Confusion about lines/accounts and Call Park


Bear with me as I try to explain my situation. The hardware is a UCM6104 running and a GXP2160 running (Yes I should upgrade everything one of these days…).

A client called up with the complaint that: 1) a call came in and was answered; 2) a second call came in; 3) the first call was put in Park (701); 4) the second call was answered; 5) the operator tried to put the second call in Park (702) but it wouldn’t go.

I think I know why: the Call Park key being used was assigned to a different account than the call that was trying to be parked. What I don’t understand is how I should set things up so this doesn’t happen.

Background: the UCM has “Use parklot as extension” set, and the phone has two MPKs set to Monitored Call Park, one for 701 using Account 1, and one for 702 using Account 2. The phone has four accounts assigned but while I originally had “Transfer on Busy” on each account set to forward to the next account, for some reason I removed that.

I think that the second call is coming in as a second call appearance on the first account, but the second call park slot (702) MPK is set to use the second account. I can solve the problem by simply setting both Call Park MPKs to use Account 1. I probably should also change the phones to only use a single line/account each.

My question is: what is the right way to set this up? Do you set up one line per phone or multiple ones (given a simple one-DID connection)? If you set up multiple lines, do you set up Forward on Busy from one line to the next? What is the best way to deal with the limitation that Call Park MPKs are bound to a single account?

Sorry for this long and probably confusing post. Any wisdom will be much appreciated…



Just my guess: can you try MPK set as dtmf ? AFAIR you should have option for all accounts :slight_smile:


Perhaps an explanation of what is what might help.

Lines can be thought of as call paths. The number of call paths is dependent on the phone’s capabilities.
Accounts are the mechanism used to define to what extension the phone is assigned.

So, while you may only have a single account associated to a phone, you can have multiple lines/call paths. This might be used for an attended transfer or for a 3-way call. With many phones you can have multiple accounts and multiple lines to each account. And finally, you can have the same account registered multiple times from the same phone and then assign more lines.

The issue, as you have discovered, is that the functions of the BLF/DSS/VMPK keys may/can also be tied to accounts. So, if a call came in on account 2 and an attempt was made to park the call using a key that was associated to account 1, then the system is not able to accommodate the request as there is no additional call currently tasked to account 1.

As Marcin points out, you can use DTMF to park a call and then it will not matter about the button account association. Of course, you will have to listen to the system prompt to know where the call was parked.

I suspect that you set up the accounts as there may have been some limitations with the firmware in use on the UCM. I assume that this was your mechanism of allowing an receptionist to handle multiples simultaneous calls. Given your post I am now somewhat intrigued as to how the system handles the messaging. Its been awhile since I looked, so I have some spare time today to do a little testing.


Just when I thought that I might have a somewhat easy day and could tinker a bit, it did not happen.

In any event, I was able to set up a 2130 and using the settings I normally do, was able to get the results I think you are looking for.

I have the phone set for only one account, The other 2 keys (line) are simply set to line and account 1. I then set up 3 of the physical keys to Park, 1, 2, & 3 using 701,702 and 703.

I can then handle 3 incoming calls as the calls will use the line keys. While actively talking with one of the calls, I can then use the soft key “park” whereupon the system will announce the position and then place the call in the spot. The BLF key setup earlier will reflect the spot 701 as being occupied and I can press the BLF to retrieve. UCM running & GXP2130 running

I did notice some quirkiness in some of this, but I got pulled away from being able to digging into it. I hope I can get back to it tomorrow.


I was very imprecise about the terminology but I think I pretty much understand lines/accounts/call paths. Call paths are the same as call appearances, a term used in some of the documentation. Sorry that I wasn’t as clear as I should have been.

I don’t think setting a MPK to DTMF will work for me because half of the purpose of the button is to show the status of the parking slot.

What’s still unclear is the exact behavior when multiple calls come in to a phone. I didn’t know you could assign several MPKs to Line/Account 1, and it’s not clear what happens. I think the GXPs are limited to two call appearances on an account, or maybe one more call appearance than there are accounts.

When I installed the client’s phone system none of this was clear and I set up the receptionist with four extensions/accounts, with each forwarded to the next on busy, and all other phones with two extensions/accounts forwarded the same way. I’ve since removed the Forward on Busy entries. What I don’t know is whether I should just cut back the phones, including the receptionist’s, to just a single extension/account. I think that would still let them have multiple calls going. It would also mean that all active calls would be on Account 1, so all Call Park slots would be associated with Account 1 too. Is this a reasonable way to set things up?

Thanks all for your help. The whole problem of how one best sets up phones with multiple accounts available has never been clear to me.



Sorry, was out of town over the past week.

In any event, a call path is meant to define a single call. As an example, you may have a single account with a provider and using a single trunk and a single DID, may be able to accommodate 23 simultaneous calls. Therefore, you have 23 call paths.

