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The client tier is browser based, supporting Internet Explorer 5+ and consisting primarily of JSP generated HTML and JavaScript. Browser-based client architecture was selected in order to provide XIFIN AR users with a "no-deployment" strategy, client hardware independence, and "zero-maintenance"solution. JavaScript is used extensively to maximize data validation on the client in order to minimize network traffic and maximize client performance. For some pages that require a more interactive presentation, Java applets and RMI are used to communicate with the application server. Various HTML/JavaScript based wizards are also being developed to assist users in creating and updating various system components, such as contracts, payors, clients, and patients permanent records.
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The presentation tier is responsible for providing the link between the Client and Business Logic tiers. This is the primary interface to access the XIFIN AR application. XIFIN uses JSP's and servlets to generate HTML for the client tier. JSP's are used to generate the dynamic HTML pages based on the actual data being presented. WebLogic may be configured to operate as the presentation or web server as well as integrate with any other standard server such Apache, Microsoft's Internet Information Server, and Netscape's Enterprise Server. Servlets are primarily used to control client access to the various JSP and static HTML pages throughout XIFIN AR. They are also used to validate all client requests and to cache frequently used information and thereby decrease EJB and database accesses. As a result system performance is increased. |
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The XIFIN AR business logic is being developed entirely in Java, utilizing Enterprise Java Beans (EJB) and servlets to host the many business rules. When transactional integrity is required, EJB's are used to meet this requirement. As one of the benefits of using EJB's, XIFIN AR business objects have the flexibility to be easily configured and deployed on a single or multiple application servers, depending on the client's requirements. If multiple servers are used to implement the business logic tier, the system will support dynamic load balancing for increased performance and fault tolerance by automatically migrating all connections from a failed server to those servers still functioning.
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The XIFIN AR data services tier supports all XA compliant databases, including all major database servers such as Oracle, SQL Server, DB2, and Informix. XIFIN has chosen Oracle as its preferred database because of its proven stability, superior performance, and exceptional manufacturer support. The database design and creation is performed using Computer Associate's Erwin/ERX. Using such a database design tool allows XIFIN to implement the Data Services tier on any XA compliant database. It is also important to note that the Business Logic tier performs all communications with the Data Services tier. This design feature guarantees data integrity and security. |
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XIFIN AR is designed with the highest degree of security in mind. Using industry standard protocols and software, XIFIN AR may be configured as necessary for the environment in which it will reside. The four areas of security addressed are physical security, network communications security, user authentication and access control, and auditing. The physical security of the servers is provided by the co-location facility at three levels: (1) Only authorized personnel are allowed access to the facility, (2) All authorized personnel are escorted at all times, and (3) all XIFIN hardware is secured within locked cages. Network communications security is achieved using router packet filtering and monitored firewalls. All communications and user authentication is implemented using 128-bit SSL encryption. Database security is controlled using Oracle security services. Only a single user ID is setup per client database with each ID having knowledge of and access to only its respective database schema. At the application level, database access can only be performed through a specific client database connection using the specific user ID assigned to that client. DBA access is strictly controlled and monitored by XIFIN's primary and backup system administrators. Application security is controlled using WebLogic Security Services and the JAVA Security API. Access control lists (ACL) are assigned to all WebLogic objects including URL's, files, servlets, EJB's, and database connections. User groups are then assigned to specific ACL's. Finally, users are assigned to specific user groups. User and user group assignment control is performed by pre-authorized end user(s) via a security control screen. Two types of auditing are performed within XIFIN AR: (1) ACL access is logged which provides an audit report as to which user accesses which resources and (2) data auditing is performed logging all record creation and deletions as well as field level modifications. Finally, XIFIN has contracted external security consultants to perform auditing and regular security conformance checking. |
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In the Application Service Provider (ASP) framework, XIFIN has designed XIFIN AR with several redundancies, which will eliminate single points of failure to ensure high system availability. First, we have a cross-connect to the Internet backbone via several Tier 1 providers. Should one of the Tier 1 Internet Service Providers (ISP) connections fail, we will route all of our messages over the remaining connections. Next, our firewall connection to the Internet has a hot fail-over device that can be activated instantly if the primary firewall connection should go off-line. Finally, XIFIN AR runs in a clustered hardware and software environment. This means that there are several Sun Servers with several WebLogic applications running to share the workload, and if either the hardware or software should fail the others will continue to process the workload. |
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XIFIN chose SeeBeyond's E-Gate integration engine because it offers the best solution for applications requiring scalability and large transaction volumes. The following is a description of E-Gate. More can be found about E-Gate and Seebeyond at their website.
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