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CP-7821 register with SIP



I have a Cisco CP-7821 model POE IP phone, I wanted to use that phone to get registered with SIP.

I have performed the following steps for that

1) Downloaded the latest Cisco IP Phone Firmware sip78xx.11-5-1-18

2) Downloaded third Party TFTP Server SolarWinds TFTP Server

3) have placed the required files in the TFTP root directory.


I am getting an error as unable to download ITLFile.tlv, ctl.tlv and ITL.tlv files.

Please find the attached configuration file.





These are images for the MPP variant ( .


What's the current software version on your phone?

Cisco Employee


Based on the info in your post you are using a "enterprise" phone meant to register against CUCM, CME or HCS. You can quickly verify by checking the SKU on the back of the phone. If it misses 3PCC in the SKU name (e.g. CP-7841-3PCC-K9=) then the phone isn't properly registring against Asterisk/Freeswitch/Broadsoft/...

If it is a Cisco MPP phone (with a SKU mentioned above containing 3PCC) then we support these configurations and have a full list of features including ACD, Voicemail, Group Pickup, BLF, etc,..

If you go to the MPP (multi platform phones) section on CCO you can find the admin guides (including examples). MPP firmware is available on CCO (current load is: 78xx.11.0.1.MPP-477 or 88xx.11.0.1.MPP-477).

The phones can't switch from an enterprise firmware to a MPP load.

just a quick question… Did the support change? I have a CP-7821-K9 that I would really like to connect via SIP to third party callmanager. Is that possible or can I only connect it to a cisco CUCM?

Hi Hannes,

For now no, the only MPP phones that run against 3rd party Call Control are the phones with 3PCC in the SKU (product name).

On the back you will see a sticker saying something like:

CP-7821-3PCC-K9= (an MPP phone) or CP-7821-K9= (Enterprise phone for registering against CUCM/HCS). We have gotten request several times for addition to the roadmap so we are investigating.

Leo Laohoo
VIP Community Legend

Phones running enterprise-firmware can be configured to a non-Cisco CUCM, like Asterisk or 3CX.
I just want to warn you that it can be difficult and/or tricky at the start but once you've gotten a phone through the others will be easy.

Hi Leo,

The question was did the support change (so is it supported and works properly). 

Enterprise phones from the 78xx/88xx series are not supported on Asterisks. Could you reverse engineer some parts of the config to get a phone to register on Asterisk and get very basic telephony, yes you could. The challenge is this is not supported, documented and has 0% guaranty it will work or keeps working.

Enterprise phones use SIP signalling but we have extra extensions that create the full experience with all  the features of CallManager (CUCM). Every firmware update will potentially break the operation of the phone and like I said their is no proper way to get certain elements configured on the enterprise phones without a CUCM.

Phones running MPP firmware are the only phones we currently produce and support for 3rd party call control (that includes Broadsoft which has been acquired by Cisco last year).

Running this firmware you have normal access to all the features using either the WebUI, PhoneUI or XML and is fully supported by TAC

So for now CUCM and HCS require a 78xx/88xx running enterprise firmware. 3rd party call control requires mpp firmware for the 68xx/78xx/88xx series

Well thanks for the answer. At the end of the day the phones should only register to my LANCOM Callmanager and to basic telephony. We don't need any "fancy" stuff for the moment just receive and place calls ;)

Is that possible or not? ;)


If not is there a possibilty to get a CUCM license (like a DEMO) for at least 3 months? 

Leo Laohoo
VIP Community Legend

I know there are stuff in this forum/communities about 78XX and Asterisk. The "basic" features, aside from receiving and making calls, are:
1. Transfer call
2. Hold
As what jeboer said, this direction is not supported by TAC and any Cisco documentation.

So what i got from this is:

I can upload a config file and make the phone registering itself with my CM and also I'm able to place and receive calls. Thats all I wanted to know ;) so I don't need to change the firmware etc. "just" configuring the XML is enough?

Leo Laohoo
VIP Community Legend

The SEPmacaddress.cnf.xml, dialplan.xml are enough.

Thanks a lot Leo Laohoo for your support.


Got my Cisco phones up and running with doing simple calls between each other and out into the normal network via SIPGATE which is totally fine for my scenario right now.



Kind regards 



Leo Laohoo
VIP Community Legend

Hi Hannes,
Thanks for the update. We are happy it's finally working.
Can you please post the SEPmacaddress.cnf.xml (minus the passwords and IP addresses) so it can/will help people with similar issues/questions.


I've currently run into the same issue and was hoping there was a .xml template ( minus passwords / IPs ) that I could clone and revise.  If I could have it sent to the email acct below that would be gr8.





Read my responses to this thread. I have already included a link to download a known working SEPmacaddress.cnf.xml.
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