Message ID | 1463385100-11369-1-git-send-email-bala.manoharan@linaro.org |
---|---|
State | Accepted |
Commit | c47434431936bb176f7937f1afc227732757d5fe |
Headers | show |
FYI @Bill: Looks like you did a reply instead of reply-all :) Regards, Bala ---------- Forwarded message ---------- From: Bill Fischofer <bill.fischofer@linaro.org> Date: 16 May 2016 at 20:20 Subject: Re: [PATCHv2] doc: users-guide: add packet marking documentation To: Balasubramanian Manoharan <bala.manoharan@linaro.org> On Mon, May 16, 2016 at 2:51 AM, Balasubramanian Manoharan <bala.manoharan@linaro.org> wrote: > > Updates packet marking api documentation to traffic manager user guide > > Signed-off-by: Balasubramanian Manoharan <bala.manoharan@linaro.org> Reviewed-and-tested-by: Bill Fischofer <bill.fischofer@linaro.org> > > --- > v2: document format update > doc/users-guide/users-guide-tm.adoc | 73 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) > > diff --git a/doc/users-guide/users-guide-tm.adoc b/doc/users-guide/users-guide-tm.adoc > index 12685b2..e02697b 100644 > --- a/doc/users-guide/users-guide-tm.adoc > +++ b/doc/users-guide/users-guide-tm.adoc > @@ -263,6 +263,79 @@ settings for any TM system, though in most cases a TM system can (and should) > be created/instantiated with smaller values, since lower values will often > result in faster operation and/or less memory used. > > +==== Packet Marking > + > +The Packet Marking API is used to mark the packet based upon the final packet > +color assigned to it when it reaches the egress node. > +This is an optional feature and if available on the platform is used to reflect > +the packet color on IPv4/IPv6 DiffServ filed in accordance with https://www.ietf.org/rfc/rfc2474.txt[RFC 2474]. > +There are three different packet marking fields supported they are, > +1). Assured forwarding in accordance with https://www.ietf.org/rfc/rfc2597.txt[RFC 2597], the DSCP is marked to > +set the packet Drop precedence in accordance with the color, i.e High Drop > +precedence for RED, Medium Drop precedence for YELLOW and leave the DSCP > +unchanged if the color is GREEN. > +2). Explicit Congestion Notification protocol per https://www.ietf.org/rfc/rfc3168.txt[RFC 3168], where a router > +encountering congestion can notify it by setting the lower 2 bits in > +DiffServ field to "11" Congestion Encountered code, which will ultimately > +reduce the transmission rate of the packet sender. > +3). In IEEE 802.1q VLAN tag header contains a DE - Drop Eligibility bit for > +marking a packet for Downstream switches, and is valid for Ethernet packet > +containing a VLAN tag. > + > +RFC 3168 is only valid for TCP packets whereas RFC 2597 is valid for IPv4/IPv6 > +traffic. > + > +The values are set per color and hence the implementation may support these > +parameters only for a specific colors. marking_colors_supported field in > +capabilities structure can be used to check which colors are supported for > +marking. > + > +==== Vlan Marking. > + > +This vlan marking is used to enable the drop eligibility on the packet > +based on the packet color. If drop eligibility is enabled then the > +implementation will set the one bit VLAN Drop Eligibility Indicator (DEI) > +field (but only for packets that already carry a VLAN tag) of a packet based > +upon the final packet color assigned to the packet when it reaches the egress > +node. When drop_eligible_enabled is false, then the given color has > +no effect on the VLAN fields. See IEEE 802.1q for more details. > +`vlan_marking_supported` boolean in capability structure indicates whether this > +feature is supported by the implementation. > + > +==== Explicit Congestion Notification Marking. > + > +The `odp_tm_ecn_marking()` function allows one to configure the TM > +egress so that the two bit ECN subfield of the eight bit TOS field of an > +IPv4 packet OR the eight bit Traffic Class (TC) field of an IPv6 packet can be > +selectively