CUCM Hunting

• The Unified CM cluster supports a maximum of 15,000 hunt list devices.
• The hunt list devices may be a combination of 1500 hunt lists with 10 IP phones in each hunt list, or a combination of 750 hunt lists with 20 IP phones in each hunt list. However, an increase in a number of hunt lists can require increasing the dial plan initialization timer specified in the Unified CM service parameters. Cisco recommends setting the dial plan initialization timer to 600 seconds if 1500 hunt lists are configured.

<note important>When a member is added to a line group (hunting), any call forwarding behaviour is ignored. This is to avoid the call from forwarded instead of going to another member</note>

• Perform digit manipulation
• Specify max hunt timer after which the call is returned
• Hunt Exhaustion or Timeout
  • Final forwarding setting to a final number
  • Configure to use personal preference setting to return the call back to the user and the behaviour will then be determined by the user Call Forward No Coverage option.

• Prioritized list of Line Group
• No digit manipulation

• Contains extension
• Distribution algorithm
• Ring No Answer Reversion (RNAR) - timeout on how long to try a member in a line group

<note important>CTI ports and CTI route points cannot be added to a line group. Calls cannot be distributed to endpoints controlled through CTI application e.g. CRS, IP IVR etc</note>

• Try Next Member, Then, Try Next Group in Hunt List (Default)
  • Sends the call to idle or available members. If no more members, try the next line group of the hunt list. If no more line groups, hunting stops
• Try Next Member, but Do Not Go to Next Group
  • Sends the call to idle or available members. If no more members, hunting stops.
• Skip Remaining Members, and Go Directly to Next Group
  • Sends the call to next lie group. If no more line groups, hunting stops
• Stop Hunting
  • Hunting stops

• Top down
  • Always start from the top, hunt for next idle and available members. (Next call to 1000)
• Ciruclar
  • (n+1)th member where n is the member to which CUCM most recently extended the call. (Next call to 1003)
• Longest idle time
  • Idle members only, from most to least idle. (Next call to 1000)
• Broadcast
  • All idle and available members simultaneously. (Next call to all directory nubmers)

• RNAR
  • How long to ring a member before moving to the next.
  • Default is 10s.
  • If Hunting timer expire, then RNAR is ignored.
• Add members

• Forward Hunt No Answer
  • When at least one member rang but did not answer
• Forward Hunt Busy
  • When none of the member ring as they are all busy

• On the line of the device, configure Call Forward No Coverage