[partial file transfers similar to bittorrent client]

Hello,

I have following situation here:

1. One bittorrent sync client named a connected to the internet.

2. Two other clients named b and c connected together to the internet via router.

B and c has a local lan connection also.

3. Client a has a big file to sync to the others.

4. Client b syncing with a with high rate.

5. Client c syncing with a with slow rate.

Now my question (im using 1.0.134 windows version of btsync):

Why do not client b synchronize parts of the big file it already have with c as a bittorrent client do?

The sync via lan only takes place, if one client (b or c) has the whole file synchronized.

Thanks.

Greetings.

Marcus