We have been looking at different approaches to do the routing Task.
First basic question is " How to calculate a route distance (Upstream or Downstream) between 2 given points"
Can we finish the above mentioned Task using Network Analyst? We wanted to make sure that Network Analyst can help us do it , so we can purchase it...
Also, do we have to build a Route Network for the above mentioned Task (assuming we don't have to worry about barriers , stops etc) and Can we use ArcGIS Server NA SOAP/REST API to get that programmatically??
Are you trying to do routing for a transportation network like a street network? I ask this because you mention upstream and downstream paths which are more typical for river, sewer, electric type networks. If you need to work with these kinds of networks then you need to construct a Geometric Network on your data and use the Utility Network Analysis toolbar. if you have a transrportation network then you need to create/build a Network Dataset and use the Network Analyst toolbar to create a route layer and solve a path on it. And you can access the same solvers on the server. Jay Sandhu