modified based upon the final color assigned to the packet when it > +reaches the egress. Note that the IPv4 header checksum will be updated - > +but only if the IPv4 TOS field actually changes as a result of this > +setting or the `odp_tm_drop_prec_marking()` setting. For IPv6, since there is > +no header checksum, nothing needs to be done. If ECN is enabled for a > +particular color then ECN subfield will be set to _ECN_CE_ _i.e.,_ congestion > +experienced. > +`ecn_marking_supported` boolean in capability structure indicates whether this > +feature is supported by the implementation. > + > +==== Drop Precedence Marking. > + > +The Drop precedence marking allows one to configure the TM > +egress to support Assured forwarding in accordance with https://www.ietf.org/rfc/rfc2597.txt[RFC 2597]. > +The Drop Precedence bits are contained within the six bit Differentiated > +Services Code Point subfield of the IPv4 TOS field or the IPv6 Traffic > +Class (TC) field. Specifically the Drop Precedence sub-subfield can be > +accessed with a DSCP bit mask of 0x06. When enabled for a given color, > +these two bits will be set to Medium Drop Precedence (value 0x4) if the > +color is ODP_PACKET_YELLOW, set to High Drop Precedence (value 0x6) if > +the color is ODP_PACKET_RED. > + > +Note that the IPv4 header checksum will be updated - but only if the > +IPv4 TOS field actually changes as a result of this setting or the > +`odp_tm_ecn_marking()` setting. For IPv6, since there is no header checksum, > +nothing else needs to be done. > +`drop_prec_marking_supported` boolean in capability structure indicates whether > +this feature is supported by the implementation. > + > === Examples > > .Create a tm_node chain for two nodes and associate the scheduler > -- > 1.9.1 >
On Monday, May 16, 2016, Balasubramanian Manoharan < bala.manoharan@linaro.org> wrote: > Updates packet marking api documentation to traffic manager user guide > > Signed-off-by: Balasubramanian Manoharan <bala.manoharan@linaro.org > <javascript:;>> Reviewed-and-tested-by: Bill Fischofer <bill.fischofer@linaro.org> > --- > v2: document format update > doc/users-guide/users-guide-tm.adoc | 73 > +++++++++++++++++++++++++++++++++++++ > 1 file changed, 73 insertions(+) > > diff --git a/doc/users-guide/users-guide-tm.adoc > b/doc/users-guide/users-guide-tm.adoc > index 12685b2..e02697b 100644 > --- a/doc/users-guide/users-guide-tm.adoc > +++ b/doc/users-guide/users-guide-tm.adoc > @@ -263,6 +263,79 @@ settings for any TM system, though in most cases a TM > system can (and should) > be created/instantiated with smaller values, since lower values will often > result in faster operation and/or less memory used. > > +==== Packet Marking > + > +The Packet Marking API is used to mark the packet based upon the final > packet > +color assigned to it when it reaches the egress node. > +This is an optional feature and if available on the platform is used to > reflect > +the packet color on IPv4/IPv6 DiffServ filed in accordance with > https://www.ietf.org/rfc/rfc2474.txt[RFC 2474]. > +There are three different packet marking fields supported they are, > +1). Assured forwarding in accordance with > https://www.ietf.org/rfc/rfc2597.txt[RFC 2597], the DSCP is marked to > +set the packet Drop precedence in accordance with the color, i.e High Drop > +precedence for RED, Medium Drop precedence for YELLOW and leave the DSCP > +unchanged if the color is GREEN. > +2). Explicit Congestion Notification protocol per > https://www.ietf.org/rfc/rfc3168.txt[RFC 3168], where a router > +encountering congestion can notify it by setting the lower 2 bits in > +DiffServ field to "11" Congestion Encountered code, which will ultimately > +reduce the transmission rate of the packet sender. > +3). In IEEE 802.1q VLAN tag header contains a DE - Drop Eligibility bit > for > +marking a packet for Downstream switches, and is valid for Ethernet packet > +containing