14 Fun Facts about CUCM 10.x Hunt Pilots and Native Call Queuing

She Loves Call Queuing

Lately, I've had a lot of talk about how the new features in CUCM 9.x/10.x related to hunting and native call queuing can enhance user experience within existing call flows.  But, nothing in life is free.

Cisco provides many limits and recommendations related to the use of hunt pilots and native call queuing that could potentially blow your super-fantastic-end-of-the-world design out of the water.  Much of what is listed below would not be learned by just playing around with the new call queuing feature - it's very much worth the time to read through the "additional information" link at the bottom of this post.

Below is a list of the fun facts related to native call queuing and hunt pilots in CUCM 10.x that I've been able to gather thus far.

14 Fun Facts about CUCM 10.x Hunt Pilots and Native Call Queuing

1. Call queuing is not supported with broadcast algorithm hunt lists.
• This makes sense in the conventional sense of a contact center that typically delivers the call to the longest available user.  
• The calls are required to be distributed to individuals based on the availability status of the user using a top down, circular or longest available algorithm.
2. You can configure a maximum of 25 hunt pilots per hunt list in Call Queuing. If you exceed this limit, the queue status will not be displayed.
•  Plenty for 99% of the applications out there.  I suppose you could find a place where this is a limiting factor - but then again, this isn't a replacement for UCCE.
3. If no line members answer a call, then that caller will not be placed in queue. The call is routed to a new destination, or disconnected, based on the setting under "When no hunt members answer, are logged in, or registered" .
• I assume that if a single line member does not answer, it will re-queue the caller in the way that a typical RONA would usually be handled. 
• I also assume that the maximum wait time for the hunt pilot is the ultimate trigger here.
4. Calls will be placed in queue only if all members are busy.
• Makes sense, if they aren't busy they should be able to take the call immediately.
5. If a line member does not answer a queue-enabled call, that line member is logged off the hunt group only if the setting "Automatically Logout Hunt Member on No Answer" is selected on the line group page.
• This is a good way to limit the impact to callers of someone that has walked away from the desk or left for the day in an "available" state.  I recommend that "Automatically Logout Hunt Member on No Answer" always be checked and ensure that users are trained quite clearly on how this works.
6. Queuing-enabled hunt pilot calls can only be received by line members one call at a time. Two queuing-enabled hunt pilot calls cannot be offered to a line member (no matter what the busy trigger is set to). This does not limit a line member to only receive calls directly to their DN or from non-queuing hunt pilots.
• On the surface this may seem like a limitation, but in a contact center-like environment you wouldn't want to have a line member bothered with multiple calls at the same time (typically).  
• This is one for the lab, but I wonder if non-queuing-enabled hunt pilots could deliver calls to a line member if they've already taken a queuing-enabled call (and their busy trigger will allow it).
• Furthermore, could a non-queuing hunt pilot configured to broadcast all users be used as an overflow for when a queuing hunt pilot did not find an answer? 
7. If the hunt list has multiple line groups then these line groups need to have the same setting for Automatically Logout Hunt Member on No Answer.
• Unsure what happens if you don't comply, but I can see this being a common configuration error.
8. All Hunt options need to be set to Try Next Member, then Try Next Group in the hunt list. 
• Again, unsure what happens when you don't comply.
9. H323 Fast Start does not support Call Queuing. 
• I'll need to find more clarification on this.  It can have a bearing if you have call handling groups located in various spokes from the CUCM hub.  Will it still deliver calls, just not in fast start mode?
10. Cisco Unified Communications Manager does not support Unified Mobility with Call Queuing.
• This policy seems to have been done with the caller in mind.  Remote team members can be reached mobile using more conventional coverage path techniques.
11. A single Unified CM Subscriber supports a maximum of 100 hunt pilots with call queuing enabled per node.
• This is both a limiting factor and a management headache in very large hub-spoke enterprises.  Requires being very mindful of how hunt pilots are spread throughout the cluster.
12. The maximum number of simultaneous callers in queue for each hunt pilot that you can configure ranges from 1-100 (default 32).  
• Should be more than enough for most environments.  If you're pushing this limit, consider the more conventional contact center products.
13. The maximum wait time in queue for each hunt pilot that you can configure ranges from 0-3600 seconds (default 900). 
• A maximum of one hour in queue is for the truly determined customer.
14. An increase in the number of hunt lists can require you to increase the dial plan initialization timer that is specified in the Unified CM service parameters. Cisco recommends you to set the dial plan initialization timer to 600 seconds if you have 1500 hunt lists configured.  
• Very large clusters beware.

How to Configure Native Call Queuing in CUCM

This great video from Paul Stryer, Cisco Architecture Systems Engineer, does a great job illustrating how to configure CUCM's native call queuing feature.  He also demonstrates with test calls in his lab, which really help to reinforce the concepts.



For additional information about how CUCM Native Call Queuing functions, I highly recommend you check out the limitations outlined in the Features and Services Guide for Cisco Unified Communications.