NAS services are a middle-tier server component that executes business logic without a user interface or user interaction. NAS services in Microsoft Dynamics NAV Server support applications such as Microsoft Office Outlook Integration and the NAV Job Queue.

NAS stands for NAV Application Server, which was a component in earlier versions of Microsoft Dynamics NAV. NAS services replace the NAS component, and this requires you to modify any use of server-side COM. For more information, see Extending Microsoft Dynamics NAV Using Microsoft .NET Framework Interoperability.

Run NAS Services Applications in Dedicated Server Instances

It is recommended that you create a separate Microsoft Dynamics NAV Server instance for each NAS services application. See How to: Create a Microsoft Dynamics NAV Server Instance.

There are multiple reasons for running NAS services sessions in dedicated Microsoft Dynamics NAV Server instances:

  • Efficiency and convenience
    When you change any Microsoft Dynamics NAV Server setting, you must restart the instance for the change to take effect, which interrupts all services using that instance. So if you are running different types of services in the same instanceófor example, RoleTailored client services and NAS servicesómaking a change to the settings for either service type will require a server instance restart that interrupts all other service types running through that instance.
    Even for different types of NAS services applications itís wise to run each application in a separate server instance. For example, if you will be using NAS services for a Microsoft Office Outlook Integration application and also for a Microsoft Dynamics NAV job queue application, create a separate Microsoft Dynamics NAV Server instance for each NAS services application. This way, if you need to modify settings for the Microsoft Office Outlook Integration application you will not affect the Microsoft Dynamics NAV job queue application, and vice-versa.
  • Performance
    Configuring NAS services applications to use separate server instances makes better use of the server computerís resources, allowing you to run more applications with less degradation.
  • Efficient error tracking
    If a NAS services session terminates in an error, and there are no other services running on the Microsoft Dynamics NAV Server instance, the service instance terminates and can be handled like any other Windows service. For example, you could configure the Recovery tab on the Service configuration tool in Control Panel to restart or otherwise manage the service.

NAS Services Settings

You configure NAS services using the settings in Microsoft Dynamics NAV Server Administration tool.

On the General tab, the Services Default Company specifies the default company that is used by NAS Services as well as other types of client connections.

The following settings are available on the NAS Services tab:

Field Description

Enable Debugging

Specifies if the Microsoft Dynamics NAV Debugger must attach to the NAS Services session. When this is enabled, the NAS Services session waits 60 seconds before the first C/AL statement is run.

Retry Attempts Per Day

Specifies the maximum number of times that a Microsoft Dynamics NAV NAS Service session can restart after a failure. After the next failure, the NAS Service session stops.

Startup Argument

Specifies a string argument to be used when NAS services start. The argument typically specifies an application type, sometimes with additional configuration information.


  • "OSYNCH"

Startup Codeunit

Specifies the codeunit that contains the method that will be called by the NAS Startup Method.

Example values:

  • 0
    When NAS Startup Codeunit is set to 0, NAS Services do not start. This is the default value.
  • 1
    When NAS services start they run the trigger specified by the NAS Startup Method in codeunit 1.
  • 450
    When NAS services start they run codeunit 450 (Job Queue - NAS Start Up), and call the method specified by NAS Startup Method.
    When the NAS Startup Codeunit is a single instance codeunit, the NAS services session will remain alive even after executing all code in the specified NAS Startup Method. For information on single instance codeunits, see Using Codeunits.

Startup Method

Specifies the method that will be called in the NAS Startup Codeunit.

Example values:

  • ""
    If no start method is specified (null string), the OnRun trigger is called.
  • StartNAS
    NAS services runs the StartNAS method in the NAS Startup Codeunit.

NAS services sessions execute in the time zone specified by the ServicesDefaultTimeZone parameter for Microsoft Dynamics NAV Server. See Configuring Microsoft Dynamics NAV Server for details on this parameter.

NAS Services and Languages

In multilanguage deployments of Microsoft Dynamics NAV, the language preferences and regional settings for the user account that NAS services settings runs as determine the formatting of the data. Language preferences for a user account can be set in Windows or in Microsoft Dynamics NAV. For example, in Microsoft Dynamics NAV, in the User Personalization Card window, you can specify a language for the user. But you can also set up a default language for the Microsoft Dynamics NAV deployment by creating an empty row in the User Personalization List window. If you create an entry where you specify a language but not a user ID, then NAS services will use that language unless the session runs with a user account where you have specified another language.

The following table illustrates how combinations of language personalization and regional settings impact data that a NAS services session processes. In this example, the NAS services session runs a computer where the regional settings are set to use the Spanish format. In Microsoft Dynamics NAV, the user account that the NAS services session runs as either has a language personalization or not.

Regional settings format User personalization language ID Generic personalization language ID NAS services language and format

Spanish (Spain)


8036 and Spanish (Spain)

Spanish (Spain)

1033 and Spanish (Spain)

Spanish (Spain)


8036 and Spanish (Spain)

See Also