Solved Occasional paging calls become stuck

[TTHandH]

Hello, we page a lot in our retail store and at least a few times a day the paging call becomes stuck. The prevents us from paging and all the phones are considered busy. Is this a glitch? Thanks for any help.

 

[KyriacosS_3CX]

Hi,

Can you provide some info on what the setup is? Type & version of 3CX install, how phones are connected, what phones are being used? What's your process for clearing this state?

 

[TTHandH]

Hi,

Can you provide some info on what the setup is? Type & version of 3CX install, how phones are connected, what phones are being used? What's your process for clearing this state?

Sure, 3CX hosted
Version 20.0 Update 8 (Build 1109 Release)
All Fanvil phones. Most are X6U v2 with a five X5U v2 and one Fanvil PA3 paging adapter for overhead analog paging speakers. All devices have the latest 3CX recommended firmware.

 

[Charles_3CX]

Are all the devices that are pages using the latest firmware and are provisioning behind a 3cx SBC?

 

[TTHandH]

Are all the devices that are pages using the latest firmware and are provisioning behind a 3cx SBC?

Yes, latest the firmware and behind our 3CX SBC. All devices are located at a single site.

 

[Charles_3CX]

How many phones are behind the SBC, please, and is this a dedicated machine for the 3CX SBC with the right amount of specifications?

Additionally, how many phones are treated by the page at any given time?

 

[TTHandH]

How many phones are behind the SBC, please, and is this a dedicated machine for the 3CX SBC with the right amount of specifications?

Additionally, how many phones are treated by the page at any given time?

68 phones. It is not a dedicated machine. The SBC was setup on a workstation when we just had 5 phones to test 3CX to see if that was the way we wanted to go. I can set it up on a dedicated machine with those specs. We have several paging groups, and one has about 50 phones on it. The other two have 17 phones on one and 7 phones on the other. I haven't seen it lock up on the paging group with the 7 phones, but it could have. I guess I also just didn't understand the importance of the SBC in paging, so, I'm guessing my next move is to move the SBC to a dedicated machine with the appropriate specifications?

 

[Charles_3CX]

Yes, this is highly advised. Ensure that the phones each have a maximum of 10 BLFs, and the machine used for the SBC is dedicated solely to the 3CX SBC. It should have only one network card, with specifications exceeding those recommended for 100 phones, whether Linux or Windows.

 

[TTHandH]

Yes, this is highly advised. Ensure that the phones each have a maximum of 10 BLFs, and the machine used for the SBC is dedicated solely to the 3CX SBC. It should have only one network card, with specifications exceeding those recommended for 100 phones, whether Linux or Windows.

Ok, I'll do just that thank you for your help. Most of our phones have more than 10 BLFs, if I might ask, why does having more than 10 affect the system?

 

[KyriacosS_3CX]

Ok, I'll do just that thank you for your help. Most of our phones have more than 10 BLFs, if I might ask, why does having more than 10 affect the system?

Regarding the 10 BLFs, this is generally mentioned in a few places, but a quick summary is that it takes a lot of processing and bandwidth to keep track of them all, as BLFs are in constant communication in order to keep up to date. A fast network and a strong SBC will let you have more, but at some point you might be better off using more than one SBC and limiting the BLFs flowing through each one.

Once you move your SBC to the dedicated in-spec machine, if you are not facing any issues leave the BLFs as they are - but still keep it in mind in case you expand your user base. SBC specs are made with an expectation of up to 10 BLFs per connected extension but a lot depends on how active the site is generally.

 

[TTHandH]

I went back and reduced the amount of BLFs and Shared parking spots to around 10 total. That did seem to help some and after some research, the machine that we had the SBC on was woefully under powered. I'll work on a update to spec workstation for it. Thank you to Charles and Kyriacos for the help and info. I appreciate it!

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[TTHandH]

I wanted to give an update on what turned out to be the solution to our stuck paging calls.
It turns out that they weren’t stuck paging calls after all, it was our employees forgetting to place the calls on shared parking before hitting the BLF key for one of our three paging ring groups. We had initially set up BLF keys to be blind transfers but after I changed the option to attended transfer, our problem was solved. Hope this update can help anyone else to not go through this as well. Have a good day, guys.