This module integrates ConnectShip with Commerce Shipping 2.x. ConnectShip is a web service that serves as an abstraction layer for every carrier's shipping rate calculation API. This means through one service call you can rate a shipment for USPS, UPS, and FedEx.
Unfortunately, there is no generally available web service that you can use to get these rates. You have to be running their Windows based server application and connecting to that to submit web service calls in XML format. As such, I don't see this module being generally useful except as an example for how to integrate carrier calculated rates into checkout using Shipping 2.x.
Installation and configuration
You must have access to a ConnectShip server with valid API credentials before you can consider using this module. This module depends on:
Once installed, you can browse to the Administration > Store > Configuration > Shipping page to edit your ConnectShip settings. In this edit form you will also enable ConnectShip package services as Commerce shipping services. After enabling or disabling services, you must clear the cache twice to ensure menu items and default Rules configurations get rebuilt.
In order for ConnectShip to determine the weight of your orders when it builds rate requests, you must attach a Physical weight field (from the Physical Fields module) to your product types and supply weight values for your products. If no weight can be determined for an order, ConnectShip will not return any shipping rates. The name of the weight field does not matter.