Available with Network Analyst license.
There are resources within the ArcGIS documentation to help you work with Network Analyst functionality in a server environment. Below is a list of links to relevant topics.
- Get a general overview of network analysis services on ArcGIS Server
- Work through a tutorial on publishing a network analysis service
- See examples of publishing geoprocessing services that use the ArcGIS Network Analyst extension
The documentation in the Prepare window warning messages section of the Network Analyst help describes solutions to errors and warnings that may appear when publishing Network Analyst functionality to ArcGIS Server.