HL7Connect Technical Specifications

HL7Connect is a fully featured HL7 messaging Interface Engine that passes HL7 messages between HL7 compliant applications, removing the need for applications to interface directly.

HL7Connect supports interfacing via several transport protocols and provides support for message translation using Javascript and VBScript.

HL7Connect runs as a service on Windows 2000/XP/Server 2003.
Windows 95/98/ME/NT is not supported.

Data is stored in a SQL compliant database, in a choice of database systems.
Administration and monitoring of HL7Connect is performed via a web browser.

Important note on DEP (Data Execution Prevention):

Newer sytems have the option of using hardware DEP to prevent applications launching "malicious" code.
This can cause HL7Connect to have access violations when attempting to run the first line of any script.

Answers.com has the following information on DEP:

"Data Execution Prevention (DEP) is a Microsoft feature intended to prevent a Windows PC from executing code from a non-executable memory region. This helps prevent certain exploits that store code via a buffer overflow, for example. DEP runs in two modes: software-enforced DEP with a limited prevention for CPUs that do not have hardware support; and hardware-enforced DEP for CPUs that can mark memory pages as nonexecutable. Hardware-enforced DEP enables the NX bit. DEP is a feature in Windows XP Service Pack 2, Windows XP Tablet PC Edition 2005, and Windows Server 2003 Service Pack 1. This article describes hardware-enforced DEP. It works by marking certain parts of memory as being intended to hold only data, which the NX bit enabled processor then understands to not be executable. This helps prevents buffer overflow attacks from succeeding. In some instances, Data Execution Prevention can have the unintended consequence of preventing legitimate software from executing. In these cases, the affected software needs to be flagged as being allowed to execute code in those parts of memory, but this itself leads to a possible attack.

http://support.microsoft.com/kb/875352/EN-US/"

This will impact HL7Connect launching scripts.

To check your DEP settings:

1. Click Start, click Control Panel, and then double-click System.
2. Click the Advanced tab. Then, under Performance, click Settings.
3. Click the Data Execution Prevention tab (if available)
4. Click Turn on DEP for all programs and services except those I select to select the "OptOut" policy.
5. If you selected the OptOut policy, click Add and add the applications that you do not want to use DEP with (add HL7Connect.exe)

The above is based on the following information:
http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2mempr.mspx

Restart the computer to get the change.

---

Technical Summaryy

.: Transport Layers

• TCP/IP - The HL7 Minimal Lower Layer Protocol (MLLP)
• File - File-based interaction using HL7 messages or Plain Text Files
• HTTP - Encrypted Message exchange using HTTP/1.1 protocol
• Email - Encrypted Message exchange using SMTP/POP
• DLL - Use a custom Windows .dll to provide the message transport

.: Hardware Requirements

The hardware requirements for HL7Connect will vary greatly depending on the throughput of messages, and the interface configuration. Disk storage depends on how many messages are received, and how long messages are stored in the database. The minimum requirements for a small installation of HL7Connect, with few interfaces and low message traffic would be:

• Intel Processor(s)
• 32MB RAM

As the scale on which HL7Connect is being used increases, correspondingly so do it's hardware requirements. If HL7Connect is being installed on a Windows 2000 workstation, as an Enterprise HL7 Interface Engine, then the system should include the following specifications:

• Intel 1000MHz +
• Windows 2000/XP/Sever 2003
• 512 MB RAM

.: Databases

• Microsoft SQL Server - Versions 6.5 – 2000.
• MySQL - Version 4.1.8+
• Interbase - Version 6 (Open source)
• Sybase Enterprise Server - Versions 11.5 – 12
• DBISAM - Inbuilt database when RDBMS not available.

.: Scripting Languages

• JScript - Microsoft Implementation of Javascript
• VBScript - Microsoft Visual Basic for Applications

.: Browsers

• Internet Explorer - Version 4+
• Mozilla Firefox - Version 1.0+
• Netscape Navigator - Version 6+

.: Encryption

TripleDES (3DES) encryption with Cipher Block Chaining (CBC) across messages.

Private

• Internal - Sender and Receiver use a common Secret Key

PKI

• X 509 (Windows) - Sender and Receiver agree on a Microsoft Windows Certificate to use
• PGP - Sender and Receiver agree on a PGP Key pair to use

Microsoft Certificate handling systems or PGP needs to be fully installed to use PKI

SSL

• Support for SSL certificates