A virtual port is a software emulation of a port which normally would be present in hardware. This is most commonly used with modems and printers.
Many internal modems emulate a COM port. When modems first became common by far the most common type was an external modem which plugged into a serial port (a COM port) in the back of the machine. Nearly all of the early dial-up networking applications were written with the assumption that the modem could be found on one of these COM ports. While it is no longer necessary for the modem to reside on a COM port, most new modems still emulate one in order to maintain compatibility with these legacy applications. Printers can also reside on a virtual port for much the same reasons. All printers used to plug into a parallel port (an LPT port) on the computer. As a result many legacy programs were written with the assumption that any printers would be located on an LPT port. When USB printers became commonplace it became necessary to allow these USB printers to be assigned a virtual parallel port in order to maintain compatibility with these older programs. This can be configured in the OS in the printers settings and is most often used for DOS-level point-of-sale or data-entry applications.
A physical port, as opposed to a virtual or logical port is an interface on a computer into which you can insert a connector for a device.
A USB virtual COM port is a software interface that enables applications to access a USB device as if it were a built-in serial port. Many USB virtual COM-port devices function as bridges that convert between USB and RS-232 or other asynchronous serial interfaces.
A Port VLAN ID (pvid) is a default VLAN ID that is assigned to an access port to designate the virtual LAN segment to which this port is connected. The pvid places the port into the set of ports that are connected under the designated VLAN ID. Also, if a trunk port has not been configured with any VLAN memberships, the virtual switch's Port VLAN ID (pvid) becomes the default VLAN ID for the ports connection.
COM1 and COM2 originally referred to the serial port interfaces on a PC. Now they can refer to any port, virtual or physical.
in Configuration menu -> Virtual Serveradd your ports and Ip address .
A port is a generic term for a way in or out of a computer. A means of tranferring data into and out of the computer. A physical port is a socket on the computer, where you can connect a data cable. A virtual port is a program area, set aside and arranged so that the data can be handled by the processor, as it arrives or leaves the computer.
A computer port, is an area reserved for input and output data. Sometimes physically linked to a socket on the computer but also a virtual area, ready to be sent via the internet. A port call, is an instruction in the program code, that addresses a port and reads back the data found there.
"Free port" could describe an unused computer peripheral interface socket or virtual connector such as: I really wanted to plug in my printer but I didn't have a free (USB) port. It could also describe a tax and tariff -exempt entry into a country. Freeport, Bahamas is a free port.
Virtual Ports Virtual Ports are used in TCP and UDP to identify unique end-to-end connections. They are called 'virtual ports' because a single physical connector can serve multiple connections. Each side of a connection uses its own port number, which does not change during the life of that connection.Client-Server PairingsAll TCP and UDP traffic utilizes a client-server scheme, so there is always a client port and a server port used for every connection. A pair of fields within the TCP and UDP headers is used to track the source and destination Virtual Port Numbers used for that socket connection. Each field in the header is sixteen bits wide, so the value in the field can range from 0 - 65534. Each computer host uses a unique IP address, and also uses a unique source and destination port pairings to identify that specific connection between the two computers. Typically, when your computer connects to a website, it connects to the destination website on port 80 (the default port for HTTP / web traffic). A different source port on the local host is used. At one time, this port number was the next number above 1024 that wasn't already in use for another connection. For example, the first website connection would be set up on the source port of 1025 and the second connection on 1026. If the 1025 port is no longer needed and is closed, and another port is needed, then 1025 would be used.Today, to defeat hackers, computer systems are choosing the source port at random as hackers can predict this behavior and hijack sessions by predicting new connections being opened.Servers run network services, these services are bound to a virtual port and listen for communication on that virtual port. It is possible for multiple clients to connect to the same service and thus, use the same destination port number when connecting to the server. Because each client uses a unique IP address and port number, the server can keep track of up to 65534 connections per host.However, whether the port number is the source, or the destination port depends on which side is currently transmitting information. The client and server asynchronously transmit and receiving information using these ports.
Port 3389 is the only port you need to open. Windows will attempt to stream sound through User Datagram Protocol (UDP) first. If no port is available for UDP, sound will stream through a virtual channel in Remote Desktop Protocol, which uses port 3389. http://www.microsoft.com/windowsxp/using/mobility/rdfaq.mspx