DAHDI Config 24B channels?

Anyone know how to specify for a Digium 4 Port T1 Card to use all 24 channels on a SPAN? The reason I ask, is we have 1 PRI, and 3 channel banks, and each of the channel banks uses all 24 B channels for use with old cheap analog handsets. We have an 11 year old version of asterisk we are looking to upgrade and use FreePBX for the graphical simplicity. But the DAHDI config tool only allows us to use 23 B channels for each span. Our current system uses channels 25-96 all as fxoks. Any thoughts?

What you said confused me a little bit. It sounds like you are actually describing three T1/DS1 lines with 24 channels each, not three PRIs (which DO have B-channels).

Could it just be a problem with terminology? If the old lines were connected to channel banks, then they should be 24 POTS DS0 lines, not PRI B-channels…

You probably shoudn’t rely on the Dahdi Helper here,. Your current working span and channel definitions , either dahdi or zapel, can just be used in your new machine. A quick google to see the name changes of zaptel is used on your working box.

We’re actually waiting for the new version of FreePBX to be generally released. We are virtualizing the FreePBX server on Windows 2016 Server with Hyper-V and the new 4 port T1 Card that has Discrete Device Assigment or PCI Pass through as I like to call it, to the VM. We can configure it, we were just hoping the “Dahdi Config” tool in the web interface of FreePBX would allow us to use all 24 channels on a span as B channels instead of just 23.

I guess worst case scenario, I can upgarde a couple of analog phones to be SIP, and just not have the last channel in each bank be used. But if anyone knows another way, I’m all ears.

There aren’t 24 channels on a PRI span - there are only 23.

No that won’t work, the signalling needs to be span specific, so your span 1 is a PRI but the other three are good old T1 RBS ones, so you will need FXO/FXS/E&M whatever to have dahdi present them to Asterisk.

I have just enough knowledge to be dangerous when it comes to the terminology sometimes, so you are probably correct. :wink: We have 1 PRI, and the other 3 devices are Rhino Channel banks FXS as they provide voltage to the phones. There is a single RJ48 port on the back of each unit used to tie into each span of the T1 card on the asterisk box. But for the life of me, the web based Dahdi Configurator tool in FreePBX will only let me use 23 channels on a span, and have to reserve the last.

Yeah - the tool isn’t going to hack it. It just isn’t flexible or sophisticated enough to handle your configuration. It wants to be helpful, but it just isn’t going to be able to do it. Think of it as the 8-year-old little brother of VOIP software. You want it to succeed, but it just isn’t going to.

I’m afraid you’re going to end up crafting the config files by hand and locking them down. The good news is that they never change, so once you get the working, they write-only memory.