xs Active Applications Bit Mask

The Active Applications bit mask is representing every active application from the first 1024 'well defined' applications. Each application is represented by a single bit in the string. Application number 1 is represented by the first bit in the string. Bit value '1' means, the protocol is active. Bit value '0' means, the protocol is inactive. For example the FTP data application, assigned as number 20. If the FTP application is active, then the bit number 20 will be set to '1'.