| Message ID | DBXPR07MB479E7752ADDF5FC0323D1DCEA010@DBXPR07MB479.eurprd07.prod.outlook.com |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [ovs-dev] bfd: Send BFD packets with DSCP CS6 | expand |
Gentle reminder to review this patch. Regards, Pradeep -----Original Message----- From: ovs-dev-bounces@openvswitch.org [mailto:ovs-dev-bounces@openvswitch.org] On Behalf Of Venkatesan Pradeep Sent: Monday, December 25, 2017 10:29 PM To: dev@openvswitch.org Subject: [ovs-dev] [PATCH] bfd: Send BFD packets with DSCP CS6 Send BFD packets with TOS value equivalent to DSCP CS6 so that the network can apply the right QoS for those packets. This can help avoid BFD flaps due to network congestion. Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> --- lib/bfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bfd.c b/lib/bfd.c index 40cd0be..8d291bb 100644 --- a/lib/bfd.c +++ b/lib/bfd.c @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, ip->ip_ihl_ver = IP_IHL_VER(5, 4); ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); ip->ip_ttl = MAXTTL; - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; ip->ip_proto = IPPROTO_UDP; put_16aligned_be32(&ip->ip_src, bfd->ip_src); put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); _______________________________________________ dev mailing list dev@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
Hi, Acked-by: Zoltan Balogh <zoltan.balogh@ericsson.com> Ben, is there a chance to get this into 2.9? Best regards, Zoltan > -----Original Message----- > From: ovs-dev-bounces@openvswitch.org [mailto:ovs-dev-bounces@openvswitch.org] On Behalf Of Venkatesan Pradeep > Sent: Wednesday, January 10, 2018 6:02 AM > To: dev@openvswitch.org > Subject: Re: [ovs-dev] [PATCH] bfd: Send BFD packets with DSCP CS6 > > Gentle reminder to review this patch. > > Regards, > > Pradeep > > -----Original Message----- > From: ovs-dev-bounces@openvswitch.org [mailto:ovs-dev-bounces@openvswitch.org] On Behalf Of Venkatesan Pradeep > Sent: Monday, December 25, 2017 10:29 PM > To: dev@openvswitch.org > Subject: [ovs-dev] [PATCH] bfd: Send BFD packets with DSCP CS6 > > Send BFD packets with TOS value equivalent to DSCP CS6 so that the network can apply the right QoS for those > packets. This can help avoid BFD flaps due to network congestion. > > Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> > --- > lib/bfd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/bfd.c b/lib/bfd.c > index 40cd0be..8d291bb 100644 > --- a/lib/bfd.c > +++ b/lib/bfd.c > @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, > ip->ip_ihl_ver = IP_IHL_VER(5, 4); > ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); > ip->ip_ttl = MAXTTL; > - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; > + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; > ip->ip_proto = IPPROTO_UDP; > put_16aligned_be32(&ip->ip_src, bfd->ip_src); > put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
Can you provide a reference to something that helps me understand why the new value is the "correct" one? This is not my area of expertise and all I learn from the commit message is an assertion that the new value is better. Thanks, Ben. On Mon, Dec 25, 2017 at 04:59:22PM +0000, Venkatesan Pradeep wrote: > Send BFD packets with TOS value equivalent to DSCP CS6 so that the network > can apply the right QoS for those packets. This can help avoid BFD flaps due > to network congestion. > > Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> > --- > lib/bfd.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/bfd.c b/lib/bfd.c > index 40cd0be..8d291bb 100644 > --- a/lib/bfd.c > +++ b/lib/bfd.c > @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, > ip->ip_ihl_ver = IP_IHL_VER(5, 4); > ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); > ip->ip_ttl = MAXTTL; > - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; > + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; > ip->ip_proto = IPPROTO_UDP; > put_16aligned_be32(&ip->ip_src, bfd->ip_src); > put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
