Hi,
I was trying to download nrf5_sdk_for_mesh_v3.1.0_src.zip, which is at : https://www.nordicsemi.com/Software-and-Tools/Software/nRF5-SDK-for-Mesh/Download#infotabs,
It's tough, extremely slow and the connection always broke up.
I also tried to download nRF5_SDK_15.2.0_9412b96.zip, at http://developer.nordicsemi.com/nRF5_SDK/nRF5_SDK_v15.x.x/, much easier and fast.
So, would you please to put the mesh sdk at developer site too?