The main TANGO Interactive applet (Session Manager) is ~200 KB for Netscape and ~112 KB for Internet Explorer. This is not much - an everage GIF or JPG slide produced by PowerPoint is approximately in the same size range. In addition to the code, TI system must access several configuration and small image files on the server before it starts. These files add some 30 KB.

With this size, the code download time to the browser varies from 40 seconds for Internet Explorer (65 seconds for Netscape) on a slow 28kB modem, to 9 seconds for IE (15 seconds for Netscape)  on a 2-channel ISDN. Download times over LAN can vary, but will typically be approx. only 50% of the ISDN time.

The actual system startup times can be shorter or longer, as explained below:

207678

Tango Interactive Virtual Meeting startup times, in seconds:

Machine: a 300 MHz Pentium II PC under Windows NT 4.0

Connection

First load ever

First load after browser start

Subsequent loads

64 kpbs ISDN

IE: 62, N: 158

IE: 17, N: 145

IE: 8, N: 35

128 kpbs ISDN

IE: 40, N: 140

IE: 15, N:  90

IE: 6, N: 24

LAN

TBD

TBD

TBD

Machine: a 550 MHz Pentium III PC under Windows NT 4.0

Connection

First load ever

First load after browser start

Subsequent loads

LAN

TBD

TBD

TBD

All numbers are in seconds, for Internet Explorer (IE) and Netscape (N), respectively. "First load ever" corresponds to the first TI startup after our plugin software has been installed. This time is the longest, as there is no benefit of file caching and local installation (Internet Explorer). After the system has been used at least once, all subsequent startups will be shorter, especially for Internet Explorer. "First load after browser start" corresponds to first TI system startup after the browser has been (re)started. Restart of the TI system in a working browser is very fast, even in Netscape.

System startups in Internet Explorer are dramatically shorter as compared to Netscape. This difference is caused by two factors: generally more efficient byte code checking in the IE Java VM, as well as the IE ability to treat certain external Java libraries is "trusted code". TI system extensively uses Swing libraries from Sun. These libraries are installed on the client machine during plugin installation. With IE, they are verified ONCE and then treated as trusted code. Netscape browser runs the byte code checking procedure on the Swing library every time the library is activated the first time after browser startup. Swing library byte code  checking procedure accounts for ~75% of the system startup time in Netscape.

Since the system startup is a CPU-intensive operation, it gets shorter on faster machines. On a state-of-the-art PCs TI system startups is almost instantenous.On the other hand, on Unix machine the startup can take up to 5 minutes.

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