diff --git a/docs/README.erb.md b/docs/README.erb.md
index be3ff637..90d5d7b9 100644
--- a/docs/README.erb.md
+++ b/docs/README.erb.md
@@ -232,19 +232,27 @@ To check manually:
 
 ## <a name="fasp_prot"></a>FASP Protocol
 
-Most file transfers will be done using the FASP protocol. Only two additional files are required to perform
-an Aspera Transfer:
+Most file transfers will be done using the FASP protocol, using `ascp`.
+Only two additional files are required to perform an Aspera Transfer, which are part of Aspera SDK:
 
 * ascp
 * aspera-license (in same folder, or ../etc)
 
-This can be installed directly with
+This can be installed either be installing an Aspera transfer sofware, or using an embedded command:
 
 ```
 $ <%=cmd%> conf ascp install
 ```
 
-Those can be found in one of IBM Aspera transfer server or client with its license file (some are free):
+If a local SDK installation is prefered instead of fetching from internet: one can specify the location of the SDK file:
+
+```
+$ <%=cmd%> conf ascp install --sdk-url=file:///SDK.zip
+```
+
+The format is: `file:///<path>`, where `<path>` can be either a relative path (not starting with `/`), or an absolute path.
+
+If the embedded method is not used, the following packages are also suitable:
 
 * IBM Aspera Connect Client (Free)
 * IBM Aspera Desktop Client (Free)
@@ -2729,6 +2737,7 @@ So, it evolved into <%=tool%>:
 
 	* renamed command `nagios_check` to `health`
 	* agent `http_gw` now supports upload
+	* added option `sdk_url`
 
 * 4.0.0
 
diff --git a/lib/aspera/cli/plugins/config.rb b/lib/aspera/cli/plugins/config.rb
index da2813de..935eb6b2 100644
--- a/lib/aspera/cli/plugins/config.rb
+++ b/lib/aspera/cli/plugins/config.rb
@@ -107,11 +107,13 @@ def initialize(env,tool_name,help_url,version)
           self.options.add_opt_simple(:default,"set as default configuration for specified plugin")
           self.options.add_opt_simple(:secret,"access key secret for node")
           self.options.add_opt_simple(:secrets,"access key secret for node")
+          self.options.add_opt_simple(:sdk_url,"URL to get SDK")
           self.options.add_opt_boolean(:test_mode,"skip user validation in wizard mode")
           self.options.add_opt_simple(:version_check_days,Integer,"period to check neew version in days (zero to disable)")
           self.options.set_option(:use_generic_client,true)
           self.options.set_option(:test_mode,false)
           self.options.set_option(:version_check_days,7)
+          self.options.set_option(:sdk_url,'https://eudemo.asperademo.com/aspera/faspex/sdk.zip')
           self.options.parse_options!
           raise CliBadArgument,"secrets shall be Hash" unless @option_secrets.is_a?(Hash)
         end
@@ -524,7 +526,7 @@ def execute_action_ascp
               return {:type=>:status, :data=>"saved to default global preset #{preset_name}"}
             end
           when :install
-            v=Fasp::Installation.instance.install_sdk
+            v=Fasp::Installation.instance.install_sdk(self.options.get_option(:sdk_url,:mandatory))
             return {:type=>:status, :data=>"Installed version #{v}"}
           end
           raise "unexpected case: #{command}"
diff --git a/lib/aspera/fasp/installation.rb b/lib/aspera/fasp/installation.rb
index d88ad10a..aa75a01e 100644
--- a/lib/aspera/fasp/installation.rb
+++ b/lib/aspera/fasp/installation.rb
@@ -176,10 +176,16 @@ def bypass_keys
         return [:ssh_bypass_key_dsa,:ssh_bypass_key_rsa].map{|i|Installation.instance.path(i)}
       end
 
-      def install_sdk
+      def install_sdk(sdk_url)
         require 'zip'
         sdk_zip_path=File.join(Dir.tmpdir,'sdk.zip')
-        Aspera::Rest.new(base_url: SDK_URL).call(operation: 'GET',save_to_file: sdk_zip_path)
+        if sdk_url.start_with?('file:')
+          # require specific file scheme: the path part is "relative", or absolute if there are 4 slash
+          raise 'use format: file:///<path>' unless sdk_url.start_with?('file:///')
+          sdk_zip_path=sdk_url.gsub(%r{^file:///},'')
+        else
+          Aspera::Rest.new(base_url: sdk_url).call(operation: 'GET',save_to_file: sdk_zip_path)
+        end
         filter="/#{Environment.architecture}/"
         ascp_path=nil
         # first ensure license file is here so that ascp invokation for version works
@@ -220,9 +226,8 @@ def install_sdk
       PRODUCT_INFO='product-info.mf'
       # policy for product selection
       FIRST_FOUND='FIRST'
-      SDK_URL='https://eudemo.asperademo.com/aspera/faspex/sdk.zip'
 
-      private_constant :BIN_SUBFOLDER,:ETC_SUBFOLDER,:VARRUN_SUBFOLDER,:PRODUCT_INFO,:SDK_URL
+      private_constant :BIN_SUBFOLDER,:ETC_SUBFOLDER,:VARRUN_SUBFOLDER,:PRODUCT_INFO
 
       # get some specific folder from specific applications: Connect or CLI
       def get_product_folders(name)