The direction is defined by a number of an autonomous system that sends or receives the traffic. The direction priority specified for autonomous system (if defined) overrides the priority specified by protocol. The direction priority specified for the traffic's source (if defined) overrides the priority specified for the destination.

One can change the IP list that belongs to an individual system and define an auxiliary individual system dynamically. It is described here: Configuring autonomous systems

The direction dependent priorities assigned by the system's administrator, are loaded by DPI from the file /etc/dpi/asnum.dscp

This file is created in two steps. First, the text file with a list of individual systems and their assigned priorities is created. Next, this file is converted into an internal format by a dedicated utility.

File format of autonomous systems' list and their priorities:

Each line of the file contains: AS_number <space> dscp_value. For example:

64512 cs0
64512 local
64513 drop
64514 pass
64514 peer

Here cs0 - is DSCP value.
The 'drop' keyword means that packets have not to be transmitted: they must be dropped.
The 'pass' keyword means that the traffic of this individual system must go through DPI with no analysis and processing.
The 'local' keyword means that the traffic of this system is treated as a local operator's one.
The 'peer' keyword means that the operator is in peering state with this system.
'local' and 'peer' do not effect the traffic's priority and are used for services. They are described there.

To convert this file into the internal format and to place it into the working directory for DPI usage:

cat my_as_dscp.txt|as2dscp /etc/dpi/asnum.dscp
service fastdpi reload

This configuration is loaded on the run, with no need to restart the service.