April 9, 2012

LAN Sync Overview

by with 9 comments

We’re just around the corner from releasing our much-requested LAN (Local Area Network) sync feature, which is now in the final stages of beta testing.

LAN sync enables much more efficient syncing of data between two or more computers. When SpiderOak is processing a sync between devices on the same LAN (i.e. on the same network), the devices can speak to each other locally, passing any needed data blocks directly to each other without the receiving devices having to download them from the SpiderOak servers. The originating device will still upload the changed or added files to SpiderOak to ensure the data is safely backed up and available to other computers in your SpiderOak network.

To illustrate the difference between ‘normal’ sync and LAN sync, please see the diagrams below:

Normal Sync: Device 1 uploads added or changed data to the SpiderOak servers over the Internet. Once the upload is complete and SpiderOak determines that the data is part of a sync, SpiderOak will start downloading the data to Device 2 which also occurs over the Internet. LAN Sync: Device 1 uploads added or changed data to the SpiderOak servers over the Internet (A). Once the upload is complete and SpiderOak determines that the data is part of a sync, SpiderOak again downloads the data to Device 2, only this time the download occurs directly between devices over the LAN (B). This optimization saves you time and bandwidth.

NOTE: The LAN sync feature only works for devices that are on the same LAN. For example, a sync between a home computer and a work computer will still go through the SpiderOak servers, as they do not share the same physical connection.

However, if you carry a laptop between work and home, SpiderOak is smart enough to determine the most efficient sync method, always transferring data blocks over the LAN when possible. At work, your laptop will sync with work devices over the LAN, and home devices over the internet. At home, SpiderOak will use your home LAN to efficiently transfer data from your home devices to your laptop, and data from your work devices will be downloaded over the internet.

In the end, regardless of the sync method SpiderOak uses, you can always feel safe in the knowledge that your important data is stored – securely & privately – in the cloud.

  1. How will it determine a "LAN connection"? Will it be simply based on the query "are these two devices on the same subnet"? Unfortunately, my work LAN is massive (2 /16s) so everything is subnetted into separate buildings, separate areas, separate subnets for wireless access, etc. So although I would get vastly improved speeds and could very much benefit from LAN syncing, it seems that because my desktop and my laptop would actually be on different subnets I may not be able to take advantage of it? :(

    Not sure at this point how you could begin to work around it, except maybe an actual evaluation of speed between devices (i.e. "regardless of IP addressing, can I get more than $X kb/s between these two devices"), or checking the number of hops between two devices (i.e. "the connection between these devices only has 3-4 hops, so it doesn't seem to be an Internet-based connection, we'll try a LAN sync").

  2. What id I download data manually from another device in my LAN? Will LAN sync also be used in this scenario or do I have to download the data from the server in this case?

  3. good timing! i was just looking at moving to DropBox because of not having this feature. will wait for this and upgrade account if it works!

  4. Was seriously considering another product until now! This is great news, can't wait to use it.

  5. Any better indication of when this is due? My business is a major SugarSync user and I am fed up with their inability to impliment their user's function requests/requirements. Lan Sync on Spider Oak will make us switch.

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