The DSS provides the following call-handling capabilities or information:

• One-touch dialing of inside extensions
• One-touch Transfer
• One-touch Hold (DLC only)
• On-hook, off-hook, or Do Not Disturb status of extensions in the system
• Extension status indication (group member or room status)
• Calling Group queue status
• Message-waiting LED status
• Operator Park Zones
• Dialing of non-local extensions

The DSS, shown in the Direct Station Selector (DSS) diagram,has an array of 50 buttons, called DSS buttons , with red LEDs. A maximum of two DSSs can be connected to provide a field of 100 buttons. Ten additional fixed-feature buttons with green LEDs are at the bottom of the DSS. The first three (from left to right) on the top row are Page buttons, which are used to select the range of extension numbers represented by the DSS buttons. A fourth button (lower leftmost) is the Message Status button, which is used to turn the message status operation on and off. When you are using the Message Status feature, the LED next to each DSS button for a local extension indicates whether or not a message is waiting from a system operator. The remaining six buttons on the first DSS and the 10 buttons at the bottom of the second DSS are not operable (reserved for future use), except on a QCC, where the rightmost button on the second to last row of the first DSS activates the Direct Voice Mail feature for local extensions.

A page is a range of extension numbers assigned to a DSS. A single DSS can have three pages of extension numbers, with 50 extension numbers for each page, for a total of 150 extension numbers. When two DSSs are connected, each page's capacity is increased to 100 extension numbers. The two connected DSSs can have three pages of extension numbers for a total of 300 extension numbers.

The beginning number for each page is assigned through system programming. When an operator presses a Page button, the page of the DSS corresponds to a range of 50 (for a single DSS) or 100 (for two connected DSSs) extension numbers. The factory settings for Page buttons are as follows: the Page 1 button begins with Extension 0; the Page 2 button begins with 50; and the Page 3 button begins with 100.

If only one DSS is attached, each Page button assignment sets the console for a range of 50 extension numbers. If two DSSs are attached, each Page button assignment sets the console for a range of 100 extension numbers. If two DSSs are used, the factory setting must be changed so that the difference between extensions assigned to the range is at least 100. For example, for a three-digit dial plan, assign Page 1 button to begin with Extension 100, Page 2 button to begin with Extension 200, and Page 3 button to begin with Extension 300. For a four-digit dial plan, assign Page 1 button to begin with Extension 1000, Page 2 button to begin with Extension 1100, and Page 3 button to begin with Extension 1200.

The beginning extension number associated with each Page button is the same for all operator positions and cannot be programmed differently for individual operator positions.

Each Page button range can begin with any extension number that is a multiple of 50, in the range of 0 to 9950. To speed call handling, however, the assignments should be sequential; the range starting with the lowest extension number should be assigned to Page 1, the range starting with a higher extension number should be assigned to Page 2, and the range starting with a still higher extension number should be assigned to Page 3. You cannot program individual buttons on a DSS.