On 01/22/2018 03:36 PM, Ben Pfaff wrote: > Can you provide a reference to something that helps me understand why > the new value is the "correct" one? This is not my area of expertise > and all I learn from the commit message is an assertion that the new > value is better. here is a short declaration: http://www.ciscopress.com/articles/article.asp?p=357102&seqNum=4 A long dissertation: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book/QoSIntro.html But in a nutshell: Network engineers create various queue/drop policies based upon precedence. Routing protocols are considered high priority/high precedence. During link saturation events, packets will get dropped. By creating an egress policy where packets marked by CS6 are allowed front-of-the-queue status, one can be sure that hello's from the various protocols arrive when they need to, without delay and without loss. On the other hand, if the hellos are dropped as part of normal traffic operations, then traffic routing will flap, leading to further congestion and drops. CS6 is a 'well known' marker to network engineers. In many vendor's gear, it is automatically assigned to routing protocol packets. Since OVS does not perform queuing, and leaves that to the kernel edge operations, the queue policies can be used to ensure timely egress of the BFD packets during high utilization events. > > Thanks, > > Ben. > > On Mon, Dec 25, 2017 at 04:59:22PM +0000, Venkatesan Pradeep wrote: >> Send BFD packets with TOS value equivalent to DSCP CS6 so that the network >> can apply the right QoS for those packets. This can help avoid BFD flaps due >> to network congestion. >> >> Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> >> --- >> lib/bfd.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/lib/bfd.c b/lib/bfd.c >> index 40cd0be..8d291bb 100644 >> --- a/lib/bfd.c >> +++ b/lib/bfd.c >> @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, >> ip->ip_ihl_ver = IP_IHL_VER(5, 4); >> ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); >> ip->ip_ttl = MAXTTL; >> - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; >> + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; >> ip->ip_proto = IPPROTO_UDP; >> put_16aligned_be32(&ip->ip_src, bfd->ip_src); >> put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); >> _______________________________________________ >> dev mailing list >> dev@openvswitch.org >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev >
Hi Raymond, Thanks for providing the references. @Ben - we had previously discussed the proposed change on the ovs-dev mailing list: https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339784.html https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339785.html Thanks, Pradeep -----Original Message----- From: ovs-dev-bounces@openvswitch.org [mailto:ovs-dev-bounces@openvswitch.org] On Behalf Of Raymond Burkholder Sent: Tuesday, January 23, 2018 7:53 AM To: ovs-dev@openvswitch.org Subject: Re: [ovs-dev] [PATCH] bfd: Send BFD packets with DSCP CS6 On 01/22/2018 03:36 PM, Ben Pfaff wrote: > Can you provide a reference to something that helps me understand why > the new value is the "correct" one? This is not my area of expertise > and all I learn from the commit message is an assertion that the new > value is better. here is a short declaration: http://www.ciscopress.com/articles/article.asp?p=357102&seqNum=4 A long dissertation: https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book/QoSIntro.html But in a nutshell: Network engineers create various queue/drop policies based upon precedence. Routing protocols are considered high priority/high precedence. During link saturation events, packets will get dropped. By creating an egress policy where packets marked by CS6 are allowed front-of-the-queue status, one can be sure that hello's from the various protocols arrive when they need to, without delay and without loss. On the other hand, if the hellos are dropped as part of normal traffic operations, then traffic routing will flap, leading to further congestion and drops. CS6 is a 'well known' marker to network engineers. In many vendor's gear, it is automatically assigned to routing protocol packets. Since OVS does not perform queuing, and leaves that to the kernel edge operations, the queue policies can be used to ensure timely egress of the BFD packets during high utilization events. > > Thanks, > > Ben. > > On Mon, Dec 25, 2017 at 04:59:22PM +0000, Venkatesan Pradeep wrote: >> Send BFD packets with TOS value equivalent to DSCP CS6 so that the >> network can apply the right QoS for those packets. This can help >> avoid BFD flaps due to network congestion. >> >> Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> >> --- >> lib/bfd.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/lib/bfd.c b/lib/bfd.c >> index 40cd0be..8d291bb 100644 >> --- a/lib/bfd.c >> +++ b/lib/bfd.c >> @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, >> ip->ip_ihl_ver = IP_IHL_VER(5, 4); >> ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); >> ip->ip_ttl = MAXTTL; >> - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; >> + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; >> ip->ip_proto = IPPROTO_UDP; >> put_16aligned_be32(&ip->ip_src, bfd->ip_src); >> put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); >> _______________________________________________ >> dev mailing list >> dev@openvswitch.org >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > -- Raymond Burkholder ray@oneunified.net https://blog.raymond.burkholder.net -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