a VLAN tag. > + > +RFC 3168 is only valid for TCP packets whereas RFC 2597 is valid for > IPv4/IPv6 > +traffic. > + > +The values are set per color and hence the implementation may support > these > +parameters only for a specific colors. marking_colors_supported field in > +capabilities structure can be used to check which colors are supported for > +marking. > + > +==== Vlan Marking. > + > +This vlan marking is used to enable the drop eligibility on the packet > +based on the packet color. If drop eligibility is enabled then the > +implementation will set the one bit VLAN Drop Eligibility Indicator (DEI) > +field (but only for packets that already carry a VLAN tag) of a packet > based > +upon the final packet color assigned to the packet when it reaches the > egress > +node. When drop_eligible_enabled is false, then the given color has > +no effect on the VLAN fields. See IEEE 802.1q for more details. > +`vlan_marking_supported` boolean in capability structure indicates > whether this > +feature is supported by the implementation. > + > +==== Explicit Congestion Notification Marking. > + > +The `odp_tm_ecn_marking()` function allows one to configure the TM > +egress so that the two bit ECN subfield of the eight bit TOS field of an > +IPv4 packet OR the eight bit Traffic Class (TC) field of an IPv6 packet > can be > +selectively modified based upon the final color assigned to the packet > when it > +reaches the egress. Note that the IPv4 header checksum will be updated - > +but only if the IPv4 TOS field actually changes as a result of this > +setting or the `odp_tm_drop_prec_marking()` setting. For IPv6, since > there is > +no header checksum, nothing needs to be done. If ECN is enabled for a > +particular color then ECN subfield will be set to _ECN_CE_ _i.e.,_ > congestion > +experienced. > +`ecn_marking_supported` boolean in capability structure indicates whether > this > +feature is supported by the implementation. > + > +==== Drop Precedence Marking. > + > +The Drop precedence marking allows one to configure the TM > +egress to support Assured forwarding in accordance with > https://www.ietf.org/rfc/rfc2597.txt[RFC 2597]. > +The Drop Precedence bits are contained within the six bit Differentiated > +Services Code Point subfield of the IPv4 TOS field or the IPv6 Traffic > +Class (TC) field. Specifically the Drop Precedence sub-subfield can be > +accessed with a DSCP bit mask of 0x06. When enabled for a given color, > +these two bits will be set to Medium Drop Precedence (value 0x4) if the > +color is ODP_PACKET_YELLOW, set to High Drop Precedence (value 0x6) if > +the color is ODP_PACKET_RED. > + > +Note that the IPv4 header checksum will be updated - but only if the > +IPv4 TOS field actually changes as a result of this setting or the > +`odp_tm_ecn_marking()` setting. For IPv6, since there is no header > checksum, > +nothing else needs to be done. > +`drop_prec_marking_supported` boolean in capability structure indicates > whether > +this feature is supported by the implementation. > + > === Examples > > .Create a tm_node chain for two nodes and associate the scheduler > -- > 1.9.1 > >
Sorry about that. Fixed. On Monday, May 16, 2016, Bala Manoharan <bala.manoharan@linaro.org> wrote: > FYI > > @Bill: Looks like you did a reply instead of reply-all :) > > Regards, > Bala > > ---------- Forwarded message ---------- > From: Bill Fischofer <bill.fischofer@linaro.org <javascript:;>> > Date: 16 May 2016 at 20:20 > Subject: Re: [PATCHv2] doc: users-guide: add packet marking documentation > To: Balasubramanian Manoharan <bala.manoharan@linaro.org <javascript:;>> > > > > > On Mon, May 16, 2016 at 2:51 AM, Balasubramanian Manoharan > <bala.manoharan@linaro.org <javascript:;>> wrote: > > > > Updates packet marking api documentation to traffic manager user guide > > > > Signed-off-by: Balasubramanian Manoharan <bala.manoharan@linaro.org > <javascript:;>> > > > Reviewed-and-tested-by: