The CPU (central processing unit) is the chip that proccesses data. The more a system's CPU is being used, the more programs running on the system will be slowed down. The speed at which a system runs also depends on the type and version of the CPU.


The amount of data that can be sent over the network per second. InPerson tracks bandwidth in kilobits per second.

bandwidth limit

The targeted amount of information per second that InPerson can send over the network. That is, the limit set in the Call Control or Preferences panels, or the limit InPerson sets by default. When the bandwidth limit is changed, it can affect the video frame rate and quality, the audio quality, CPU usage, and the compression schemes.

home directory

A directory in which you create and store your work. Usually, the home directory is named /usr/people/<loginname>, where loginname is the name of your login account. A folder icon for your home directory appears on the desktop by default.


Integrated Services Digital Network (ISDN) lets you communicate with other systems and networks via a telephone line that uses digital, instead of analog, signals.


LAN stands for Local Area Network (for example, ethernet). There are also high speed LANs (for example, FDDI/CDDI, ATM).

login name

The name you use to identify yourself to the system. You type it to log in to the system, and the system uses it to label files that belong to you.

multicast packets

User Datagram Protocol (UDP) packets that are transmitted to groups of systems rather than individual systems. Multicast packets are different from broadcast packets in that they can be passed through routers.

InPerson uses multicast packets to send the audio and video data to multiple conference participants. This is more efficient that sending separate copies to each system.

Multicast addresses range from to InPerson uses a subset of that range—addresses between to For each conference, InPerson chooses two random addresses—one for video and one for audio.


The Internet Protocol multicast routing daemon. mrouted forwards a multicast datagram to all networks reachable by a cooperating set of mrouted routers. See the mrouted(1M) man page.

multiway conference

A conference between three or more systems.

network bandwidth

On the InPerson control panels, network bandwidth refers to the allowed bandwidth range. Next to the Network Bandwidth label, you click on the type of network you use, then InPerson sets a bandwidth range that works best with your network type.

performance preference

Your performance preference refers to whether you have selected Optimize quality or Optimize frame rate from the control panel. By default, InPerson chooses Optimize quality.


A conference between two systems.


T1 (used primarily in North America) is a 1.544 Mbps digital telephone line. E1 (especially used in Europe) is a 2.048 Mbps digital telephone line.


A link between two networks that allows multicast packets to be forwarded from one network to another. Necessary only if your routers do not support multicast forwarding.


TTL stands for time-to-live. This setting specifies the maxinum number of routers or tunnels through which multicast packets can pass.