VoIP hardware is developing fast - this is where you ask all those “how do I make my SIP Telephone, Adapter or Asterisk box work with my voip provider?” questions.


By Sponsor
User avatar
By WelshPaul
The Cisco 79xx IP phone series support 2 protocols: SCCP (skinny) and SIP. By default the phones are working with SCCP. The way to get the Cisco phone to work with VoIP is to load the SIP firmware into the phone and then configure the extension. For this to work you need a TFTP server plus a DHCP with option 150 enabled – an option to auto-provision the TFTP server IP address when the DHCP server hands out the regular ip address to the phone.
Without an auto-provisioned TFTP server address, the phone will only complete half the upgrade and come up with an error message of “protocol application invalid.” This just means that the phone could not complete the second half of the upgrade and needs the TFTP IP address to be specified. Only problem is since there is no application running, there is no place to specify the address! Thank goodness for DHCP option 150 which does this for us when the phone grabs an IP address after loading the bootloader.en the phone grabs an IP address after loading the bootloader.

Below are instructions to upgrade/convert any Cisco 7940, 7941, 7942, 7945, 7960, 7961, 7962, 7965, 7970 and 7971 IP phones to any firmware you want from the Cisco web site (SIP/SCCP), and to recover any Cisco phone which may have screwed up somehow while upgrading firmware (like if you get the protocol application invalid message).

Step 1: Upgrading to SIP firmware 8-12-00
  1. Download SIP firmware 8.x from CCO Cisco Web site here.

    Note: You need to be a registered Cisco partner with a valid service contract otherwise you cannot download it directly from Cisco website, If you do not have a valid service contract you can click the link below:
    • Cisco 79xx firmware files download link 1
  2. Download the .zip file and extract it into your TFTP root directory. (See next step)
Step 2: Download and configure the DHCP/TFTP server
  1. TFTP/DHCP server under windows:
    1. Go here to download the TFTP/DHCP server – http://tftpd32.jounin.net/
      • Download and install version 3.23 <---YOU MUST DOWNLOAD AND INSTALL THIS VERSION!
    2. You will also have to configure your windows machine to use IP address of and subnet mask of
      • You'll configure this TFTP server to host the upgrade files via TFTP server. (There's an option to configure the working directory in the program to use for the stored firmware files on the windows machine – this must be set correctly!)
    3. Under DHCP server within the tftp32 program, enter the following and click SAVE.
      • IP pool starting address as
      • Size of pool as 250 (If your doing multiple phones, this just makes sure your phones are able to receive an IP address.)
      • Default router as
      • Mask as
      • Additional option, enter 150 in the first box, then 0x0101A8C0 in the second box (This number is in Hexadecimal format).
  2. TFTP/DHCP server under ubuntu:
    • First you need to install TFTP server:
      Code: Select all
      # sudo apt-get install tftpd-hpa
      Second you need to download DHCP server.
      Code: Select all
      # apt-get install dhcp3-server
      Thirdly, for option 150 you need to do the following changes in /etc/dhcp3/dhcpd.conf
      1. edit /etc/dhcp3/dhcpd.conf
      2. Copy the following section in the appropriate place

        option voip-tftp-server code 150 = ip-address; # DON’T change this
        option voip-tftp-server _PBX-IP_;

        default-lease-time 600;
        max-lease-time 7200;

        option subnet-mask;
        option broadcast-address;
        option routers;
        option domain-name-servers,;
        option domain-name “smartpbx.lan”;

        subnet netmask {
      3. restart tftp and dhcp server:
        Code: Select all
        # /etc/init.d/dhcp3-server restart
        # /etc/init.d/tftpd-hpa restart
Step 3: Configuration
  1. Download the file XMLDefault.cnf.xml from here and copy/paste it in to the TFTP boot folder (/var/lib/tftpboot)
    • make sure you write the correct firmware filename in <loadInformation>P0S3-8-12-00</loadInformation>
  2. Download SEP<MAC_Address>.cnf.xml from here and put it in firmware directory.
    • You must put the MAC address of each phone in the file (eg. SEP24B657B1DED4.cnf.xml). Note that for every phone you need one file with the MAC address of the phone.
  3. Download the file dialplan.xml from here and copy it into the firmware directory.

    Example dialplan.xml:
    Code: Select all
     <TEMPLATE MATCH="*" Timeout="5"/> <!-- Anything else -->
Step 4: Factory reset the phones and start configuration

Power Cycle the phone. Hold down the # key then power on the phone. When the light blinks on the phone line button, release the # key, then follow by pressing 123456789*0#. The firmware you put in the tftp root folder will start loading.

Once firmware upgrading finishes, verify the new SIP firmware version. Press “setting” then select:
  1. Device Configuration > SIP Configuration
  2. Model Information > Load File, Boot Load ID
  3. Status > Firmware Version


By Sponsor
By nabli.m
but tftp32 block in this step
Rcvd DHCP Discover Msg for IP, Mac 00:08:30:31:96:F8 [02/10 17:14:56.386]
Client requested address [02/10 17:14:56.386]
DHCP: proposed address [02/10 17:15:01.005]
Rcvd DHCP Rqst Msg for IP, Mac 00:08:30:31:96:F8 [02/10 17:15:01.005]
Previously allocated address acked [02/10 17:15:02.509]
Rcvd DHCP Rqst Msg for IP, Mac 00:08:30:31:96:F8 [02/10 17:17:31.466]
Previously allocated address acked [02/10 17:17:36.082]
Rcvd DHCP Rqst Msg for IP, Mac 00:08:30:31:96:F8 [02/10 17:20:06.354]
Previously allocated address acked [02/10 17:20:10.978]

Any idea!!

Just found out that the latest firmware build for …

Supported Products: OBi504vs OBi508vs Firm…

Supported Products: OBi200 OBi202 OBi300 OB…

These are unlocked and unbranded Snom 760 IP Phone…