heartbeat, switch from wifi to 4G/5G, connect use fixed address with password ...

[szcuipeng]

i need some new features:

(1) heartbeat between socket client and server (2) when my phone's network switch from wifi to 4G/5G, socket shoud reconnect and keep session https://stackoverflow.com/questions/41098670/how-to-gracefully-switch-between-networks-in-webrtc

(3) i found that Dhcp will increase address number, sometimes some nodes need connect to a server with fixed address, so a server should be use fixed address ( the server will connect to network-hub with a fixed address )

i found it: https://github.com/sinclairzx81/smoke/issues/8

(4) smoke-hub cluster