# Parameters in /vsm/

Parameters in the `/vsm` folder are used by both the master and agent service (`vsmserver.service` and `vsmagent.service`). Neither of them need to be changed on a normal ThinLinc installation. These configuration parameters reside in `/opt/thinlinc/etc/conf.d/vsm.hconf`.

/vsm/tunnel_bind_base

  The tunnels set up by the client to access various resources (audio, network resources, local printer) need one port number each on the agent server the client is connected to. This parameter decides the lowest such port that is allocated by the agent service. Each user has a port range defined by the formula:

  > `/vsm/tunnel_bind_base` + display × 10 + service_slot

  where the service_slot depends on which service will use the tunnel. This port range is however used only for sessions with display numbers less than 100. See TCP ports used by ThinLinc for an in-depth explanation of port allocation.

  Note

  This parameter should normally not be changed.

/vsm/tunnelservices

  There are several parameters under the `/vsm/tunnelservices` folder. Each one decides which ports are used as server-side termination points for the tunnels used to access client resources. See TCP ports used by ThinLinc for an in-depth explanation of port allocation.

  Note

  None of these parameters should normally be changed.

/vsm/tunnelslots_per_session

  The number of ports to reserve for tunnel port endpoints on the server. The number of ports actually used depends on the number of services defined under `/vsm/tunnelservices` . We recommend letting this parameter have its default value (10), since that provides a margin for future services. See TCP ports used by ThinLinc for an in-depth explanation of port allocation.

  Note

  This parameter should normally not be changed and must not be changed whilst there are any running sessions.

/vsm/vnc_port_base

  The port base for VNC communication. The VNC protocol runs on one port per active user on the agent host, and this is the base of the numbers used. That is, for the first user, the port will be `/vsm/vnc_port_base` + 1, for the second user `/vsm/vnc_port_base` + 2 and so on. This algorithm is used only for display numbers below 100. See TCP ports used by ThinLinc for an in-depth explanation of port allocation.

  Note

  This parameter should normally not be changed.

/vsm/vsm_agent_port

  Agent service communication. This is the port that the master connects to on an agent. This traffic is not encrypted.

  Note

  This parameter should normally not be changed

/vsm/vsm_server_port

  The port that the master service listens to.

  Note

  This parameter should normally not be changed