Cisco 7942s

mdoupe

New Member
Mar 21, 2023
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Hi all,

Shot in the dark (this was posted with no resolution earlier) but I have a multi-tenant FusionPBX that I am trying to register Cisco 7942's to. The Cisco phone tries to register to <ext>@<PBX IP> instead of <ext>@<PBX FQDN>, and freeswitch rejects it. I do not have the IP listed anywhere in the provisioning file, only the fqdn.

Has anyone ever solved this? Is there a way to "default" ip registrations to a specific tenant? or a way to mangle sip packets to change the registration address? If I buy support hours, would the official support be able to help with this in any way?

Thanks!
 
Hi @mdoupe,
I’d recommend starting by double-checking the Cisco phone itself—make sure it’s actually picking up the configuration you’re pushing, and see if the SIP server is showing the correct FQDN on the phone. Once you’ve done that quick sanity check, you can run a Wireshark capture to see if the phone is sending SIP packets with the FQDN, or if something is getting overwritten along the way. If it looks like the FQDN is being replaced, you’ll want to dig deeper into the phone’s settings to prevent that. If the SIP packets show the correct FQDN but it changes further down the line, then the issue is likely elsewhere in the setup.


I can’t speak for FusionPBX support, so you’ll want to reach out to them directly to see if this falls within their scope, or if they have someone with deep SIP experience who can help.

At FS PBX, we do our best to go above and beyond for our clients, including troubleshooting things like this. If you ever need help on our platform, we’re happy to assist!
However, if you follow my advice above, you may be halfway there to fixing it yourself or at least narrowing down the issue. Post your results and findings here, and I might be able to help further.
 
Yep, I've made sure it's picking up the config. I've done a pcap, it's sending the IP in the request, not being overwritten at any point.
 
Also, make sure you have the correct firmware on that phone. Some Cisco phones ship with the firmware that is meant to work only with Cisco Voip Servers and some ship with firmware that can be used with any SIP server. I know that you can buy a license to convert from one to another
 
Yep, I've made sure it's picking up the config. I've done a pcap, it's sending the IP in the request, not being overwritten at any point.
I would dig more into the settings and find which setting may be responsible for this.
 
I can register this phone successfully via SIP on our current FreePBX server. I copied the firmware and provisioning file from FreePBX to FusionPBX, and modified the address, extension, and password. I put the phone on the FusionPBX vlan (where Yealink phones are working great). I can see it pull the provisioning file and then try to register using the modified extension via sngrep, but using the IP address instead of the FQDN I put in the provisioning file.

I've been through the documentation at https://usecallmanager.nz/sepmac-cnf-xml.html and I don't see anything that would tell it to use an FQDN or IP.
 
Asterisk and Freeswitch work a bit differently. So the config from FreePBX may not match what Freswitch is expecting. Freeswitch needs a domain passed for authorization. Try resetting the phone and manually enter the config parameters to register the phone. Once you find a working configuration you can adjust your provisioning file to pass that info.

Also, here is what I would try. Set up a SIP proxy setting in Cisco and point it towards your server in addition to your server settings? You may need to play with the ports and proxy/server settings to get it right but it should work eventually. I've successfully regirested Cisco phones to Freeswitch in the past
 
I can't seem to manually enter a line configuration. I've unlocked it with **#, but pressing select on a line does nothing.
 
If switching to admin mode is different than pressing **# in the settings menu, I don't know how to do it. I can't really find any solid info on google, either. Some people have mentioned an "Unlock Settings" menu option, but I do not have it.
 
I don't know if pressing those buttons is the same as switching to admin mode. I usually did it from the web. My notes say to navigate this URL. Not sure if they are up to date. It's been a while

Code:
http://192.168.x.x/admin/advanced
 
No, they don't. Search for something similar for your version. I'm not surprised that it changed since. It's been about 3-4 years. It could also be related to the particular model. This was for SPA phones.
 
Is all done with tftp and config files, I used these for years, they are good phones but terrible to work with on any thing other than call manager. Throw them away and get a proper ip phone.
 
Believe me, I would love to. Unfortunately, I need to make these work or we're not moving to FusionPBX.

I did manage to get my tester to send a register with the fqdn with an old firmware version (8.5.4) I found on github, but I seem to be having other issues now.

Link to the github in case it helps someone else: https://github.com/staskobzar/cisco_prov/tree/master/sip

I will post back here if I manage to get it to register properly.
 
I will probably have a conf file somewhere that I used to use, I'll see if I can dig one out.
 
I've just found this from 2012, it would definitely be for fusionpbx though:

Code:
image_version: P0S3-8-12-00
# Line 1 Setup
line1_name: "603"
line1_authname: "603"
line1_shortname: "DMM"
line1_password: "U.YokaH.21"
line1_displayname: "603";
proxy1_address: pbx05.mydomain.com
timer_register_expires : 60
# Phone Label (Text desired to be displayed in upper right corner)
phone_label: "Label1 " ; add a space at the end, looks neater
phone_password: "cisco" ; Limited to 31 characters (Default - cisco)
user_info: none
telnet_level: 2
nat_enable: 1
nat_address: "213.107.67.198"
voip_control_port: 5060 ; UDP port used for SIP messages (default - 5060)
start_media_port: 8000 ; Start RTP range for media (default - 16384)
end_media_port: 8012 ; End RTP range for media (default - 32766)