Policing of the Common Channel [Документация VAS Experts]
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    en:dpi:dpi_options:opt_shaping:shaping_settings [2020/02/05 17:31] – ↷ Page moved from en:dpi:dpi_options:base_functionality:opt_shaping:shaping_settings to en:dpi:dpi_options:opt_shaping:shaping_settings lexx26en:dpi:dpi_options:opt_shaping:shaping_settings [2025/08/19 15:41] (current) – elena.krasnobryzh
    Line 1: Line 1:
    -====== Configuration ======+====== Policing of the Common Channel ====== 
     +{{indexmenu_n>2}} 
     +The option is configured or disabled by parameters in configuration file **/etc/dpi/fastdpi.conf.**
      
     +<note>To apply the settings, you must perform a service reload: **service fastdpi reload**</note>
     +
     +<note warning>Using common channel policing entails additional internal locks, which reduces system performance to 40G (when using tbf) and to 20G (when using htb) of total traffic on the common channel, regardless of the number of cores.</note>
     +
     +The bandwidth limits are set up by each of 8 protocol classes (groups) available. 
     +
     +When using **TBF (Token Bucket Function)**, a specific rate is set for each class of traffic:
     +<code>
     +#For the inbound traffic
     +tbf_inbound_class0=rate 15mbit
     +tbf_inbound_class1=rate 15mbit
     +tbf_inbound_class2=rate 15mbit
     +tbf_inbound_class3=rate 15mbit
     +tbf_inbound_class4=rate 15mbit
     +tbf_inbound_class5=rate 15mbit
     +tbf_inbound_class6=rate 15mbit
     +tbf_inbound_class7=rate 15mbit
     +#For the outbound traffic
     +tbf_class0=rate 15mbit
     +tbf_class1=rate 15mbit
     +tbf_class2=rate 15mbit
     +tbf_class3=rate 15mbit
     +tbf_class4=rate 15mbit
     +tbf_class5=rate 15mbit
     +tbf_class6=rate 15mbit
     +tbf_class7=rate 15mbit
     +</code>
     +One can optionally indicate parameters peakrate, burst, cburst. The bandwidth is not limited for a class with no explicit restrictions.
     +
     +When **HTB (Hierarchical Token Bucket)** is used, the overall and borrowed class rates are specified:
     +<code>
     +#For the inbound traffic
     +htb_inbound_root=rate 900mbit 
     +htb_inbound_class0=rate 300mbit ceil 900mbit
     +htb_inbound_class1=rate 100mbit ceil 200mbit
     +htb_inbound_class2=rate 100mbit ceil 200mbit
     +htb_inbound_class3=rate 100mbit ceil 200mbit
     +htb_inbound_class4=rate 100mbit ceil 100mbit
     +htb_inbound_class5=rate 100mbit ceil 100mbit
     +htb_inbound_class6=rate 50mbit  ceil 100mbit
     +htb_inbound_class7=rate 50mbit  ceil 100mbit
     +#For the outbound traffic
     +htb_root=rate 900mbit 
     +htb_class0=rate 300mbit ceil 900mbit
     +htb_class1=rate 100mbit ceil 200mbit
     +htb_class2=rate 100mbit ceil 200mbit
     +htb_class3=rate 100mbit ceil 200mbit
     +htb_class4=rate 100mbit ceil 100mbit
     +htb_class5=rate 100mbit ceil 100mbit
     +htb_class6=rate 50mbit  ceil 100mbit
     +htb_class7=rate 50mbit  ceil 100mbit
     +</code>
     +Here:\\
     +htb_root - is a root class that specifies the total bandwidth. The bandwidth redistribution is arranged within this class. The usage can grow up till this limit, if no ceil is specified
     +rate - minimal bandwidth
     +ceil - maximal bandwidth that can be borrowed from the root class if available
     +One can optionally specify parameters burst, cburst. The sum of parameters rate of all classes must not exceed the overall bandwidth limit. Otherwise the behaviour is undefined.
     +
     +Bandwidth allocation for some classes (for example, peering) can be deduced from the HTB if you specify the keyword "static: for them in the description, in this case the restriction for this class will work like tbf without binding to htb_root
     +<code>
     +htb_inbound_class6 = rate 200mbit static
     +htb_class6 = rate 200mbit static
     +</code>
     +
     +//The advanced users// can activate the feedback loop method. It works as follows:
     +
     +The inbound traffic limit is set up in the configuration. The ceil parameter is specified for class htb_root:
     +<code>
     +htb_inbound_root=rate 800mbit ceil 950mbit
     +htb_root=rate 450mbit ceil 600mbit
     +</code>
     +
     +On exceeding of the specified rate=800mbit by the inbound traffic, the upper limit ceil for the outbound traffic starts to decrease. The latest limit is specified by the parameter htb_root ceil=600mbit. However, even when the inbound traffic exceeds ceil=950mbit, the outbound traffic would not be restricted stronger than specified by htb_root rate=450mbit. The percentage of excess traffic is counted by the range ceil 950mbit <-> rate 800mbit. The outbound traffic is reduced by the same percentage. On the reduction of сeil value specified in htb_root, other classes redistribute the traffic to keep the total limit set up in htb_root.
     +
     +This method is effective for protocols operating by query - reply scheme. Limitations of the outbound traffic (query) lead to decrease in the inbound one (reply). Most of application protocols belong to this class.
     +
     +==Notes:== 
     +If the limit is not specified for some class, it can take all the bandwidth available.\\
     +The correspondence between dscp priority and poliсing class depends on the [[en:dpi:dpi_options:opt_priority:dscp_table|setting class_order]]