Configuring GroupVPN

GroupVPN has two modes on establishing the P2P connection. One create P2P connection once it starts to run, the other starts to establish connection when there appears a packet that is destined to a node without P2P connection yet. We call former as persistent mode and latter as on-demand mode.

Persistent Connection Mode

Persistent connection establishes connection to all remote nodes right after it starts to run. The established connections are persistent given that the GroupVPN is running. It is the default mdoe of operation, but has a drawback of connection overhead when the node number increases. Note that when new node appears on GroupVPN, it establishes connections to all nodes in the GroupVPN network.

On-demand Connection Mode

On-demand connection mode establishes P2P connection only when there is a demand on connection. Technically, when a packet that is destined to a node without P2P connection yet is captured in a tap device, it starts to establish P2P connection. This mode of connection is useful for reducing connection overhead. It also disconnects P2P connection after given threshold of period without traffic. On-demand connection is configurable through config file. Below two fields are relevant to on-demand connection mode.

• "on-demand_connection": true

• "on-demand_inactive_timeout": 600

Set the "on-demand_connection" field to true allows on-demand connection. Omitting or setting false this field makes the GroupVPN run on default(persistent) mode. "On-demand_inactive_timeout" sets the threshold period of disconnecting P2P.