Ring Groups

Description

When Ring Groups are programmed, calls ring multiple telephones, stopping when any one of them picks up. The following ring modes are available for programming:

Ring All - rings all members of the group in unison. Second caller is in a queue until the first call is answered.

Terminal Ring - searching always from the top of the member list, each call rings the first available member of the group. If not answered before the Call Ringing Timer expires, the call is redirected away from the group. If the search finds no available member, the call is placed in a queue; then, after the Call Queued Timer expires, it is sent to an overflow or rerouting destination.

Terminal Cascade Ring - starting the hunt from the top of the member list, each new call rings the first available member for the duration of the Cascade Ring Timer. When the timer expires, the hunt continues down the list for the next available member, and so on. When the initial starting position (top of the list) is reached, hunting proceeds until either a member answers the call or the Call Ringing Timer expires and the call is redirected to an overflow or alternate destination. If the initial hunt finds no available member, the call queues; then, after the Call Queued Timer expires, it is sent to an overflow or rerouting destination.

Circular Ring - searching begins at the member after the last one to receive a call and stops to ring the first available member. If not answered before the Call Ringing Timer expires, the call is redirected away from the group. If the hunt finds no available member, the call is placed in a queue; then, after the Call Queued Timer expires, it is sent to an overflow or rerouting destination.

Circular Cascade Ring - using the circular search method rings the first available group member after the last one to receive a call. Ringing lasts for the duration of the Cascade Ring Timer. When the timer expires, the search continues down the list for the next available member, and so on. When the hunt starting position is reached, the search continues until either a member answers the call or the Call Ringing Timer expires and the call is redirected to an overflow or alternate destination. If the initial search finds no available member, the call queues; then, after the Call Queued Timer expires, it is sent to an overflow or rerouting destination.

Member availability which determines whether calls queue to the ring group or overflow to an alternate answer point is defined as follows:

Available

Unavailable

If a single member is in one of these states, calls will queue:

If all the members are in the any of the following states, calls immediately overflow:

  • Do Not Disturb

  • Out of Service (immediate overflow applies only if all members are local non-resilient; see Note for details)

  • Absent

Other features of Ring Groups:

NOTE: The display is restricted for other telephone models.

NOTES

 

NOTE: When all members are Out Of Service, the immediate overflow is applied only if all members are local non-resilient. If there are any RDN or resilient members in that group, callers will be placed in the ringing queue, then the waiting queue, and the overflow will not take place until the timer expires.

NOTES

 

IMPORTANT: It is strongly recommended to use DPNSS trunks (IP, XNET, Digital DPNSS) to access Ring Group remote members. If non-DPNSS trunks are used, features that rely on DPNSS, such as override forwarding, will not function.

Conditions and Feature Interactions

NOTE: The system can ring a maximum of 80 broadcast group's in unison. The maximum number of appearances in all 80 groups that it can ring is 172. Of the 172, up to 80 single-line appearances can be rung with the remaining appearances being multiline sets. Devices in excess of these limits will not ring. Error logs may also be generated during the call.

NOTE: The system does not check for invalid destinations.

NOTE: When a call to a ring group is terminated by the group's member, the member's - not the group's - call coverage number is used to identify the post call destination.

NOTE: When all members are Out Of Service, the immediate overflow is applied only if all members are local non-resilient. If there are any RDN or resilient members in that group, callers will be placed in the ringing queue, then the waiting queue, and the overflow will not take place until the timer expires.

NOTE: The following privacy features are not supported when a call is forwarded to a remote group member: Telephone Directory "Privacy" option, COS option "Name Suppression on outgoing trunk calls", and COS option "Suppress Delivery of Caller ID Display between Sets". The forwarding party number and, for the 5140 and 5240 sets, the name are displayed on the remote member's set, even if these options are enabled on the forwarding party. This behavior does not apply to calls forwarded to local members of a ring group.

NOTE: Missed call logs will not be generated if an RDN is programmed as the prime member of a ring group. It is recommended that you do not program an RDN as the prime member if the Call History is required for the ring group.

Ring Group Timer Interactions

Depending on the scenario, the following timers may be applied to unanswered ring group calls.

Form

Timer

Description

Notes

Ring Groups

Call Ringing

The length of time a call rings a ring group member before being redirected away from the ring group.

  • Strongly recommended to be smaller than either system "Call Rerouting Timer" or COS option "Answer Plus System Reroute Timer".

  • In the worst case scenario, a call rings for the duration of both timers before being redirected to an overflow or rerouting destination. See the Examples below for details.

Call Queued

The length of time a caller is waiting in a queue before being redirected to an overflow (if configured) or 1st-alternative rerouting destination.

