Data passing between tiers

Hi, i need little help for a project..let me give little backround information...i am working for a company and we built a applicatin that all the big companies who run all thier pc's behind the very secure firewall. i don;t know that much about the firewalls and i don't what technology i can use to build a web site that acccesebile from all these companies...this where i need help...i am sure i will use asp.net 2.0 but i am not sure why do i need to use web services , i think i can build the web site just using direct sql connectionstrings to access the database so please answer these for me ; 1 - if i use direct sql connection strings to acces the database ,is the web site still can be accessible from those big companies who run behind the firewalls ? 2- why is should use the web services ? ( i know they run from open ports ( port 80 or 8080)) 3- what is the other technologies that i can use ? 4- where can use the JSON in this architucture ? 5- can you draw a diagram to show all the tiers ? any question are welcomed . P.s : my company or the customers , either of us can NOT open access in their firewall to IP's becase of the strict security issues...so soutions must be based on this rule. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform will be windows .