Aspera's fasp transport has no theoretical throughput limit. Other than the network capacity, the transfer speed may be limited by rate settings and resources of the computers. This topic describes how to optimize the transfer rate by setting up the global rate settings.

Global Transfer Settings

To set global fasp bandwidth, bring up the application ( asperascp ) and click Global Preferences.

Launch global preferences.

In the Global Preferences dialog select Transfers, and enter the download and upload bandwidth values in the System-Wide Settings field and click the checkboxes to enable the settings.

The preferences window.
Item Description
Limit Download/Upload Bandwidth Adjust the aggregated bandwidth cap for all download or upload fasp transfers on this computer. For more advanced bandwidth settings, refer to Bandwidth.
Default Target Rates The initial download and upload rates for all transfers.
Maximum Active Transfers Set the maximum number of concurrent upload and download transfers.

When setting the global bandwidth, the application is in fact creating Virtual Links (Vlink) and applying them to the default transfer settings. For more information about Vlinks, wee Setting Up Virtual Links.

To create global bandwidth using the command line, open the aspera.conf (/opt/aspera/etc/aspera.conf) with a text editor. The following example sets the global bandwidth with these values:

Item Value
Upload bandwidth limit (Outgoing): 88 Mbps (88000 Kbps)
Download bandwidth limit (Incoming): 99 Mbps (99000 Kbps)
<?xml version='1.0' encoding='UTF-8'?>
<CONF version="2">
  ...
  <trunks>
    <trunk>          <!-- Create a Vlink with 88000 Kbps bandwidth cap. -->
      <id>108</id>   <!-- ID: 108 -->
      <capacity><value>88000</value></capacity>
      <on>true</on>
    </trunk>
    <trunk>          <!-- Create a Vlink with 99000 Kbps bandwidth cap. -->
      <id>109</id>   <!-- ID: 109 -->
      <capacity><value>99000</value></capacity>
      <on>true</on>
    </trunk>
  </trunks>

  <default>   <!-- Global settings.-->
    <transfer>
      <out>   <!-- Use Vlink ID: 108 for global outgoing bandwidth. -->
        <bandwidth><aggregate><trunk_id>108</trunk_id></aggregate></bandwidth>
      </out>
      <in>    <!-- Use Vlink ID: 109 for global incoming bandwidth. -->
        <bandwidth><aggregate><trunk_id>109</trunk_id></aggregate></bandwidth>
      </in>
    </transfer>
  </default>
</CONF>

User Transfer Settings

The global settings for download and upload bandwidth limits cannot be reset by non-admin users. However, from the My PreferencesTransfers dialog, users can view the global limit, and they can also adjust the default target rate and maximum number of active transfers. The My Preferences dialog can be opened from Tools > Preferences or from the Preferences button in the upper-right corner of the main SCP window.