Available with Network Analyst license.
The ArcGIS Network Analyst extension provides broad geoprocessing functionality through the Network Analyst toolbox and the Network Analyst module.
Network Analyst toolbox
The Network Analyst toolbox contains tools for creating and editing turns, building networks, performing network analysis, and working with Network Analyst related web services. These tools are organized into an Analysis toolset, a Network Dataset toolset, a Server toolset, and a Turn Feature Class toolset.
Network Analyst module
The Network Analyst module is a Python module that provides access to all the geoprocessing tools available in the Network Analyst toolbox as well as to other helper functions and classes that allow you to automate Network Analyst through Python.