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UCCX - CallBack Feature



We have a question for the limit of calls the callback feature support if any.  Can anyone answer this question, your assistance is greatly appreciated.



VIP Collaborator

On UCCX - 400 agent OVA with a basic loop application controlling the callbacks and set to 2500 steps, I had some threshold testing at the start. Now I have some extra processes involved so numbers can differ based on many variables, but I had two different tests for calls dropped:
Quantity - in a 10 minute windows I was able to have between 60 and 70 calls in the loop before i consistently had one dropping.
Duration - 8 hours 25 minutes with 10 calls in the queue loop.

Again, these were just my numbers, and I have mutiple variables, a visual based queue gadget showing the calls waiting, etc. So other scripts could vary alot.

Can you please share a UCCX editor screenshot?


I love it, thanks for sharing this information. I always wondered what were the real limits.




Unfortunately, these numbers are actually meaningless without access to the scripts used.  In fact, Mike was stating he's doing quit a bit in the loop construct for other purposes, which consume steps that would otherwise be allocated to more queue time.  I'd wager more callback scripts in the field are not doing as much as Mike is doing, and instead, are simply looping a menu/get digit string to ask the agent to press a button on their phone.

If a loop consists of 10 steps, and one loop cycle takes 10 seconds, you're going to be burning 60 steps a minute, or 3,600 steps per hour.  With a max steps setting of 2,500, you're looking at a max queue time before aborting the contact of about 45 minutes only.

Contrast that with a smaller loop of 5 steps, and an increased cycle duration of 20 seconds, and you're immediately jumping up to about 3 hours.  That's a big difference in max queue time, but seemingly inconsequential on the scripting side.

There are three problems with the callback solution everyone does in UCCX:

  1. There is an imposed finite number of steps any one task can execute.  The default is 1,000, and you're advised not to change it unless instructed to by TAC, but a lot of people change it, and I have seen it as high as 10,000 and wouldn't even bat an eye.
  2. There is a required polling structure you need to build in order to overcome the fact that UCCX doesn't actually have a callback feature, because in order to connect the Agent to the customer, you need to know when the Agent actually answers the call, and the only way to do this, is to keeps asking "Are you there?" over and over again.  This could be as simple as a looping menu, but sometimes people put more steps in this loop like Mike is doing.
  3. There is a CUCM setting, which I'd imagine most customers don't know about or mess with, which limits all calls to 12 hours, so no matter what you do in UCCX, you couldn't say queue a call for callback the following day.  At least not in the callback way being discussed here. APIs and Outbound campaigns notwithstanding.

Also, the OVA template or the number of ports configured or the number of licenses installed, has no bearing on how long you can queue a call.  It does matter for quantity of callers in the system, but that is going to vary a lot based on what other things you're doing with UCCX and how you configured your CCGs.  The only thing that's different about a callback call, is that it consumes 2 ports in UCCX while queued, but at the benefit of freeing up a PSTN trunk.