Problems across our organisation

Hi all,

Newbie here so go easy on me...

One of our teams at work is receiving training from a 3rd party company that delivers its material via Adobe Connect webinars.  We are having great difficulty in receiving them, with multiple users having the webinar load, play a few seconds (always less than 10, usually 3 seconds) then simply freeze.  After about 30 seconds in which it looks “paused” , the main video feed shows as a black box and the presentation slides disappear. 

All users have at least 512Mb RAM (most 1 or 2GB, some with more); 90% are using IE7, some IE8; every user has at least 1.4GHz Intel Pentium 4 processor (majority have Core2Duo – some have i3/i5). Again, 90% are on XP, some are on 7 (all Windows OS) – all however are running a custom, in house build.  Flash Player & Connect plugins are the latest available. 

We also have 2 connections; our main domain enterprise which uses proxies to connect and which all users outside of the IS dept. connect using.  The connection supports approximately 80 users at our head office & is a 100meg leased line.  We also have a standard ADSL connection which is used for a wireless LAN – this is only accessible to IS staff.

Some PCs can connect and watch webinars fine either on the LAN or wireless.  For others it only seems to work on the wireless, for others it only works on the LAN.  For a final few it doesn’t work on either.

The WLAN has no access/distribution layer switches behind the access point; it is literally a copper pair into the filter, then into the router – i.e. it completely resembles a residential network. i.e. there are no proxies, firewalls, traffic policing or other forms of QoS.  This is a 2Mb connection & when tested was done so 1 machine at a time.

Can anybody suggest why this maybe happening?  The fault looks just like it is buffering the video – i.e. frozen picture and a loading circle.  What is the likelihood of this being an issue at the hosts end?  Are there any known errors which we should be aware of?

Thanks in advance for replies