Bill Fischofer <bill.fischofer@linaro.org > <javascript:;>> > > > > > --- > > v2: document format update > > doc/users-guide/users-guide-tm.adoc | 73 > +++++++++++++++++++++++++++++++++++++ > > 1 file changed, 73 insertions(+) > > > > diff --git a/doc/users-guide/users-guide-tm.adoc > b/doc/users-guide/users-guide-tm.adoc > > index 12685b2..e02697b 100644 > > --- a/doc/users-guide/users-guide-tm.adoc > > +++ b/doc/users-guide/users-guide-tm.adoc > > @@ -263,6 +263,79 @@ settings for any TM system, though in most cases a > TM system can (and should) > > be created/instantiated with smaller values, since lower values will > often > > result in faster operation and/or less memory used. > > > > +==== Packet Marking > > + > > +The Packet Marking API is used to mark the packet based upon the final > packet > > +color assigned to it when it reaches the egress node. > > +This is an optional feature and if available on the platform is used to > reflect > > +the packet color on IPv4/IPv6 DiffServ filed in accordance with > https://www.ietf.org/rfc/rfc2474.txt[RFC 2474]. > > +There are three different packet marking fields supported they are, > > +1). Assured forwarding in accordance with > https://www.ietf.org/rfc/rfc2597.txt[RFC 2597], the DSCP is marked to > > +set the packet Drop precedence in accordance with the color, i.e High > Drop > > +precedence for RED, Medium Drop precedence for YELLOW and leave the DSCP > > +unchanged if the color is GREEN. > > +2). Explicit Congestion Notification protocol per > https://www.ietf.org/rfc/rfc3168.txt[RFC 3168], where a router > > +encountering congestion can notify it by setting the lower 2 bits in > > +DiffServ field to "11" Congestion Encountered code, which will > ultimately > > +reduce the transmission rate of the packet sender. > > +3). In IEEE 802.1q VLAN tag header contains a DE - Drop Eligibility bit > for > > +marking a packet for Downstream switches, and is valid for Ethernet > packet > > +containing a VLAN tag. > > + > > +RFC 3168 is only valid for TCP packets whereas RFC 2597 is valid for > IPv4/IPv6 > > +traffic. > > + > > +The values are set per color and hence the implementation may support > these > > +parameters only for a specific colors. marking_colors_supported field in > > +capabilities structure can be used to check which colors are supported > for > > +marking. > > + > > +==== Vlan Marking. > > + > > +This vlan marking is used to enable the drop eligibility on the packet > > +based on the packet color. If drop eligibility is enabled then the > > +implementation will set the one bit VLAN Drop Eligibility Indicator > (DEI) > > +field (but only for packets that already carry a VLAN tag) of a packet > based > > +upon the final packet color assigned to the packet when it reaches the > egress > > +node. When drop_eligible_enabled is false, then the given color has > > +no effect on the VLAN fields. See IEEE 802.1q for more details. > > +`vlan_marking_supported` boolean in capability structure indicates > whether this > > +feature is supported by the implementation. > > + > > +==== Explicit Congestion Notification Marking. > > + > > +The `odp_tm_ecn_marking()` function allows one to configure the TM > > +egress so that the two bit ECN subfield of the eight bit TOS field of an > > +IPv4 packet OR the eight bit Traffic Class (TC) field of an IPv6 packet > can be > > +selectively modified based upon the final color assigned to the packet > when it > > +reaches the egress. Note that the IPv4 header checksum will be updated > - > > +but only if the IPv4 TOS field actually changes as a result of this > > +setting or the `odp_tm_drop_prec_marking()` setting. For IPv6, since > there is > > +no header checksum, nothing needs to be done. If ECN is enabled for a > > +particular color then ECN subfield will be set to _ECN_CE_ _i.e.,_ > congestion > > +experienced. > > +`ecn_marking_supported` boolean in capability structure indicates > whether this > > +feature is supported by the implementation. > > + > > +==== Drop Precedence Marking. > > + > > +The Drop precedence marking allows one to configure the TM > > +egress to support Assured forwarding in accordance with > https://www.ietf.org/rfc/rfc2597.txt[RFC 2597]. > > +The Drop Precedence bits are contained within the six bit Differentiated > > +Services Code Point subfield of the IPv4 TOS field or the IPv6 Traffic > > +Class (TC) field. Specifically the Drop Precedence sub-subfield can be > > +accessed with a DSCP bit mask of 0x06. When enabled for a given color, > > +these two bits will be set to Medium Drop Precedence (value 0x4) if the > > +color is ODP_PACKET_YELLOW, set to High Drop Precedence (value 0x6) if > > +the color is ODP_PACKET_RED. > > + > > +Note that the IPv4 header checksum will be updated - but only if the > > +IPv4 TOS field actually changes as a result of this setting or the > > +`odp_tm_ecn_marking()` setting. For IPv6, since there is no header > checksum, > > +nothing else needs to be done. > > +`drop_prec_marking_supported` boolean in capability structure indicates > whether > > +this feature is supported by the implementation. > > + > > === Examples > > > > .Create a tm_node chain for two nodes and associate the scheduler > > -- > > 1.9.1 > > >
Merged, Maxim. On 05/17/16 05:40, Bill Fischofer wrote: > On Monday, May 16, 2016, Balasubramanian Manoharan < > bala.manoharan@linaro.org> wrote: > >> Updates packet marking api documentation to traffic manager user guide >> >> Signed-off-by: Balasubramanian Manoharan <bala.manoharan@linaro.org >> <javascript:;>> > > Reviewed-and-tested-by: Bill Fischofer <bill.fischofer@linaro.org> > >> --- >> v2: document format update >> doc/users-guide/users-guide-tm.adoc | 73 >> +++++++++++++++++++++++++++++++++++++ >> 1 file changed, 73 insertions(+) >> >> diff --git a/doc/users-guide/users-guide-tm.adoc >> b/doc/users-guide/users-guide-tm.adoc >> index 12685b2..e02697b 100644 >> --- a/doc/users-guide/users-guide-tm.adoc >> +++ b/doc/users-guide/users-guide-tm.adoc >> @@ -263,6 +263,79 @@ settings for any TM system, though in most cases a TM >> system can (and should) >> be created/instantiated with smaller values, since lower values will often >> result in faster operation and/or less memory used. >> >> +==== Packet Marking >> + >> +The Packet Marking API is used to mark the packet based upon the final >> packet >> +color assigned to it when it reaches the egress node. >> +This is an optional feature and if available on the platform is used to >> reflect >> +the packet color on IPv4/IPv6 DiffServ filed in accordance with >> https://www.ietf.org/rfc/rfc2474.txt[RFC 2474]. >> +There are three different packet marking fields supported they are, >> +1). Assured forwarding in accordance with >> https://www.ietf.org/rfc/rfc2597.txt[RFC 2597], the DSCP is marked to >> +set the packet Drop precedence in accordance with the color, i.e High Drop >> +precedence for RED, Medium Drop precedence for YELLOW and leave the DSCP >> +unchanged if the color is GREEN. >> +2). Explicit Congestion Notification protocol per >> https://www.ietf.org/rfc/rfc3168.txt[RFC 3168], where a router >> +encountering congestion can notify it by setting the lower 2 bits in >> +DiffServ field to "11" Congestion Encountered code, which will ultimately >> +reduce the transmission rate of the packet sender. >> +3). In IEEE 802.1q VLAN tag header contains a DE - Drop Eligibility bit >> for >> +marking a packet for Downstream switches, and is valid for Ethernet packet >> +containing a VLAN tag. >> + >> +RFC 3168 is only valid for TCP packets whereas RFC 2597 is valid for >> IPv4/IPv6 >> +traffic. >> + >> +The values are set per color and hence the implementation may support >> these >> +parameters only for a specific colors. marking_colors_supported field in >> +capabilities structure can be used to check which colors are supported for >> +marking. >> + >> +==== Vlan Marking. >> + >> +This vlan marking is used to enable the drop eligibility on the packet >> +based on the packet color. If drop eligibility is enabled then the >> +implementation will set the one bit VLAN Drop Eligibility Indicator (DEI) >> +field (but only for packets that already carry a VLAN tag) of a packet >> based >> +upon the final packet color assigned to the packet when it reaches the >> egress >> +node. When drop_eligible_enabled is false, then the given color has >> +no effect on the VLAN fields. See IEEE 802.1q for more details. >> +`vlan_marking_supported` boolean in capability structure indicates >> whether this >> +feature is supported by the implementation. >> + >> +==== Explicit Congestion Notification Marking. >> + >> +The `odp_tm_ecn_marking()` function allows one to configure the TM >> +egress so that the two bit ECN subfield of the eight bit TOS field of an >> +IPv4 packet OR the eight bit Traffic Class (TC) field of an IPv6 packet >> can be >> +selectively modified based upon the final color assigned to the packet >> when it >> +reaches the egress. Note that the IPv4 header checksum will be updated - >> +but only if the IPv4 TOS field actually changes as a result of this >> +setting or the `odp_tm_drop_prec_marking()` setting. For IPv6, since >> there is >> +no header checksum, nothing needs to be done. If ECN is enabled for a >> +particular color then ECN subfield will be set to _ECN_CE_ _i.e.,_ >> congestion >> +experienced. >> +`ecn_marking_supported` boolean in capability structure indicates whether >> this >> +feature is supported by the implementation. >> + >> +==== Drop Precedence Marking. >> + >> +The Drop precedence marking allows one to configure the TM >> +egress to support Assured forwarding in accordance with >> https://www.ietf.org/rfc/rfc2597.txt[RFC 2597]. >> +The Drop Precedence bits are contained within the six bit Differentiated >> +Services Code Point subfield of the IPv4 TOS field or the IPv6 Traffic >> +Class (TC) field. Specifically the Drop Precedence sub-subfield can be >> +accessed with a DSCP bit mask of 0x06. When enabled for a given color, >> +these two bits will be set to Medium Drop Precedence (value 0x4) if the >> +color is ODP_PACKET_YELLOW, set to High Drop Precedence (value 0x6) if >> +the color is ODP_PACKET_RED. >> + >> +Note that the IPv4 header checksum will be updated - but only if the >> +IPv4 TOS field actually changes as a result of this setting or the >> +`odp_tm_ecn_marking()` setting. For IPv6, since there is no header >> checksum, >> +nothing else needs to be done. >> +`drop_prec_marking_supported` boolean in capability structure indicates >> whether >> +this feature is supported by the implementation. >> + >> === Examples >> >> .Create a tm_node chain for two nodes and associate the scheduler >> -- >> 1.9.1 >> >> > _______________________________________________ > lng-odp mailing list > lng-odp@lists.linaro.org > https://lists.linaro.org/mailman/listinfo/lng-odp
diff --git a/doc/users-guide/users-guide-tm.adoc b/doc/users-guide/users-guide-tm.adoc index 12685b2..e02697b 100644 --- a/doc/users-guide/users-guide-tm.adoc +++ b/doc/users-guide/users-guide-tm.adoc @@ -263,6 +263,79 @@ settings for any TM system, though in most cases a TM system can (and should) be created/instantiated with smaller values, since lower values will often result in faster operation and/or less memory used. +==== Packet Marking + +The Packet Marking API is used to mark the packet based upon the final packet +color assigned to it when it reaches the egress node. +This is an optional feature and if available on the platform is used to reflect +the packet color on IPv4/IPv6 DiffServ filed in accordance with https://www.ietf.org/rfc/rfc2474.txt[RFC 2474]. +There are three different packet marking fields supported they are, +1). Assured forwarding in accordance with https://www.ietf.org/rfc/rfc2597.txt[RFC 