Babak :
unfortunately, this is not quite true !
The only things you really can do from any PC with net-access are, to change some settings in your account or to initiate transfers. Trading through TWS / JTWS is simply not possible on any PC.
I.e. you can't access TWS or the browser based JTWS through a firewall, unless the admin allows you to connect to IB's secure destination ports by configuring the necessary translation protocols and adresses.( Which he will probably not do in order to follow the companie's internal security guidelines ).
I don't know, why they ( IB ) still stick to this ancient technology. There are better solutions out there to ensure secure connections.
In addition, it's highly unlikely, that you are allowed to download and install any kind of java-plugins on a company computer ( or any other foreign computer for that matter )
Furthermore, the PC has to fulfil certain mandatory minimum standards / settings in order to work properly with TWS / JTWS. Again something, which cannot be assured with just every PC used for internet access. It's also highly unlikely, that you are allowed to change internal settings ( i.e. simply the screen-resolution 1024 x 768 ) on a foreign PC.
Finally, you probably don't know in advance, whether a foreign PC is connected to the net via a proxy-server, and if so, how to configure the settings so that the JTWS works with the proxy.
See also IB's Q&A on these subjects :
"Many high speed Internet service providers have filters or firewalls in place that make it difficult to connect to IB. Please call you Internet service provider and ask them to open the ports displayed below.
The Interactive Brokers' Trader Workstation needs to establish two communication channels to IB's firewall. One of these channels uses TCP and the other uses UDP as the underlying communication protocol. Since the UDP source and destination ports and the TCP destination port is checked for at the firewall, it is the customer's responsibility to set up the necessary translation services (proxies) on his/her firewall as described here.
This data is user specific:
TCP & UDP Source Port: 1024 or higher (if your system needs a Source port)
TCP & UDP Destination Port: 4000
Destination IP address: 208.245.107.3 for gw1.ibllc.com; 208.245.107.4 for gw2.ibllc.com; 208.245.107.5 for gw3.ibllc.com
If you are unsure which IP address you should be connecting to please contact the Help Desk."
and
To connect the Trader Workstation through a proxy server, you should ensure that your proxy server can be configured to assign the following TCP/UDP ports and IP source and destination addresses:
TCP & UDP Source Port: 1024 or higher (if your system requires a Source port)
TCP & UDP Destination Port: 4000
Destination IP address: 208.245.107.3
It is the customer's responsibility to set up the necessary translation services (proxies) on their firewall as described here. Interactive Brokers recommends that you contact your Network support staff for assistance in configuring your TCP/UDP ports."
Conclusion - access to your IB account for trading purposes is simply not possible from "any" PC connected to the net.
This is, imho, one of the few really important disadvantages of IB's tradingsystem. It was almost a year ago, when IB started with this Java-based workstation and these critical issues are still not resolved ( and probably will not anytime soon, since IB insists on it's version of a secure connection system ).
Therefore, I always need to maintain a 2nd. and 3rd. account with other Brokers who offer 24hrs access to my accounts through any PC connected to the web ( these brokers use also secure connections ;can't really understand, what's IB's problem here ).
regards