From our Project Manager Vladimir Jirasek

1. you will run service discovery platform. What about dependency between SDP and rest of the network? What if SDP is unavailable for some reason?

Without SDP there is no way to discover server nodes. We will design and operate SDP to reflect its importance.

2. what is the purpose of HAproxy on client side?

It is used for the Proxy service and establishes TLS tunnel to the server side HAProxy. Client side HAProxy then listens on localhost for a browser to use it as a proxy. The tunnel then transports proxy request/response traffic to the server side forward proxy. Think of it as an encrypted netcat for the proxy traffic. As we will control both client and the server side of the encrypted tunnel, we will protect against typical TLS attacks, such as man in the middle attack, TLS cipher downgrade.

3. what about QoS on VPN server side? As I know OpenVPN does not have built-in QoS features, do you plan to use third-party component for this?

OpenVPN does have option -passtos which allows for the VPN packages to inherit ToS bits of the inside packets. We will keep this option enabled. Additionally, we do plan to use OS to limit bandwidth where necessary. On Linux this can be easily achieved by using tc command: https://github.com/firehol/netdata/wiki/You-should-install-QoS-on-all-your-servers

4. any plans to implement lite version of client software without local copy of blockchain?

Not firm plans but yes we are looking to develop wallet-vpn client software that would use trusted remote Blockchain daemons.

Hope this answer your questions