Sorry about that. Fixed. On Monday, May 16, 2016, Bala Manoharan <[email protected]> wrote:
> FYI > > @Bill: Looks like you did a reply instead of reply-all :) > > Regards, > Bala > > ---------- Forwarded message ---------- > From: Bill Fischofer <[email protected] <javascript:;>> > Date: 16 May 2016 at 20:20 > Subject: Re: [PATCHv2] doc: users-guide: add packet marking documentation > To: Balasubramanian Manoharan <[email protected] <javascript:;>> > > > > > On Mon, May 16, 2016 at 2:51 AM, Balasubramanian Manoharan > <[email protected] <javascript:;>> wrote: > > > > Updates packet marking api documentation to traffic manager user guide > > > > Signed-off-by: Balasubramanian Manoharan <[email protected] > <javascript:;>> > > > Reviewed-and-tested-by: Bill Fischofer <[email protected] > <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 > > > _______________________________________________ lng-odp mailing list [email protected] https://lists.linaro.org/mailman/listinfo/lng-odp