The same scenario extends to mult-line capable phones. You may have a GXP2135 that can support 3 accounts or it can only have one account and the other two keys are associated to line 1 (the one with the account registration). So, in effect, the phone can accommodate 3 simultaneous calls. As far as I know, the only limitaion as to the number of calls that a given phone can handle is limited by::

  1. The user’s ability to effectively manage the call volume
  2. The limit of the PBX to handle the number of calls to all extensions to the point that it can’t send more to an extension
    3, The limit of the phone’s account/line capability.

Yes, you can have them as I outlined in my original explanation using a 2130. I had one account registered to the UCM and all 3 keys set to account 1 The phone could then accommodate 3 calls coming in. The phone will show the calls coming in on the display and you then have the option of what to do with them- to include park.

I am not sure where you got the understanding of DTMF keys. I indicated " then set up 3 of the physical keys to Park, 1, 2, & 3 using 701,702 and 703.", meaning call park or monitored call park.

I would only use 1 account and then set the number of line keys to the same account but only so many as is believed the person manning the phone is comfortable in thinking they can handle. Set the other line keys to something other than account 1 so they won’t ring. Then, using the physical keys you have on the 2160 set up the park keys using as many as you may have a need for.


I was busy the past week as well and am just getting back to this, so your timing was perfect.

It sounds like my plan to get rid of the extra extension numbers I’ve been using on most of the phones is the right one. It just confuses people and now I understand that it is not necessary to allow multiple call appearances.

My understanding of DTMF is that it will send the tones you’ve entered (say, 701) using the SIP method that has been configured. So pressing a key assigned to DTMF does exactly what just pressing the 7-0-1 keys would do, And no more.

I’ve been setting Call Park MPKs to “Monitored Call Park”. This lets you park a call or pick up a parked call just like dialing the Parking Lot extension would do. But it also shows the status of the Parking Lot extension, so you can see if there is a call parked there. It’s very helpful. I’m assuming here that “Use Park Lot as Extension” has been enabled.

Sorry if I’ve been simplistic in my description, but there seems to have been some sort of miscommunication about this. If my understanding is incorrect, or there is some advantage to using DTMF that I don’t see, please let me know.




Actually, using a call park key is not the same as sending DTMF. While the end result may be the same, the call park key sends no tones, but rather sends an INVITE to the UCM which puts the call on-hold. This is followed by a REFER message sent from the phone telling the UCM the park spot (yes, using extension numbers) to use. The UCM responds back with a 202 (Accepted) and follows-up with NOTIFY messages to those extensions subscribed to receive the call park notices so that they will reflect the status in their BLF keys. So, if using the call park key, there is only a single key press. Using the DTMF requires the transfer key followed by the extension number. Conversely, you could use the #72 and let the system park the call for you whereupon the system will announce the spot used. Pressing the call park key where the call was parked results in an INVITE being sent to the call park extension (701 in this case) and the call is recovered.

The monitor call park function is used by a different IP-PBX (3CX), but appears to function the same when using the UCM. I have not looked at a trace to see how they differ in their messaging, but in my testing I saw no difference in functionality. I was using a GXV3275 to test with and it is on the latest firmware 3.184 Beta and is does not have a monitor call park setting, only call park. I was using a GXP2130 in earlier testing which does have the monitor call park and also requires a change to the dial plan to function correctly with 3CX.



Monitoring and using VMPKs for monitoring and sending calls to Call Park has confused me I must confess. The way I do it, and it seems to work, is to set the VMPK to BLF on 701, 702, etc and leave the Call Park settings in default mode (i,e, not set them to be extensions).

What is the “proper” way to set Call Park monitoring up in you opinion?




I use various methods as it really depends on the phone make and model and how many keys they may have.

In general, in the UCM I set the system to use the call park range in the defaults - 701 to whatever. I also use the use parklot as extension setting. Then, using the phone’s BLF keys, I set same to “call park” with Text to say Park1, Park2, etc. and then for the string or setting I input the 701, 702 etc. as the specific spot where it will be parked and others will have their buttons lit according to the status of that spot.

If the client has a mix of phones, I will then label them as Park 701, etc. but otherwise if the same make and with the keys needed, I just do 1, 2, etc. so as to make it shorter as it really isn’t important to know which extension given that they will be using a key, but still not too hard to assimilate 1 as being 701, 2 as 702.

If the client has a mix of phones (to include analog) and some without the display or needed buttons, I usually opt for the DTMF of #72 (manually input or a speed dial if available) so the system will handle and announce. This prevents others from trying to park in a spot that may not be vacant.


Hi So you set the phone to call park and use 701 etc, what about using option blf? … the other thing is while call is in call park position in order to retrieve call from call park you can not just pick up the call park when you raise the handset and hear dial tone… in other words the phone can not be off the hook… anyway to have it pick up a call in call park by just pressing blf key or vmpk ?


it’s a post from 2 years ago, better open a new one with details and questions