A Hunt Group (HG), sometimes also referred to as Multiline Hunt Group (MLHG), permits the distribution of incoming calls to associated subscribers (members). If a member is busy or does not accept an incoming call, the call is automatically routed to another member of the hunt group.
The HG can be reached at a single DN, the so-called Pilot Number of the HG. A Hunt Group is uniquely identified by its Pilot Number, which cannot be changed after the Hunt Group has been created.
If the Pilot Number is related to a station (i.e. it is assigned to a SIP phone subscriber), the HG is also referred to as Master Hunt Group. The respective station is called Master Station and provides access to certain features that control the hunt group.
If the Pilot Number is not related to a station (i.e. it is assigned to a profile-only subscriber) and is used only as an access number, the HG is also referred to as Pilot Hunt Group.
Since Release 4.0R1 it is also possible to assign a modifiable, descriptive name to each hunt group, which facilitates its identification in filters, lists, etc.
The hunting sequence may be as follows:
Circular Hunting with Memory
An incoming call causes Lotus Sametime Unified Telephony to progressively search for an idle station within the hunt group, starting with station position stored when the previous call to the hunt group was made. When a line is selected to complete a call to the group, the line that is one past it in the group is marked to become the starting point for the hunt on the next call to the hunt group. For example, if the last line in the group was chosen for the previous call, this is the first line in the group for the next call.
An incoming call causes Lotus Sametime Unified Telephony to progressively search for an idle station within that hunt group. The hunting sequence starts with the first member and ends with the last member in the group. The first available member is chosen to present the call to.
Since Release 5 there are two "modes" w.r.t overflow handling:
Linear Conditional, where calls are routed to the overflow destination only if the hunting passes the last group member and there either is no queue, the queue is full or the call has been queued for too long.
This is the traditional Linear Hunting mode.
Linear Unconditional, where calls are immediately routed to the overflow destination, if the hunting passes the last group member.
This behaviour is preferable if the overflow destination is again a Hunt Group, e.g. on another switch (network-wide Hunt Group).
If no overflow destination has been provisioned, then the Conditional mode will be used.
Uniform Call Distribution (UCD)
Lotus Sametime Unified Telephony routes an incoming call to the station within the hunt group that has been idle the longest.
Lotus Sametime Unified Telephony does not perform the distribution of calls to agents, and all incoming calls are queued. For the distribution to work:
The hunt group must be provisioned as a pilot hunt group.
The Pilot Number must be marked for CSTA and must be monitored by a CSTA application, which allows an external application to be notified of calls going into the queue, and to subsequently retrieve (reroute) those calls.
For example, the Concierge application, which is now part of the Lotus Sametime Unified Telephony solution, uses Hunt Groups provisioned for Manual Hunting to allow attendants to pick up waiting, unanswered or parked calls.
A hunt group is busy when one of the following conditions are present:
There are no idle members in the group to present the call to, and there are no idle positions in the queue.
It is in night service.
Upon determining busy, the sequence of treatment is as follows:
- If the group is in night service, the call is routed to the night service DN.
- Otherwise, if there is an associated queue with idle positions in the queue, queuing will be performed.
- Otherwise, if Call Forwarding - Busy Line is active on the group via the pilot DN, the call is forwarded.
- Otherwise, if an Overflow DN is present, the call is routed to it.
- Otherwise, busy tone is given. This is the default.
The blocking status of the hunt group and its members is determined as follows:
If the pilot DN of the hunt group is dialed, only the blocking state of the pilot DN is checked. If the pilot DN is blocked, hunting does not occur - no matter what the blocking state of the group members is. If it is not blocked, normal hunting occurs.
If a member's DN is dialed directly, the blocking state of the member's DN is checked.
All members of a hunt group must reside in the same Business Group.
Calls delivered to members of pilot hunt groups cannot overflow or forward to a remotely located voice mail system.
Calls originated by a hunt group member can route over a network interface.
Calls arriving over a network interface can route to a hunt group interface.
If the pilot line is associated to a PBX, all hunt group members must reside in this very PBX.
Lotus Sametime Unified Telephony supports up to 25,000 hunt groups. Each hunt group can contain up to 2,048 stations. A station (DN) can be a member of up to 32 hunt groups. Although each station has its own DN, the system administrator can designate it as non-external.
Parent topic: Mobility and Collaboration
Each Hunt Group can optionally have an associated overflow queue to which calls are routed if there are no idle members in the group to present the call to. Queued calls are distributed to the next available line in the Hunt Group as it becomes available (on a first-in, first-out basis).
The Overflow feature permits an overflow DN to be assigned to a Hunt Group. This DN is used as destination DN to which unanswered incoming calls are sent when the queue is full.
The Make Busy feature permits a station to appear busy to incoming calls that hunt to the line. Calls to a line's non-hunt DN are still permitted, as are call originations.
The stop hunt feature provides the ability to terminate all hunting within the group when encountered on an authorized member of the hunt group. It is checked during the hunt before moving to the next line in the hunt sequence. Calls to a line’s private DN are still permitted, as are call originations.
No Answer Advance
The No Answer Advance feature can optionally be assigned to each Hunt Group’s pilot DN. When a hunted-to station does not answer, this feature causes a resumption of the hunt from the non-answering station’s position following the defined hunt sequence for the group.
The CDRs (Call Detail Records) generated by Lotus Sametime Unified Telephony provide rich information about calls to a MLHG (Multiline Hunt Group). They allow to reconstruct the related calls, i.e. to have complete knowledge of each call from the time it enters the hunt group until it is successfully handled or missed.
The night service feature permits to route calls to predefined night stations or other answering devices - for example, to voice messaging, to an automated attendant application, or to a night bell device.
Subscriber Rerouting Interaction
A HG (Hunt Group) can be configured to allow or deny Subscriber Rerouting to take place for its members. If it is allowed, Subscriber Rerouting takes precedence over the HG distribution logic, otherwise only the HG distribution logic is applied.
How to Create a Hunt Group
This procedure describes how to create a HG (Hunt Group). Note that Hunt Groups are BG (Business Group) objects, i.e. all subscribers in a Hunt Group have to reside within the same BG.
How to Edit the Member List of a Hunt Group
This procedure describes how to configure the member list and individual members of an existing Hunt Group. It is possible to add/remove members to/from the list, to edit existing members and to change the positions of the members in the list.
How to Edit a Subscriber's Hunt Group Memberships
This procedure describes how to edit the Hunt Group memberships of an existing subscriber. Because subscribers may belong to several Hunt Groups, a subscriber can be added to / removed from several Hunt Groups at the same time.
RTP System Parameters for Hunt Groups
Certain aspects of the Hunt Group service are controlled on a systemwide basis by RTP (Resilient Telco Platform) system parameters. Any changes made to these parameters affect all business groups and their members. Typically, these parameters are set during initial system configuration, to enforce global system policies and ensure proper feature interworking.
Feature Access Codes for Hunt Groups
Feature Access Codes enable Hunt Group members to influence the hunting logic from their endpoints. A Feature Access Code can either be dialed or it can be assigned to a function key on the members' phones.
Keyset Operation Modes
Solution Comparison: Hot Desking versus DLS Mobility
Night Bell Call Pickup
Call Forwarding on Busy (Station-controllable)
How to Provision the Night Bell Call Pickup Service