What makes it?

[starkovv]

What kind of components is OpenMPTCPRouter?

1. As far as I understand the minimum requirements are:
   – client node with 2 uplinks, no public IP required
   – VDS with 1 uplink and public IP

2. Both should support MPTCP in kernel.

3. What version of MPTCP should it support: v0 or v1?
   As far as I know MPTCP package from https://multipath-tcp.org is v0. While the version from https://www.kernel.org is v1. Both are not compatible with each other.

4. What application makes the MPTCP pipe from the client to the server? Is it Shadowsocks?

I'm playing around with MPTCP in my lab.
Here is the client:

# uname -a
Linux nanopi-r4s 5.11.12-rockchip64 #trunk SMP PREEMPT Thu Apr 8 19:16:55 UTC 2021 aarch64 aarch64 aarch64 GNU/Linux

# dmesg | grep MPTCP
[    1.323437] MPTCP token hash table entries: 4096 (order: 4, 98304 bytes, linear)

# sysctl -a | grep mptcp
net.ipv4.tcp_available_ulp = mptcp
net.mptcp.add_addr_timeout = 120
net.mptcp.enabled = 1

And here is the server:

# uname -a
Linux demo-gw1 5.11.12-051112-generic #202104071432 SMP Wed Apr 7 14:50:17 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

#  dmesg | grep MPTCP
[    0.498016] MPTCP token hash table entries: 1024 (order: 2, 24576 bytes, linear)

# sysctl -a | grep mptcp
net.ipv4.tcp_available_ulp = espintcp mptcp
net.mptcp.add_addr_timeout = 120
net.mptcp.enabled = 1

[Ysurac]

For now I don't "play" with upstreamed MPTCP and there is lot of commit in MPTCP-next ( https://github.com/multipath-tcp/mptcp_net-next ) not yet upstreamed.

For OpenMPTCProuter, clients connexions must be able to join VPS public IP and VPS and router use patched MPTCP kernel.
MPTCP v0 is used from https://github.com/multipath-tcp/mptcp/tree/mptcp_trunk with some patches and updated to kernel 5.4.10*.
Between router and VPS a proxy is used for TCP (Shadowsocks or V2ray that transport UDP over TCP so work for UDP too), and a VPN for traffic that is not TCP (ICMP, UDP,...).