2597], the DSCP is marked to +set the packet Drop precedence in accordance with the color, i.e High Drop +precedence for RED, Medium Drop precedence for YELLOW and leave the DSCP +unchanged if the color is GREEN. +2). Explicit Congestion Notification protocol per https://www.ietf.org/rfc/rfc3168.txt[RFC 3168], where a router +encountering congestion can notify it by setting the lower 2 bits in +DiffServ field to "11" Congestion Encountered code, which will ultimately +reduce the transmission rate of the packet sender. +3). In IEEE 802.1q VLAN tag header contains a DE - Drop Eligibility bit for +marking a packet for Downstream switches, and is valid for Ethernet packet +containing a VLAN tag. + +RFC 3168 is only valid for TCP packets whereas RFC 2597 is valid for IPv4/IPv6 +traffic. + +The values are set per color and hence the implementation may support these +parameters only for a specific colors. marking_colors_supported field in +capabilities structure can be used to check which colors are supported for +marking. + +==== Vlan Marking. + +This vlan marking is used to enable the drop eligibility on the packet +based on the packet color. If drop eligibility is enabled then the +implementation will set the one bit VLAN Drop Eligibility Indicator (DEI) +field (but only for packets that already carry a VLAN tag) of a packet based +upon the final packet color assigned to the packet when it reaches the egress +node. When drop_eligible_enabled is false, then the given color has +no effect on the VLAN fields. See IEEE 802.1q for more details. +`vlan_marking_supported` boolean in capability structure indicates whether this +feature is supported by the implementation. + +==== Explicit Congestion Notification Marking. + +The `odp_tm_ecn_marking()` function allows one to configure the TM +egress so that the two bit ECN subfield of the eight bit TOS field of an +IPv4 packet OR the eight bit Traffic Class (TC) field of an IPv6 packet can be +selectively modified based upon the final color assigned to the packet when it +reaches the egress. Note that the IPv4 header checksum will be updated - +but only if the IPv4 TOS field actually changes as a result of this +setting or the `odp_tm_drop_prec_marking()` setting. For IPv6, since there is +no header checksum, nothing needs to be done. If ECN is enabled for a +particular color then ECN subfield will be set to _ECN_CE_ _i.e.,_ congestion +experienced. +`ecn_marking_supported` boolean in capability structure indicates whether this +feature is supported by the implementation. + +==== Drop Precedence Marking. + +The Drop precedence marking allows one to configure the TM +egress to support Assured forwarding in accordance with https://www.ietf.org/rfc/rfc2597.txt[RFC 2597]. +The Drop Precedence bits are contained within the six bit Differentiated +Services Code Point subfield of the IPv4 TOS field or the IPv6 Traffic +Class (TC) field. Specifically the Drop Precedence sub-subfield can be +accessed with a DSCP bit mask of 0x06. When enabled for a given color, +these two bits will be set to Medium Drop Precedence (value 0x4) if the +color is ODP_PACKET_YELLOW, set to High Drop Precedence (value 0x6) if +the color is ODP_PACKET_RED. + +Note that the IPv4 header checksum will be updated - but only if the +IPv4 TOS field actually changes as a result of this setting or the +`odp_tm_ecn_marking()` setting. For IPv6, since there is no header checksum, +nothing else needs to be done. +`drop_prec_marking_supported` boolean in capability structure indicates whether +this feature is supported by the implementation. + === Examples .Create a tm_node chain for two nodes and associate the scheduler
Updates packet marking api documentation to traffic manager user guide Signed-off-by: Balasubramanian Manoharan <bala.manoharan@linaro.org> --- v2: document format update doc/users-guide/users-guide-tm.adoc | 73 +++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+)