NAT Reverse

Hi there,

There has a private GPRS network. Each mobile vehicle unit has static
IPs communicate with Gateway Server Program exchange Messages, such as
GPS Position. Server use sessions like (session in telnet) to track
individual truck messages.

Here is come to a problem when there is no communications directly
exist between mobile vehicle and Gateway. I mean messages from mobile
vehicles are sent via internet (Using NAT). Gateway Server Program can
create only one session because all messages are coming from same
source IP address. Here is illustration
http://test.thipparath.com/GPRS/GPRS.jpg

Messages are in form of Packets over TCP protocol. I have already
tested TCP Relay/Socks Proxy/TCP Tunnel to forwards messages. But I can
only forwards data. Gateway Server Software sees Packets from source IP
address of Bounce Server.

On the other hand, I don't want to do TCP Spoofing/ SYN Flood since I
have no time and depth understanding of related knowledge. (Any one can
provide me links of Win32 IP spoof source code?)

Is there any way to do so? Or any idea would be appreciated.

Sincerely,
Jonathan

(*System is based on MS Platform.)

Re: NAT Reverse

yewinzaw@gmail.com wrote:

> Here is come to a problem when there is no communications directly
> exist between mobile vehicle and Gateway. I mean messages from mobile
> vehicles are sent via internet (Using NAT). Gateway Server Program can
> create only one session because all messages are coming from same
> source IP address.

But the sessions will have different port numbers.

-- Lassi

Re: NAT Reverse

On Sat, 25 Feb 2006 15:28:43 +0200, Lassi Hippeläinen
wrote:

>yewinzaw@gmail.com wrote:
>
>> Here is come to a problem when there is no communications directly
>> exist between mobile vehicle and Gateway. I mean messages from mobile
>> vehicles are sent via internet (Using NAT). Gateway Server Program can
>> create only one session because all messages are coming from same
>> source IP address.
>
>But the sessions will have different port numbers.
>
>-- Lassi

The Source will have different port numbers but the Destination will
be the same.

I think what you are looking for is a Firewall that can handle NAT T
I would think that you are sending this over a VPN?

What is happening is that your inbound connection from your Mobile
destination for your public NAT Firewall and it doesn't know how to
hand more then one NAT session at a time.

That is if I am understanding your drawing correctly.

Hope this helps