HOWTO: How to optimize file-based and VSS-BBT transfers for WAN connections

  • 7970567
  • 16-Jul-2009
  • 27-Apr-2012


PlateSpin Migrate
PlateSpin Protect
PlateSpin Forge
PlateSpin Portability Suite and PowerConvert v7.0 and higher


This article outlines how to optimize the file-based transfer engine for conversions with source and target servers across a Wide Area Network connection. These settings are global and will affect all jobs. File-based jobs include Live File-Based, VSS, and Take Control. Some settings also apply to VSS-BBT jobs, see the chart in the resolution section for more details.


Data transfer optimization settings are contained in the productinternal.config file located in the \Web\ directory of the PlateSpin installation folder.

\Program Files\PlateSpin Portability Suite Server\Web\productinternal.config

Please note, these settings are Global to the PlateSpin server. Local gigabit LAN conversion speeds may be negatively affected if these values are modified.

Below is a list of the configuration parameters with two sets of values: the defaults and the values recommended for optimum operation in a high-latency WAN environment.


Default Value

For High-Latency WANs



Controls the number of TCP connections opened for file-based data transfer. (Modifying this value can have an adverse affect on CPU utilization of the source server)


2 4 to 6



Specifies the packet-level compression threshold in bytes. (Not compatible with VSS-BBT transfers)


0 (disabled) max 65536 (64 KB)



Controls the number of threads used for packet-level data compression. Ignored if compression is disabled. (Not compatible with VSS-BBT transfers)

Because the compression is CPU-bound, this setting might have a performance impact during Live Transfer.


2 N/A



TCP/IP window size setting for file transfer connections; controls the number of bytes sent without TCP acknowledgement, in bytes.

When the value is set to 0, the default TCP window size is being used (8 KB). For custom sizes, specify the size in bytes. Use the following formula to determine the proper value:


For example, for a 100 Mbps link with 10 ms latency, the proper buffer size would be:

(100/8)*0.01 * 1024 * 1024 = 131072 bytes


0 (8192 bytes) max 5242880 (5 MB)