Thanks Raymond and Venkatesan. That is exactly the kind of information I wanted. I incorporated all of your references into the commit message and applied this to master and branch-2.9. On Tue, Jan 23, 2018 at 05:35:11AM +0000, Venkatesan Pradeep wrote: > Hi Raymond, > > Thanks for providing the references. > > @Ben - we had previously discussed the proposed change on the ovs-dev mailing list: > https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339784.html > https://mail.openvswitch.org/pipermail/ovs-dev/2017-October/339785.html > > Thanks, > > Pradeep > > -----Original Message----- > From: ovs-dev-bounces@openvswitch.org [mailto:ovs-dev-bounces@openvswitch.org] On Behalf Of Raymond Burkholder > Sent: Tuesday, January 23, 2018 7:53 AM > To: ovs-dev@openvswitch.org > Subject: Re: [ovs-dev] [PATCH] bfd: Send BFD packets with DSCP CS6 > > On 01/22/2018 03:36 PM, Ben Pfaff wrote: > > Can you provide a reference to something that helps me understand why > > the new value is the "correct" one? This is not my area of expertise > > and all I learn from the commit message is an assertion that the new > > value is better. > > here is a short declaration: > > http://www.ciscopress.com/articles/article.asp?p=357102&seqNum=4 > > A long dissertation: > > https://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND/QoS-SRND-Book/QoSIntro.html > > But in a nutshell: > > Network engineers create various queue/drop policies based upon precedence. Routing protocols are considered high priority/high precedence. During link saturation events, packets will get dropped. > By creating an egress policy where packets marked by CS6 are allowed front-of-the-queue status, one can be sure that hello's from the various protocols arrive when they need to, without delay and without loss. On the other hand, if the hellos are dropped as part of normal traffic operations, then traffic routing will flap, leading to further congestion and drops. > > CS6 is a 'well known' marker to network engineers. In many vendor's gear, it is automatically assigned to routing protocol packets. > > Since OVS does not perform queuing, and leaves that to the kernel edge operations, the queue policies can be used to ensure timely egress of the BFD packets during high utilization events. > > > > > > Thanks, > > > > Ben. > > > > On Mon, Dec 25, 2017 at 04:59:22PM +0000, Venkatesan Pradeep wrote: > >> Send BFD packets with TOS value equivalent to DSCP CS6 so that the > >> network can apply the right QoS for those packets. This can help > >> avoid BFD flaps due to network congestion. > >> > >> Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> > >> --- > >> lib/bfd.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/lib/bfd.c b/lib/bfd.c > >> index 40cd0be..8d291bb 100644 > >> --- a/lib/bfd.c > >> +++ b/lib/bfd.c > >> @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, > >> ip->ip_ihl_ver = IP_IHL_VER(5, 4); > >> ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); > >> ip->ip_ttl = MAXTTL; > >> - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; > >> + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; > >> ip->ip_proto = IPPROTO_UDP; > >> put_16aligned_be32(&ip->ip_src, bfd->ip_src); > >> put_16aligned_be32(&ip->ip_dst, bfd->ip_dst); > >> _______________________________________________ > >> dev mailing list > >> dev@openvswitch.org > >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > _______________________________________________ > > dev mailing list > > dev@openvswitch.org > > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > > > > -- > Raymond Burkholder > ray@oneunified.net > https://blog.raymond.burkholder.net > > -- > This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
diff --git a/lib/bfd.c b/lib/bfd.c index 40cd0be..8d291bb 100644 --- a/lib/bfd.c +++ b/lib/bfd.c @@ -612,7 +612,7 @@ bfd_put_packet(struct bfd *bfd, struct dp_packet *p, ip->ip_ihl_ver = IP_IHL_VER(5, 4); ip->ip_tot_len = htons(sizeof *ip + sizeof *udp + sizeof *msg); ip->ip_ttl = MAXTTL; - ip->ip_tos = IPTOS_LOWDELAY | IPTOS_THROUGHPUT; + ip->ip_tos = IPTOS_PREC_INTERNETCONTROL; ip->ip_proto = IPPROTO_UDP; put_16aligned_be32(&ip->ip_src, bfd->ip_src); put_16aligned_be32(&ip->ip_dst, bfd->ip_dst);
Send BFD packets with TOS value equivalent to DSCP CS6 so that the network can apply the right QoS for those packets. This can help avoid BFD flaps due to network congestion. Signed-off-by: Venkatesan Pradeep <venkatesan.pradeep@ericsson.com> --- lib/bfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)