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Is there anyway you could explain this theory or send a link? Much obliged .
On this forums, I and some other members (including forums owner KO) had discussed cyclic NAT problem. And KO agreed with my theory. I and KO had even discussed with “Wateen Engineers” but they (Wateen “Engineers”) totally reject the hypothesis and stand firm that their internet network is capable of handling all requests (connections). At that point we simply gave up and let it as it is.
If I recall correctly it was like 14 or 16 months ago, before forums was hacked. I even gave visual diagrams and other tracing data to proof my theory. And almost all agreed that Wateen’s circles of NAT is not good and will chock (it did many times) Wateen’s internal network.
You may try to find it’s remnants (if any left after hacking) in http://www.wiredpakistan.com/forums/viewtopic.php?id=11
Here is a brief description of my theory (you’ll need basic knowledge of computer networking and TCP/IP to understand it):
Wateen is using multiple layers of NAT in their internal network. A client (CPE device) is connected to Wateen’s internal network, instead of outside world of internet. In my finding there are at least 4 to 5 NAT layers between client’s CPE and internet. When a CPE make a request (connection) to open a port to any internet server (like port 80 that is commonly use for web) then client’s CPE send a request (open a random port to) to closet NAT server. That NAT server then make connection to next in outer circle. Eventually request reached out of Wateen’s internal network to internet where it start to jump from one ISP to another ISP. (Use tracer to see this in action).
The good thing is that the whole NAT transaction is transparent to user and software. However, there is a one big problem. There is a limitation in TCP/IP protocol that it can have maximum of 65535 port (theoretical limit) opened at one time.
Now just imagine, there are only 20,000 users (the actual figure is very high) of Wateen WiMAX. If each user open a web-page in their browser simultaneously, then each browser will open 4 connections (that’s the typical inbuilt limit of contemporary browsers).
20,000 x 4 = 80,000
However, due to limitation of 65,535 maximum ports, NAT server will grant or process only 65,535 connections while remaining 14,465 connection request will be lost (rejected in terms of network) by NAT server. That’s why we have to refresh a web-page many time to open it properly.
I guess my theory still stand true even today.
I hope that you get some idea about it.