Wireshark-users: Re: [Wireshark-users] TCP option
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Thu, 4 Oct 2007 15:07:00 -0700

On Oct 4, 2007, at 1:56 AM, Billie Chan wrote:

Any idea how come 12 bytes tcp.option occur?

Because the TCP implementation on the machine sending the TCP segment decided to add that option to the TCP segment.

What option is it? We'd need to know in order to try to guess why it's being added.