System Options

Call Rerouting

The length of time a call rings a station before being rerouted to the station's 2nd alternative number.

  • Strongly recommended to be greater than any ring group timer (Call Ringing and Call Queued) and the CFNA timer.

Class of Service (COS) Options

Call Forward - No Answer (CFNA) of the Overflow station

The length of time a call rings a station before being rerouted to the 1st-alternative rerouting destination. This timer is reset each time a call is forwarded.

  • Strongly recommended to be smaller than either Call Rerouting (System Options) or COS Answer Plus System Reroute timer.

Answer Plus System Reroute of a Ring Group

The length of time a call rings a station before being rerouted from the 1st to the 2nd-alternative rerouting destination.

  • Strongly recommended to be greater than any ring group timer (Call Ringing or Call Queued) and the CFNA timer.

  • If configured, it overrides the system Call Rerouting Timer.

Ringing Timer of the caller

The length of time a station rings another station.

  • Will determine the length of time an internal call rings the last configured overflow or rerouting destination. The default values is 180 s.

  • This timer is reset each time a call is redirected to the next alternative destination.

NOTE: For external calls, the last destination will ring until the caller ends the call.

Example Scenario 1: Overflow, 1st, and 2nd Call Rerouting Alternative destinations are configured

In this scenario, it is recommended that the system Call Rerouting Timer for the ring group be configured based on the following formula:

Ringing Timer + Queued Timer + CFNA Timer + some additional time for the 1st Alternative destination to answer the call before rerouting to the 2nd Alternative.

In this example: 30 s + 30 s + 17 s +13 s = 90 s

Call Processing Algorithm

90 - 30 - 17 = 43s.

For internal calls, the 2nd Alternative rings until the COS option Ringing Timer for the caller expires (default 180 s).

For external calls, the 2nd Alternative rings until the caller clears the call.

The following diagram illustrates the above scenario.

Ring Group Member Rings

Overflow Destination Rings

1st Alternative Destination Rings

2nd Alternative Destination Rings

0 s                    30 s

17 s

 

 

|----------------------------------------->

------------------------------------>

 

 

(Ring Group Call Ringing Timer)

(CFNA Timer)

43 s

180 s (internal call)

 

 

(90 - 30 - 17))

(COS option Ringing Timer)

|-------------------------------------------------------------------------------------------------------------------------------->

-------------------------------------------->

(System Call Rerouting Timer: 90 s)

 

Worst Case Scenario

90 - 30 - 30 - 17 = 13 s.

For internal calls, the 2nd Alternative rings until the caller's COS option Ringing Timer expires (default 180 s).

For external calls, the 2nd Alternative rings until the caller clears the call.

In this scenario, an internal call rings for the total of 270 seconds: 30 + 30 + 17 + 13 + 180. An external call rings until the caller ends the call.

Example Scenario 2: No Overflow, only 1st and 2nd Call Rerouting Alternative destinations are configured

In this scenario, it is recommended that the system Call Rerouting Timer for the ring group be configured based on the following formula:

Ringing Timer + Queued Timer + some additional time for the 1st Alternative Destination to answer the call before rerouting to the 2nd Alternative.

In this example: 30 s + 30 s +15 s = 75 s

Call Processing Algorithm

For internal calls, the 2nd Alternative rings until the caller's COS option Ringing Timer expires (default 180 s).

For external calls, the 2nd Alternative rings until the caller clears the call.

The following diagram illustrates the above scenario.

Ring Group Member Rings

1st Alternative Destination Rings

2nd Alternative Destination Rings

0 s                     30 s

 

 

|----------------------------------------->

 

 

(Ring Group Call Ringing Timer)

45 s

180 s (internal call)

 

(75 - 30)

(COS option Ringing Timer)

|------------------------------------------------------------------------------------------>

-------------------------------------------->

(System Call Rerouting Timer: 75 s)

 

Worst Case Scenario

For internal calls, the 2nd Alternative rings until the caller's COS option Ringing Timer expires (default 180 s).

For external calls, the 2nd Alternative rings until the caller clears the call.

In this scenario, an internal call rings for the total of 255 seconds: 30 + 30 + 15 + 180. An external call rings until the caller ends the call.

Programming

  1. Ring Groups form

NOTES

 

  1. Call Coverage Services form

  1. (Optional) Call Rerouting form

  1. Class of Service Options form

Device Support

Ring Groups functioning as answering points for ER Adviser emergency calls cannot have the following DNs as members:

NOTE: The system does not prevent you from programming the above numbers as remote members of a ring group. However, those invalid members will be blocked and marked absent at call processing time (a log will be generated).

Operation

None