Common.StatisticType

As I mentioned above, the STATISTIC_SERVER_SIDE_BYTES_IN/OUT are the bytes that have gone in and out of the internal network. The ASM module on BIG-IP is still internal to the box so the server side stats aren't necessarily the same as those in/out of AS if you have that module enabled.

Here's a diagram to help out things in perspective

        (bytes_in)   (server_side_bytes_out) 
            ->                ->
Browser(ext)       BIG-IP             Server(int)
            <-                <-
        (bytes_out)  (server_side_bytes_in)

the numbers for server_side and external bytes in/out can be different if you have BIG-IP modify any of the content.

So, the answer is no that you should not sum up the bytes_in/out with the server_side_bytes_in/out or you will effectively double the total number of bytes. I would recommend summing the STATISTIC_BYTES_IN and STATISTIC_BYTES_OUT on the external interface to give an effective total bytes in/out.

-Joe