SAPRouter is a small application required to be installed on desktop or server. It can be used for remote SAP connectivity.
You need SAP Router for downloading SAP Notes to systems or opening a system connection to SAP.
Please follow below link which describes how to install SAProuter
http://help.sap.com/saphelp_nwpi711/helpdata/en/48/6ca4616c0707dce10000000a42189d/frameset.htm