Oh my goodness you have been sent down the mother of all rabbitholes.
The CP-8841’s do not run SCCP. Cisco has actually deprecated that protocol. They run SIP. I don’t even think there is SCCP firmware available for those phones.
Plug your phone into a PoE port and while it’s at the grey screen saying provisioning, press the gear button and then go to Phone Information and it will show what Enterprise firmware is loaded on it. You will likely see sip in the name, there.
The OLDER phones like the 8_NINE_41’s (8941) and the other x9xx model phones are the ones that run SCCP firmware. However, Cisco did release SIP firmware for them (now, unavailable since Cisco deprecated those phones - unavailable from Cisco that is but still available from your favorite Russian pirate site, lol)
But the 88xx’s and 78xx models run SIP and you can simply create a generic pjsip extension for them and go to town. However, I don’t think anything other than straight calling works on them because the SIP firmware on those phones is “Ciscoified” meaning the call control (forwarding, message lights, etc.) is completely alien to how Asterisk/FreePBX does it.
Now, how do you get the BLF functions working on those phones? Simple. You have 1 of 3 options.
Option #1 is to patch Asterisk in FreeBSD. There’s 2 ways. First is to setup a straight Asterisk system and apply the usecallmanager patch to that. Meaning, recompile asterisk. Then follow the advanced guide on the Sangoma help site to install the FreePBX GUI on top of that:
The second way is to install FreePBX and it’s version of Asterisk then download the FreePBX rpm’s and patch them then recompile FreePBX’s Asterisk. The current usecallmanager patch seems to patch chan_pjsip not the older antique sip so ignore the cautions you see in older posts on this forum. The instructions to do that are here:
[2023 FULL GUIDE] Applying UseCallManager Patch for FreePBX - YouTube
and here:
Option #2 is to buy the licenses for the 3PCC firmware from Cisco and replace the Enterprise firmware with 3PCC. The firmware license is inexpensive, under $50 if you get it from a large Cisco reseller like CDW. It puts a webserver on the phone and you can configure the phone with a web browser like any Polycom or other phone, no need to muck about with XML files. I will put some more info on this at the bottom of this post.
Option #3 is to use SCCP per the following:
Warning though - those instructions are older. They may not apply to current FreePBX. But supposedly that driver has now included SIP support and works with the x8xx phones. I have never tried it, as I think the focus has been to use it for the older SCCP phones.
An interesting comment in this thread here:
Register Cisco Phones after SCCP Manager Install - FreePBX / Endpoints - FreePBX Community Forums
is:
“The Asterisk folks I’ve talked to lately want to stress that Cisco (especially 79xx) phones using the SIP Image should be outlawed. I support that position. They are, without exception, the hardest phone to configure and working reliably, and even once installed still don’t work as well as the phones in Skinny mode.”
Sadly the issue with Option #3 is that the biggest supporter of the Chan-SCCP approach died a couple years ago. You are going to have to do some more digging to go that route with old phones. But, I think you are better off with the newer phone you have, anyway.
Assuming you got your 8841 off Fleabay, where right now the average cost of those is running under $30, that plus the license file for 3PCC is really NOT a bad deal for a videophone. And since Cisco just announced EOL for those phones, it’s likely that the price of them is going to crash on the Fleabays of the world and we will be awash in cheap videophones.
I have a site of over 300 Cisco phones of various x8xx models and I estimate cost of shifting them to 3PCC is likely going to run us somewhere in the neighborhood of $20k but I’m still favoring doing that if I can use the phones with PBXact instead of having to pay Ci$co for a new UCM or go to webex cloud calling (ick)
The sites that really should be seriously considering the usecallmanager patch are the ones who have a large number of older SCCP phones and the willingness to reflash those to Enterprise SIP because the older phones CANNOT run 3PCC firmware. You can buy refurb Cisco 8945’s off Fleabay in quantity for $11 a phone, so if you are willing to go that route, you can really have a slick FreePBX system for very little money. Or, with more work, consider the SCCP driver and leave the phones running the SCCP firmware.
The irony of it to me, personally, is that when I was younger and had no money but plenty of time, the cost of Cisco devices, even the older SCCP ones, was far beyond my reach to justify buying them and messing about with the callmanager patch. But today, I’m older, and have a big budget, and the newer and older Cisco phones are cheap as dirt, but now I can’t justify buying them because my time cost is too high to fool with them. Sometimes the Universe she likes to play jokes on us. Sigh.
But, if you DO want to go down the usecallmanager or chan-sccp patch road with dirt cheap Cisco videophones that cost $11 a phone, I’ll be green with envy. There’s even a provisioner someone wrote for the Enterprise phones that is much slicker than EPM for these phones:
Cisco Provisioning Manager - Create Device (FreePBX UseCallManager) - YouTube
Now, getting back to your phone - if you do go forward with buying the 3PCC license from Cisco for it, instructions are on Cisco’s website as to how to upgrade the phone - you take the license key, load it into Cisco’s website along with the mac address of your phone, and then log the phone into Cisco’s site where it downloads and installs the key and the firmware. I won’t go into that further, Cisco explains it well.
Once it’s upgraded, then getting it to work on FreePBX is easy. Sangoma DID have a document for doing this but sometime during the last couple days - it disappeared off their website. They are messing with that site. To find it, search Bing for:
“use cisco 3pcc phones on FreePBX”
the first listing is this link:
But right now - it’s broken. You can pull the document out of Bing’s cache.