Backing Options and Backing Information for Network Serial Ports

The vSphere API uses backing objects to represent the host device that is associated with a virtual device. The API offers two types of backing objects for virtual devices: option objects and information objects.

Backing option objects identify host device support for virtual machines. An ESX host defines the set of virtual device backing options that are available for virtual machines. To use a network serial port, the ESX host must provide the virtual serial port URI backing option, which is represented by the VirtualSerialPortURIBackingOption object. For information about how to find out if the host supports the URI backing option, see Determining Backing Options.

Backing information objects supply data for virtual device configuration. Use a VirtualSerialPortURIBackingInfo object to bind a virtual serial port to a network socket. You can configure a virtual serial port to use URI backing when you create or reconfigure a virtual machine. For a description of how to configure URI backing for a network serial port, see Create a Virtual Machine with a Network Serial Port.

When you specify URI backing for the network serial port connection, you define these characteristics.

  • Direction – defines the role that the virtual machine plays in a connection with a remote system (client or server). When a virtual machine acts as a serial port client, it initiates the connection with the remote system. When a virtual machine acts as a serial port server, it listens for connections that are initiated by remote clients.
  • Service URI – identifies the target of connections. When the virtual machine acts as a client, the service URI identifies the remote system. When the virtual machine acts as a server, the service URI identifies proxy access to the host on which the virtual machine runs. See RFC3986 for information about URI syntax.
  • Proxy URI – identifies the virtual serial port proxy. The presence of the proxy URI directs the virtual machine to establish a connection with the proxy. The virtual machine always initiates the connection with the proxy.

    You can use either telnet or secure telnet (telnets) for the proxy connection. The proxy URI specification must use one of the following formats. See RFC3986 for information about URI syntax. See the description of the VirtualSerialPortURIBackingInfo data object in the vSphere API Reference for information about URI schemes and authentication parameters for network serial port configuration.

    • telnet://<host>:<port>[#key[=value][&key[=value] ...]]
    • telnets://<host>:<port>[#key[=value][&key[=value] ...]]

      When the virtual machine performs telnet negotiation with the proxy, it sends the direction and service URI information to the proxy. (See the description of the DO-PROXY command in Proxy Operation.)