Skip to main content



How can we help you?


Druva Documentation

How to cap the LAN and WAN bandwidth for On-Premise backups

Heads up!

We've transitioned to a new documentation portal to serve you better. Access the latest content by clicking here.

  This article applies to:

  • OS: Windows and Linux
  • Product edition: inSync On-Premise


This article describes how you can configure inSync On-Premise Server to respond to backup and restore requests in situations where fluctuating connectivity is expected. 

Back up over LAN and WAN

If you set the bandwidth for your inSync setup as a percentage value of the available bandwidth, you can ensure that your inSync setup works at all bandwidths within the defined bandwidth limits.

To set the bandwidth, you must modify the WANBW_LOWCAP and LANBW_LOWCAP parameters in the inSyncServer. cfg (file).

The “LOWCAP” settings work only if bandwidth throttling is defined as a percentage value of available bandwidth.

The WANBW_LOWCAP and LANBW_LOWCAP parameters indicate the amount of bandwidth (in bytes) that can be consumed by backups when the connectivity is low (typically, 64 Kbps for LAN and 16 Kbps for WAN). The default value of WANBW_LOWCAP is 16 KB while the default value of LANBW_LOWCAP is 64 KB.

Example: The Druva inSync Administrator has set the Maximum WAN Bandwidth to 20% and the available bandwidth at the users end is 200 Kbps. In this scenario, Druva inSync Client sends the data to the server using only 20%, that is 40 Kbps.

However, if the available network bandwidth is 34 Kbps and if the Minimum Bandwidth of WAN backup is 16 Kbps, the backups will not happen at 6.8 Kbps (20% of 34kbps). Instead, the backups will happen at 16 Kbps which is the default value set in WANBW_LOWCAP.

In the above scenario, if the WANBW_LOWCAP is set at 8 Kbps, the backups will happen at 8 Kbps.


To set the WANBW_LOWCAP and LANBW_LOWCAP parameters:

  1. Stop the inSync Server services.
  2. Locate the inSyncServer.cfg file.
    • Windows: C:\ProgramData\Druva\inSyncCloud\inSyncServer4\inSyncServer.cfg
    • Linux: /etc/inSyncCloud/inSyncServer/inSyncServer.cfg
  3. Open the inSyncServer.cfg in a text editor.
  4. Locate the WANBW_LOWCAP and LANBW_LOWCAP parameters.
  5. Set these parameters to a value (expressed in bytes) that indicates the bandwidth that will be consumed when connectivity is low.
  6. Save your changes.