPhone

by Pete DeVries (pdevries@wisc.edu)

Have you ever wanted to sit down at a table with a collaborator and discuss a paper or project you have both been working on, but been frustrated because your collaborator is across campus or across the country? New easy-to-use Internet videoconferencing tools are available which allow you to have a work session similar to an across the table meeting with collaborators who are at a distant location

Videoconferencing tools allow you to see and talk with your remote colleague to view and markup graphics and text via a shared whiteboard, as well as exchange files via a shared window. Although some of these tools such as CU-SeeMe have been around for a relatively long time, they have now matured into products which regular computer users will find useful.

Of the products I have studied I find Apple Videophone 1.5 to be the most robust and the easiest to install and use. I was very impressed with the features and performance of VideoPhone 1.5. Not only does it support standard videoconferencing, but the software can also sense the quality of your connection and automatically adjust frame rate and image quality. In addition, it allows you to choose from a wide range of audio and video compressors/decompressors (codecs).

A free version, VideoPhone Lite, which will work with most video cameras, is available from Apple's Web site. They also bundle a more robust version of VideoPhone with a videoconferencing camera for around $250 - a bargain considering the cost of quality videoconferencing cameras. Installation of VideoPhone only took a few minutes on a PowerMac and the product did not conflict with my existing software.

Another consideration for those who require the "video" in conferencing is that your Mac or PC will need a video input port. Connectix makes a serial QuickCam camera, but the video quality and frame rate are limited by the speed of your serial port. A large number of existing and new PowerMac's have built-in video ports including the 6100av, 7100av, 8100av, 7500, 7600, 8500, and 8600.

If your Mac does not have a video input port, or you wish not to be seen by your collaborators, you can choose to audioconference and still use the shared white board and shared files features on any non-Performa PowerMac.

Earlier this year Apple stated that it intends to have a third party take over future development of Macintosh videoconferencing products, although it did not say which third party. With this issue in mind, Dave Rasmussen of Apple Computer and I tested whether the current version of Apple VideoPhone worked with the beta version of Mac OS 8 which is set to ship in July. We found that VideoPhone worked well under Mac OS 8, and actually allowed a faster frame rate than the same machine running System 7.6.1. This suggests that the current version of Apple VideoPhone will remain a viable option for a year or two.

If you already have a compatible PowerMac, a video camera with a video output, and are interested in videoconferencing, I would not hesitate to recommend that you download the free version of Apple VideoPhone Lite from Apple's Web site. If you need a videoconferencing camera then you may want to purchase the Apple VideoPhone bundle. You can use the same camera with other vendors software.

There are several other videoconferencing products available including the cross-platform Connectix VideoPhone and White Pine's Enhanced CU-SeeMe. CU-SeeMe is the best known Internet videoconferencing product. Unfortunately I found version 2.0 of Enhanced CU-SeeMe to be unstable on a PowerMac. White Pine plans to ship a promising new version (3.0) in the next few weeks. I was unable to test cross-platform performance of Connectix VideoPhone and White Pine's Enhanced CU-SeeMe since neither had a version which ran on WindowsNT.

Apple VideoPhone Trials and Requirements

I was able to test Apple Videophone on a local Ethernet network, on an ISDN (Integrated Services Digital Network) connection to the UW-Madison campus, and across the Internet via ISDN. If you want to get the best frame rate while using the least amount of network bandwidth, I would recommend a 150MHz 603/604 PowerMac, System 7.6.1 and Open Open Transport 1.1.2. My test system, a PowerMac 7500 with a 150MHz 604 processor upgrade card, was running System 7.6.1 and Open Transport 1.1.2. Except where noted, my collaborators had the same combination of system software on a PowerMac 8500/150 and PowerMac 6500/250.

VideoPhone Features

In addition to the videoconferencing features, Apple Videophone includes a shared whiteboard where pictures and text can be placed for discussion and markup by both collaborators. There is also a file transfer feature that allows collaborators to exchange files by simply dragging and dropping them into the file transfer window. A chat tool allows users to exchange typed messages instantly. The VideoPhone chat tool is compatible with Netscape's CoolTalk Chat, allowing VideoPhone users to chat with CoolTalk users on other platforms.

Below are some screen shots of videoconference sessions I have tried on a local Ethernet network. Note the two 160x120 pixel videoconferencing windows. These can be enlarged to 320x240 if network bandwidth permits.

Conference Image

Below are examples of the chat tool window and the shared whiteboard. In the shared whiteboard window there is a map which one collaborator has marked up to label a particular location.

Conferencing Image

Below is a shared files transfer window which contains an Excel file. One collaborator simply drops a file in this window. The recipient can drag the file from the shared files window onto the desktop or into a folder. In this way, word processing documents, spreadsheets and other files can be transferred between collaborators.

Shared Files

VideoPhone has a well designed phone book which allows you to store the network addresses of those with whom you collaborate most frequently. It also works with the 411 Internet directory system.

