IEEE 802.1p priority tagging implementation idea

[Alexey E. Suslikov]

once tracking recent pf changes around tagging capability, i
am started to think about 802.1p. why not?

actually, vlan code is (en|de)capsulation engine, priority is
the altq's land. let's think...

- add the dot1p scheduler, similar to priq, but with priority
field reduced to 3 bits and red-only parameter;
- teach pf 0x8100 ether type;
- tagging with pf is already in -current;
- glue the things above.

so, this is an idea. opinions?

[Henning Brauer]

[ I tried to mail you privately, but your mail setup is borken ]

Post by Alexey E. Suslikov
once tracking recent pf changes around tagging capability, i
am started to think about 802.1p. why not?
actually, vlan code is (en|de)capsulation engine, priority is
the altq's land. let's think...
- add the dot1p scheduler, similar to priq, but with priority
field reduced to 3 bits and red-only parameter;
- teach pf 0x8100 ether type;
- tagging with pf is already in -current;
- glue the things above.
so, this is an idea. opinions?

If I don't have to read a boring "802.1p standard" paper... why not,
if it makes sense. right now I don't know what hides behing .1p.
perhaps I just forgot it.

[Daniel Hartmeier]

Post by Alexey E. Suslikov
- add the dot1p scheduler, similar to priq, but with priority
field reduced to 3 bits and red-only parameter;
- teach pf 0x8100 ether type;
- tagging with pf is already in -current;
- glue the things above.

So you want to assign packets to queues based on the vlan tag?

Don't you see packets for each vlan tag on a specific vlan interface
anyway, so you could use the interface as criteria to assign queues?

Or is that (those 3 bits you mention) something different from the vlan
tag? I guess I might work under the wrong assumption that dot1p == vlan
tags, if so, please correct :)

Daniel

[Henning Brauer]

Post by Daniel Hartmeier

Post by Alexey E. Suslikov
- add the dot1p scheduler, similar to priq, but with priority
field reduced to 3 bits and red-only parameter;
- teach pf 0x8100 ether type;
- tagging with pf is already in -current;
- glue the things above.

So you want to assign packets to queues based on the vlan tag?
Don't you see packets for each vlan tag on a specific vlan interface
anyway, so you could use the interface as criteria to assign queues?
Or is that (those 3 bits you mention) something different from the vlan
tag? I guess I might work under the wrong assumption that dot1p == vlan
tags, if so, please correct :)

vlan tags is dot1q ;-)

[Alexey E. Suslikov]

all 802.1Q tags are 32-bit wide: 16 bit - ether type (0x8100), 3 bit -
priority field (802.1p), 1 bit - currently reserved, 12 bits - vlan
identifier itself.

for example:

10:50:27.647806 0:10:22:fd:eb:3d 0:7:e9:a:10:3c 8100 64: 802.1Q vid 50 pri 0
xxx.xxx.xxx.xxx.791 > yyy.yyy.yyy.yyy.22: . ack 2536 win 17520 [tos 0x10]

here is: 8100 ether type, vid 50 - vlan id, pri 0 - priority field.

some useful information can be found here
http://www.xilinx.com/esp/optical/net_tech/ieee8021p.htm

some of the 802.x standards are available for free at
http://standards.ieee.org/getieee802/portfolio.html

Post by Alexey E. Suslikov
- add the dot1p scheduler, similar to priq, but with priority
field reduced to 3 bits and red-only parameter;
- teach pf 0x8100 ether type;
- tagging with pf is already in -current;
- glue the things above.

DH> So you want to assign packets to queues based on the vlan tag?
DH> Don't you see packets for each vlan tag on a specific vlan interface
DH> anyway, so you could use the interface as criteria to assign queues?
DH> Or is that (those 3 bits you mention) something different from the vlan
DH> tag? I guess I might work under the wrong assumption that dot1p == vlan
DH> tags, if so, please correct :)
DH> Daniel