--- doc/tex/qos.tex 2008-12-09 17:00:46.000000000 -0800 +++ doc/tex/qos.tex.ksh 2008-12-09 17:01:18.000000000 -0800 @@ -1,23 +1,23 @@ \subsubsection{Introduction} -Asterisk support different QoS settings on application level on various protocol -on any of signaling and media. Type of Service (TOS) byte can be set on -outgoing IP packets for various protocols. The TOS byte is used by the network -to provide some level of Quality of Service (QoS) even if the network is -congested with other traffic. - -Also asterisk running on Linux can set 802.1p CoS marks in VLAN packets for all -used VoIP protocols. It is useful when you are working in switched environment. -In fact asterisk only set priority for Linux socket. For mapping this priority +Asterisk supports different QoS settings at the application level for various +protocols on both signaling and media. The Type of Service (TOS) byte can be +set on outgoing IP packets for various protocols. The TOS byte is used by the +network to provide some level of Quality of Service (QoS) even if the network +is congested with other traffic. + +Asterisk running on Linux can also set 802.1p CoS marks in VLAN packets for the +VoIP protocols it uses. This is useful when working in a switched environment. +In fact Asterisk only set priority for Linux socket. For mapping this priority and VLAN CoS mark you need to use this command: \begin{verbatim} vconfig set_egress_map [vlan-device] [skb-priority] [vlan-qos] \end{verbatim} -In table behind shown all voice channels and other modules of asterisk, that -support QoS settings for network traffic and type of traffic which can have -QoS settings. +The table below shows all VoIP channel drivers and other Asterisk modules that +support QoS settings for network traffic. It also shows the type(s) of +traffic for which each module can support setting QoS settings. \begin{verbatim} Channel Drivers @@ -53,19 +53,19 @@ The tos* parameters also take numeric values. -Note, that on Linux system you can use ef value in case your asterisk is running -from a user other then root only when you have compiled asterisk with libcap. +Note that on a Linux system, Asterisk must be compiled with libcap in order to +use the ef tos setting if Asterisk is not run as root. The lowdelay, throughput, reliability, mincost, and none values are removed in current releases. \subsubsection{802.1p CoS values} -As far as 802.1p uses 3 bites from VLAN header, there are parameter can take -integer values from 0 to 7. +Because 802.1p uses 3 bits of the VLAN header, this parameter can take integer +values from 0 to 7. \subsubsection{Recommended values} -Recommended values shown above and also included in sample configuration files: +The recommended values shown below are also included in sample configuration files: \begin{verbatim} +============+=========+======+ | | tos | cos | @@ -93,20 +93,21 @@ \subsubsection{SIP} -In sip.conf, there are three parameters that control the TOS settings: +In sip.conf, there are four parameters that control the TOS settings: "tos\_sip", "tos\_audio", "tos\_video" and "tos\_text". tos\_sip controls what TOS SIP call signaling packets are set to. tos\_audio, tos\_video -and tos\_text controls what TOS RTP audio, video or text accordingly +and tos\_text control what TOS RTP audio, video or text accordingly packets are set to. There are four parameters to control 802.1p CoS: "cos\_sip", "cos\_audio", -"cos\_video" and "cos\_text". It behavior the same as written above. +"cos\_video" and "cos\_text". The behavior of these parameters is the +same as for the SIP TOS settings, described above. \subsubsection{Other RTP channels} chan\_mgcp, chan\_h323, chan\_skinny and chan\_unistim also support TOS and -CoS via setting tos and cos parameters in correspond to module config -files. Naming style and behavior same as for chan\_sip. +CoS via setting tos and cos parameters in their corresponding configuration +files. Naming style and behavior are the same as for chan\_sip. \subsubsection{Reference}