Address Book

VideoPhone over a Local Ethernet LAN

I tried Videophone across a small Ethernet network. Since most of the full Ethernet bandwidth (10 megabits/sec) was available, I was able to test various combinations of settings. I discovered that I could easily videoconference at data rates near 500 kilobits/sec, but a judicious choice of settings allowed me to get usable videoconferencing using only 70-90 kilobits/sec per client. I also later learned that one of the Apple VideoPhone extensions contains a variable which limits the maximum amount of bandwidth that VideoPhone can use to 4.2 megabits/sec.

HIgh Bandwidth Settings
High Bandwith Example Image

Low Bandwidth Settings
Low Bandwith Example Image

VideoPhone over the Internet via ISDN

I also tried Videophone across the Internet with Dave Rasmussen in Minneapolis. We both had ISDN connections to the Internet. Dave was using an Ascend Pipeline 75 ISDN Router with compression and I was using an Ascend Pipeline 50 Router with compression. The videoconferencing, audioconferencing, chat, shared whiteboard and file transfer functions worked well. The data transfer rates suggest that the Ascend's built-in compression allowed us to videoconference using a data rate higher than the standard uncompressed 128 kilobits/sec ISDN connection. As the total traffic on the Internet changed during our experiments the frame rate would adjust automatically. The audio worked pretty well and most of the time we were able to understand each other. There was, however, a slight delay for both audio and video transmission to when it was reception on the other end. This was the result of buffering designed to deal with the variability in Internet traffic. After a short while we quickly adjusted to this lag.

Video Conference Session - Both systems running Mac OS 7.6.1
ISDN Conference Windows 7.6.1

Video Conference Session - Dave's system running beta Mac OS 8
ISDN Conference Windows 7.6.1

VideoPhone to campus via ISDN

I tried Videophone via ISDN to campus with Dave Schroeder in the DoIT Showroom. Dave was on the campus Ethernet using a PowerMac 6500/250 (603e 250MHz). Paul Nazario of DoIT's Network Engineering helped with some of our early experiments and fixed some problems with the ISDN router.

Showroom Session Snapshot

Optimal Settings for two way Ethernet and ISDN videoconferencing

My collaborators and I were also able to determine what we believe are the best settings for connections over either ISDN and Ethernet LANs. Since the campus and Internet bandwidth is a limited shared resource, we determined what settings would give you a usable 10 frames per second and sound with the lowest bandwidth requirements.

Network administrators would be interested to know that the VideoPhone software includes a SNMP (Simple Network Management Protocol) agent that allows them to set limits on how much bandwidth a machine can use for videoconferencing.

You might expect that the connection speed setting when using an ISDN router should be set to ISDN 2B, however, if the router supports compression your actual throughput can exceed ISDN's 128 kilobits/sec bandwidth limitation. You can get even higher frame rates, or lower bandwidth requirements by using the telephone for audio while using VideoPhone for the video, whiteboard and shared files features.

General Settings for Ethernet LANs and ISDN routers which use compression.
LAN Setting

Audio/Video Compressor Settings for Ethernet LANs and ISDN routers which use compression.
LAN Setting

Video only Compressor Settings for Ethernet LANs and ISDN routers which use compression.
LAN without audio Settings

Unidirectional Tests - Sending Video and Audio only one direction

I was also able to experiment with settings that cause one machine to send audio and video while the other machine simply received the transmission. This one-way connection might be used in a tutorial setting or to remotely monitor an experiment. Since only one machine was transmitting, I tried to use a larger frame rate setting of 320x240 pixels. Below are examples from those tests.

Normal Frame Size (160x120)
Small Broadcast Image

Double Frame Size (320x240)
Large Broadcast Image

Unidirectional Settings (Sending Machine)
Broadcast Send Settings

Unidirectional Settings (Receiving Machine)
Broadcast Receiving Settings

During my experiments I had very few problems. Installation took only a few minutes. I was able to switch various settings on the fly. Occasionally one of the compression settings would set itself back to the default, thereby degrading image quality. However, once I became aware of this I just reset the preferences on the fly and regained a good quality image.

In summary, I would recommend Apple Videophone to Mac users who are interested in videoconferencing and remote collaboration. If you already have a camera you can download the VideoPhone Lite software from Apple's Web site. You can also purchase a bundle including a full version of the VideoPhone and a color videoconferencing camera for approximately $250 from the Division of Information Technology's (DoIT) product sales. The bundle is a good value for the price of the camera alone, and the camera will work with videoconferencing software from other vendors if you later decide to purchase Enhanced CU-SeeMe 3.0, Connectix Videophone or some other software product.

Credits: I'd like to thank Dave Rasmussen and Bob Boyle of Apple Computer for helping with tests and lending me a computer. Dave Schroeder and Paul Nazario of the UW-Madison Division of Information Technology (DoIT) for helping with the tests and ISDN configuration.