Update: I’ve taken packet captures of a phone’s traffic when it reconfigures. I see it request all of the phonebook XML files over HTTP, but never requests the blf-5.php (not sure if its supposed to). Here is the current config for this device in res_digum_phone_devices.conf:
[3468]
type=phone
full_name=3468 Debra B
parking_exten=70
parking_transfer_type=blind
active_locale=en_US
application=voicemail-pin
application=parking-app-default
line=3468
send_to_vm=yes
accept_local_calls=host
active_locale=en_US
call_waiting_tone=yes
display_mc_notification=no
firmware=D40-2_2_1_3
firmware=D45-2_2_1_3
firmware=D50-2_2_1_3
firmware=D60-2_2_1_3
firmware=D62-2_2_1_3
firmware=D65-2_2_1_3
firmware=D70-2_2_1_3
lock_preferences=no
login_password=22222
name_format=first_last
parking_exten=70
pin=voicemail
record_own_calls=yes
timezone=America/New_York
web_ui_enabled=no
use_local_storage=yes
contact=contacts-internal.xml
contact=contacts-5.xml
blf_items=blf-5.php?lines=1
blf_contact_group=5
network=network–1
network=network-4
network=network-3
network=network-1
8021x_method=
d70_logo_file=user_image_4.png
application=status-available
application=status-away
application=status-dnd
application=status-xa