.NET Json Serialization, JSON_MaxJsonLengthExceeded when passing 2 Megabytes of data.

Question

What sets the JSON buffer length other than web.config or creating an instance of the JavaScriptSerializer?

Is anyone aware if ASP.Net, the .Net Framework, IIS, IE force or impose a buffer lenght forced at 2 Megabytes or data?

So far maxJsonLength is the only property I control.

All works as expected bellow 2Megabytes, but above that, it's JSON_MaxJsonLengthExceeded exception.