[asterisk-users] Point a Digium phone to a configuration URL using mDNS without DPMA or DHCP option 66

[Alex Villací­s Lasso]

I have the following scenario. A small network has DHCP but does not publish option 66. An Asterisk server is on the network, but the Asterisk version does not support DPMA and it is hard to switch the version. However, there is a possibility to have a web 
server and an mDNS (Avahi) server. I have been reading about provisioning Digium phones without DPMA, and it mentions that option 66 can specify the URL prefix to use for the XML configuration. Is there a way to specify the same through Avahi mDNS? 
Something along the lines of this (of course this does not work, but gives an idea of what I am looking for):

<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
     <name>Digium Phone Configuration Server</name>
     <service>
         <type>_digiumproxy._udp</type>
         <port>443</port>
<txt-record>config_server_url=https://10.0.0.145/provisioning_scripts/http_provisioning.php?authhash=XXXXX&amp;filename=</txt-record>
<txt-record>serviceType=configuration</txt-record>
     </service>
</service-group>

I want the phone to request "https://10.0.0.145/provisioning_scripts/http_provisioning.php?authhash=XXXXX&amp;filename=/001915abcdef.cfg".