Tools: http://www.grandstream.com/index.php/support/tools

P-Value Listing (partial, version and phone dependent): http://www.voip-info.org/wiki/view/Grandstream+Configuration+Tool

https://forums.grandstream.com/t/custom-ring-tones/35433

• On the PBX, set a custom alert-info header on the Inbound Route
  • Alert-Info to Custom
  • Custom Alert-Info to custom-ring
  • Provisioning
    • P1488=custom-ring
• On the phone, under Account → Call Settings → Match Incoming Caller ID
  • Matching Rule → custom-ring
  • Ringtone → Custom Ringtone 3
  • Provisioning
    • P1489=3

Grandstream phones auto-reboot endlessly if they don't like the configuration files.

Try performing a factory reset if you experience provisioning problems or follow the firmware update procedure:

1. Perform a factory reset
2. Update the firmware (may take a while)
3. Troubleshooting: Delete the provisioning template
4. Troubleshooting: Create a new provisioning template
5. Rebuild the config files
6. Do another factory reset

You can use:

• Provisioning
  • Config file
    • Basefile edit
  • P51=<vlid>
    • VLAN Tag (Ethernet)
  • P1685=1
    • Default Transfer Mode to Attended
• Manual
  • Web interface configuration

DHCP VLAN discovery does not seem to work but Option 66 does.

• DHCP Option 66 (tftp-server-name)
• DHCP Option 132 (vlan-id)
• Enable DHCP VLAN in config file (P8300=1, or P8038=1 in older firmware)

Here is an initial phone boot from the perspective of the PBX (TFTP server) with the phone booting on data VLAN.

• The phone switches to voice VLAN because of the configuration file
• It then gets a new IP on the voice VLAN

[root@ppmpbx ~]# tail -f /var/log/messages

Aug 23 15:23:02 ppmpbx in.tftpd[25787]: RRQ from 192.168.70.65 filename cfg000b8270f741
Aug 23 15:23:04 ppmpbx in.tftpd[25788]: RRQ from 192.168.70.65 filename cfg000b8270f741.xml
Aug 23 15:23:04 ppmpbx in.tftpd[25789]: RRQ from 192.168.70.65 filename cfg.xml
Aug 23 15:23:51 ppmpbx dhcpd: DHCPDISCOVER from 00:0b:82:70:f7:41 via eth0
Aug 23 15:23:52 ppmpbx dhcpd: DHCPOFFER on 192.168.71.68 to 00:0b:82:70:f7:41 via eth0
Aug 23 15:23:52 ppmpbx dhcpd: DHCPREQUEST for 192.168.71.68 (192.168.71.30) from 00:0b:82:70:f7:41 via eth0
Aug 23 15:23:52 ppmpbx dhcpd: DHCPACK on 192.168.71.68 to 00:0b:82:70:f7:41 via eth0
Aug 23 15:24:21 ppmpbx in.tftpd[25822]: RRQ from 192.168.71.68 filename cfg000b8270f741
Aug 23 15:24:21 ppmpbx in.tftpd[25823]: RRQ from 192.168.71.68 filename cfg000b8270f741.xml
Aug 23 15:24:21 ppmpbx in.tftpd[25824]: RRQ from 192.168.71.68 filename cfg.xml
Aug 23 15:24:23 ppmpbx in.tftpd[25825]: RRQ from 192.168.71.68 filename /grandstream/1/gxv3275fw.bin
Aug 23 15:24:24 ppmpbx in.tftpd[25825]: tftpd: read(ack): Connection refused
Aug 23 15:24:27 ppmpbx in.tftpd[25866]: RRQ from 192.168.71.68 filename gxv3275cust

This is a 'normal' phone reboot with phone already on the voice VLAN:

Aug 23 15:13:13 ppmpbx dhcpd: DHCPDISCOVER from 00:0b:82:70:f7:41 via eth0
Aug 23 15:13:14 ppmpbx dhcpd: DHCPOFFER on 192.168.71.68 to 00:0b:82:70:f7:41 via eth0
Aug 23 15:13:14 ppmpbx dhcpd: Wrote 5 leases to leases file.
Aug 23 15:13:14 ppmpbx dhcpd: DHCPREQUEST for 192.168.71.68 (192.168.71.30) from 00:0b:82:70:f7:41 via eth0
Aug 23 15:13:14 ppmpbx dhcpd: DHCPACK on 192.168.71.68 to 00:0b:82:70:f7:41 via eth0
Aug 23 15:13:41 ppmpbx in.tftpd[25386]: RRQ from 192.168.71.68 filename cfg000b8270f741
Aug 23 15:13:42 ppmpbx in.tftpd[25387]: RRQ from 192.168.71.68 filename cfg000b8270f741.xml
Aug 23 15:13:42 ppmpbx in.tftpd[25388]: RRQ from 192.168.71.68 filename cfg.xml
Aug 23 15:13:43 ppmpbx in.tftpd[25389]: RRQ from 192.168.71.68 filename /grandstream/1/gxv3275fw.bin
Aug 23 15:13:46 ppmpbx in.tftpd[25389]: tftpd: read(ack): Connection refused
Aug 23 15:13:47 ppmpbx in.tftpd[25390]: RRQ from 192.168.71.68 filename gxv3275cust

Phones auto reboot after requesting cfg.xml from the TFTP server when there are firmware compatibility, config file errors or provisioning problems.

To troubleshoot, you can manually edit the config file in a 'divide and conquer' method:

1. Make a backup of the problem file
2. Delete half of the file
3. Try it again

If you see Unfortunately, MPK has stopped., try another factory reset.

Insert a paper clip into the reset hole in the back of the phone. Press and hold for at least 7 seconds.