Yassas.com's platform is built with state-of- the- art Microsoft tools. Microsoft Hellas oversees and supports our new application. Thus, we guarantee you safe transactions, through reliable technology-based solutions

System Architecture
The architecture that is used follows the model of three levels for the platform as well as for the application, in order to secure the continuous availability, uninterrupted operation and ability to upgrade the nod.

Architecture of the Platform
The architecture of the platform made for the development of Internet Systems satisfies in general, the following requirements /specifications:
· Scalability & Extensibility, allowing the easy expansion on application and infrastructure levels (hardware independent platform architecture)
· Interoperability & Integrated Environment, supporting the easy and fast integration, interconnection and communication of the applications into an integrated environment with the use of state-of-the-art technologies (LDAP, etc.) satisfying special claims for personalization
· High Availability, providing unified software and hardware manipulation, reliability and fault-tolerant abilities (error handling and protected subsystems; data and system recovery; Backup support; disk mirroring; disk striping with parity or RAID 5; distributed transaction processing system)
· Load Balancing, permiting the efficient administration / allocation of access and service load of the users in all levels of architecture (web, application, database, etc) and in cooperation with the infrastructure
· Performance, enabling the support of a continually increasing number of users from 5.000, 10.000, etc.
· Manageability, providing an easy to use, operational and integrated environment of management that permits long distance management (through the Web) of the total platform.

Specifically, the basic subsystems provided with the use of Microsoft's platform, are divided on the levels of access, application level and data :

· Access Layer, refers to the central access point of the Internet users and contains the web Server (IIS):
· Web Server, composes the initial access point of users and supports all the internet protocols offering load balancing abilities. It especially provides abilities of HTTP Compression, FTP, Performance enhanced objects, XML, Browser detection, Self Tuning, Security features (Certificate Storage, ΙΡ Restricted access, SSL 3.0, SGC, Digest Authentication, etc.), Multi-site Hosting, Process & Bandwidth Throttling, etc. It is used with the MS Internet Information Server (IIS). In addition it offers the suitable infrastructure for the management of users groups and of their personal information, which will perform the recognition of users when they enter in the system and will operate as a central point of access to the applications and information of the system. The Microsoft platform develops the protocol LDAP v3 and supports different recognition formats (Automatic Cookie, Basic, HTML and Client Certificate Authentication), Dynamic Directory, etc. LDAP will constitute the base for the development of personalized services.
· Application Layer, includes the Application and the Transactions Servers which are necessary for the operation of e-Business applications. Specifically in this case it will use the Microsoft Transaction Server, which is ideal for the efficient management of applications and the support of transactions (end to end transactions) as well as for the development of allotted applications. Concurrently it will use components of the Site Server Commerce Edition for the efficient support of electronic commerce services.
· Data Layer, includes the central point of management for all the information of Yassas.com and constitutes the Database Management System. The system supports a complete users Data Base Management, as well as clustering technologies, scalability, interoperability (database, XML, etc.), free text retrieval, XML views, parallel server options, multithreaded architecture, management tools (tuning, diagnostics, change management, management, monitoring, etc). In this case it uses an MS SQL v7.0 Enterprise Server.

Application Architecture
The application architecture follows the 3-tier development model which divides the application to the following layers:
· Web Access Layer, which includes the access mechanisms (LDAP) through the Web Server of the platform, to the implementation and the Interface of the application using all the necessary technologies (HTML, DHTML, XML, XSL, JavaScript, ASP).
· Application/Transaction Layer, which implements the basic part of the application and operates on the relative application / transaction servers (MTS, Site Server Commerce Edition, etc).
· Data Layer, which refers to the Data Base Management system (MS SQL Server) and supports the management of the power information and applications (SQL, Stored Procedures, XML, etc).