more topics Pools Feature

Description

Hybrid/PBX mode allows outside lines/trunks to be grouped together in pools. Users select lines/trunks by using SA buttons, instead of having separate buttons for each line/trunk in the system. To access pools using SA buttons, people dial pool dial-out codes. Pools also can be assigned to buttons on one or more telephones to allow a user to select the pool without dialing the pool dial-out code or ARS access code. The factory setting does not allow any extensions to use pool dial-out codes. To allow a user to access a pool by entering a dial-out code, the System Manager must remove the restriction for the dial-out code and the extension.

When the system is set up and the Hybrid/PBX mode of operation is selected, the system automatically groups lines/trunks into the following pools:

• All loop-start lines (basic and special-purpose) are assigned to the main pool. The factory-set extension number for the main pool is 70.
  
  
• All trunks programmed as ground-start are assigned to the pool with the factory-set extension number 890.
  
  

Ground-start trunks are assigned to the ground-start pool on initialization, except in a system modified for permanent Key mode operation.



• All dial-in tie trunks are assigned to the pool with the factory-set extension number 891.
  
  
• All automatic-in tie trunks are assigned to the pool with the factory-set extension number 892.
  
  

The factory setting for the type of line/trunk connected to an 800 GS/LS-ID, 408 GS/LS-ID-MLX, or 412 LS-ID-TDL module is loop-start. The system does not automatically make pool assignments for loop-start, ground-start, or tie trunks that are emulated by using a T1 facility. Each of these types must be grouped into a pool through system programming.

The system can have a maximum of 11 pools. Each pool can be assigned to a button on a maximum of 64 extensions. The number of lines/trunks in each pool is limited only by the number of lines/trunks connected to the system. A line/trunk, however, can be assigned to only one pool.

Consider the following points when planning pools:

• All private networked trunks must be assigned to pools; a different pool should be used for each type of trunk (T1-emulated tie trunks, PRI trunks, and analog tie trunks).
  
  
• Users must not be given dial access or Pool button access to pooled private network trunks. To use these pools, users dial non-local dial plan extensions just as they would local extensions. They also use these pools when they dial ARS for outside calls, and the ARS tables route the calls to other networked switches (see Automatic Route Selection and Tandem Switching for details).
  
  
• To allow local users to dial extensions on a remote networked system, UDP routing is used. Pools containing tandem PRI trunks should be assigned to Route 1. For details, see Uniform Dial Plan Features.
  
  
• If a directly networked system has no trunks connected to the public switched telephone network, the pool and ARS assignments listed below are required in order to make equal access (10xxx, 101xxxx, also called Interexchange or IXC) calls.
  
  
• The local system must have its networked trunks assigned to the main pool.
  
  
• The local ARS access code is automatically prepended to the dialed number.
  
  
• The local ARS access code must match that of a remote system that is networked to the local system.
  
  

CAUTION:

Because of the above requirement, it is a good idea for all systems in a private network to use the same ARS access code. If a networked system without PSTN trunks is in the same location as another networked system over which Special Numbers calls can go out to the PSTN and reach correct services, then the arrangement described above is practical. In most cases, however, each system in a network should have at least one loop-start line, which is assigned to the main pool and available in the event of a power failure. This allows Special Number calls (911 calls, for example) to reach the correct local services. It also means that IXC calls are routed to the main pool analog line or lines. If many IXC calls are made, then the number of lines assigned to the main pool must be increased.



• If a networked system has no trunks connected to the public switched telephone network, the following pool and ARS assignments are required in order to make Dial 0 or N11 calls:
  
  
• The local system must have its networked trunks assigned to the main pool.
  
  
• The local ARS programming must prepend the ARS access code of the remote switch that is directly connected to the local private network trunks.
  
  
• If remote users are going to use networked lines connected to your local system, the Remote Access feature is used to set them up. See Remote Access and Tandem Switching.

Topics
	Description
	At a Glance
	Considerations & Constraints
	System Programming
	Mode Differences
	Telephone Differences
	Feature Interactions