Hello All,

I have a customer who wants a IP phone he can use from home. (a SMT-i520)I have a OfficeServ 7200s with a OAS card, I got the card and phones working in the office. I have looked through other threads in here and I can see what ports need to be opened in the firewall. I am hoping for a public IP from them, but I have not heard back yet.

Here are my questions:

If I get a public IP, do I have to tell the IT people to open those ports I mentioned above and thats it or is more need form them, also I think I tell them to poit to the IP address of the MP 20 right?

If I dont get a public IP all to myself, can I use another one just to point the remote IP phone to (example their email server IP which is public) would the IT guy have to forward those ports open ,a nd if he did to where, the OAS card of the MP-20 card, any answered would be appreciated.

You will need to forward some ports to the MP20S card, and some to the oas card.

If you have any ip trunks you will need to adjust some settings on your oas card when you setup the private with public (which ones depend on your software version).

You don't need a dedicated IP, just a static one (the mail server one will normally be static).

Do I still have to have the ports forwarded if I get a public Ip address? or you I just have to have them opened. I have the info on which ones the OAS uses, I guess the rest get forwarded to the MP20 address.

The manual I have is kind of confusing, it says I need 3 public Ip addresses one for the system one for the phone and one for the OAS card, is that true? Thanks for any replies, I am off to the GSBN to see if I can find any further info.

You can get by with (1) public IP and using port forwarding. Or you can use (2) public IPs and static assign them to the processor and OAS card.


Port forwarding depends on if the system will be behind a firewall. If so, then yes a port forward will be required or a 1-1 NAT. If not, then know your system will be completely public. This is not a good idea though. It will expose your system to attacks from the internet. If you do decide to go completely public, make sure that you are using version 4.60 software. It has some added security to help secure the system.

Ok, I got some info from the IT people, they have 2 public IP's to spare. I assign one to the MP20, and one to the OAS. I tell the IT people to port forward the OAS ports in the manaual to the OAS address, and the rest to the MP20 address. Hopefully I am right so far. Now when I program the phone, do I use the MP20 address as the server address? my next question is, how does the phone get a IP address from the system? They use DHCP in the office, can they do the same remotely? or will there have to be a public IP or a static IP assigned to the remote phone.

The phone can pull a DHCP address remotely. No special firewall requirements on the remote side as long as they are not blocking outgoing traffic. You will put the public IP address of the MP20 as the server address in the phone.