====== Configuration ======
{{indexmenu_n>2}}

=====Configuring DSCP markup in IP/VLAN/MPLS headers=====
The option is configured or disabled by editing the configuration file **/etc/dpi/fastdpi.conf**.

<note warning>This is a cold parameter which requires restart of service!</note>
 
Enable prioritizing markup of a traffic on level:

<code>
set_packet_priority=1
</code>

  * 1 - IP header
  * 2 - VLAN/QinQ header
  * 3 - MPLS header


<note important>set_packet_priority=1 leads to patching of all packets that pass through DPI to set the priority in their headers. This operation takes a lot of resources. Therefore do not switch this flag on until you do not need to use these modified priorities on other network devices.</note>

Configuration parameters from [[en:dpi:dpi_options:opt_priority:priority_config|Assignment of priorities]] are sufficient for internal DPI usage.

===== Configuring DSCP Inheritance and Conversion =====
<note important>Not compatible with ''[[dpi:dpi_options:opt_priority:priority_settings#настройка_разметки_dscp_в_ip_vlan_mpls_заголовках|set_packet_priority]]'' — he's a priority..</note>
It is configured in the ''/etc/dpi/fastdpi.conf'' configuration file.
<code bash>
forward_packet_priority=<bitmask>
</code>
Bit masks:
  * Depending on the direction: 
    * 1 — conversion is applied to outbound traffic (subs->inet)
    * 2 — conversion is applied to outbound traffic (inet->subs)
  * Depending on the objects of conversion:
    * 4 — Conversion between VLAN and IP
    * 8 — IP to IP conversion

If no conversion file is specified (no ''/etc/dpi/dscpfrw.bin'' file), VLAN<->IP conversion is performed without conversion, i.e. the priority that was in the header (3 bits) is transferred to the other header (IP or VLAN) as it is.\\
If a conversion file is specified, a priority conversion is performed according to the rules specified in the file.

====Setting the priority conversion file====
<code bash>
vi test.txt
in cs0 cs1
in cs1 cs2
in cs2 keep
in default cs3
out default keep
out 0x1 0x2
out 0x2 0x3
out cs0 0x3F

cat test.txt|forw2dscp test.bin 
cp test.bin /etc/dpi/dscpfrw.bin
</code>