Re: CUSM vs Apple videoconferencing?

Jay Arden Ashcraft (
Fri, 19 May 1995 20:25:20 -0500 (CDT)

On Fri, 19 May 1995, Christer Ericsson wrote:

> How does CU-SeeMe compare to Apples new Quicktime-based videoconferencing
> system due to be functional this summer? Color? yes
>Intrusive alert? Will the
> QuickCam work with Apples system? I understand there are beta versions out,
> so somebody should be able to compare?

the way I understand it, it will be interoperatible with CUSeeMe in time.
the apple rep I spoke to didn't think that CUSeeMe was a competative product
but that QTC is just an extension that will make things all work better
together - perhaps in time

FMI check out the URL:

I am not positive as to the direction of the Cornell team and White Pine
but I bet in long term QTC will be like Sound Manager 3.0, Quicktime,
and MacTCP - just part of the system.

I bet though on the short run it won't work on the older low end boxes.

It may have some network management features. note from Apple documentation:

* Flow Control for Real-Time Media. QTC provides flow control
algorithms which manage network bandwidth when using real-time media
streams. The algorithm will scale the bandwidth of selected media
streams down as the network traffic increases, and will scale selected
streams up if there is little or light traffic on the network. The
scaling techniques consider network performance and maintain audio
quality while concurrently varying video quality, since people are
more sensitive to audio than video quality. Audio data is only
transmitted if the audio energy level is above a certain threshold,
reducing network bandwidth further.

* Multicast Media Distribution. QuickTime Conferencing provides
multicast capability for efficient distribution of media streams on
enterprise networks. Multicast distribution of media means that data
only goes to those machines which request the data, not to all
machines situated on the network. Multicast protocols are an efficient
means to provide media broadcast services, along with multi-party
conferencing on packet-based networks. Apple has developed both a
client- and router-based multicast protocol for use on AppleTalk

* Prioritizing Media Streams within the Network Router: Commercial
routers for enterprise networks often support the notion of traffic
prioritization. QTC data streams can be identified for prioritization
at the network router so that real-time media traffic may be given a
higher (or lower) priority than other types of data traffic flowing
through the router.

* Low Bit Rate Video Coding Algorithms: Apple's H.261 video
compression algorithm can generate video at bit rates as low as
64kbps, relatively low compared to other video coding schemes such as
motion-JPEG, Apple Video and Indeo. The low bit rate of the H.261
coding algorithm will result in a far less detrimental impact on the
network overall, and reduce the impact on network users who may not
require real-time media services.

* Network Administrator Bandwidth Monitoring/Control: An additional
QTC component for network administrators is under development. QTC
will then support bandwidth monitoring and control the bandwidth in
use by QTC applications. Network administrators will be able to set an
end user's maximum bandwidth via SNMP (Simple Network Management
Protocol). If SNMP is not present, QTC's component will use a default
maximum allowed bandwidth to limit the impact on the network.

hope this helps some, check out the URL. I am told it will be out in a few
weeks but not sure what a few weeks means anymore:)

Jay Ashcraft