VOIP over VPN Tunnel

[Zayar Win]

Dear ,

          I would like to ask about VOIP Phone. I am using GRE VPN Tunnel between Head Office and Branches office. Currently I can ping the IP Addess of CUCM from Branches Office. And I had test  to Port 5060 by TCPING . It is open. In this case , Can I use VOIP Phone in Branches office?

Do I need to create Voice VLAN in Branches Office ? Please see the attached file for my scenario.

Thanks and Regards,

[Joel · Accepted solution]

You may wish to look at SRST - http://www.cisco.com/c/en/us/products/unified-communications/unified-survivable-remote-site-telephony/index.html

If SRST isn't an option, you can register the phones against your central call manager but they do need the ability to find it. Either pre-config the phones or rely on DHCP scope options. I've had to do this in the past, believe I created a voice VLAN as well.

Below from the manual.
Cisco IP Phones download their configuration from a TFTP server. When a Cisco IP Phone starts, if it does not have both the IP address and TFTP server IP address preconfigured, it sends a request with option 150 or 66 to the DHCP server to obtain this information.

DHCP option 150 provides the IP addresses of a list of TFTP servers.
DHCP option 66 gives the IP address or the hostname of a single TFTP server.

Joel

[Zayar Win]

Dear Joel,

            So , I have to use below config in Branches Router ?

=======================

   ip dhcp pool branch1
   network 192.168.100.0 255.255.255.0
   domain-name test.com
   option 150 ip 172.16.100.109 172.16.100.110 <<<=This ip address is CUCM ip it locate in DMZ
   dns-server 172.16.100.75
   default-router 192.168.100.1
   lease 3

========================

Thanks in Advance

[vasank]

Hi Zayar,

The above configuration looks fine to me.

Regards,

Vasanth

[Zayar Win]

Dear Mr. Joel,

           You are comment is very much helpful . Now I am compete project with your suggestion especially in option 150 -

Thanks you

Zayar

[vasank · Accepted solution]

Hi Zayar,

Phones should always be in voice vlan which allows easy discovery of DHCP scope without manually entering the admin vlan information on ip phone. as long as you have full mesh connectivity between branch and HQ and DMZ there wont be any issue.

Thanks,

Vasanth

[Zayar Win]

Dear Vasanth,

          Could you please show the DHCP config for Branches Router especially Phone can connect to CUCM from DMZ Head office ?

Thanks and Regards,

Zayar