Setting 802.1p VLAN priority in PPPoE frames

PPPoE related questions
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marekm
Posts: 12
Joined: 09 Jun 2015, 11:01

Setting 802.1p VLAN priority in PPPoE frames

Post by marekm »

Is it possible (or planned to add such a feature) for accel-ppp listening on VLAN interfaces, to set the 3 CoS bits of 802.1p VLAN priority? It could be useful especially for PPPoE bridged over wireless infrastructure (WMM QoS). Higher priority could be given to LCP frames (use little bandwidth, but need to be reliable to keep the connection up) and by RADIUS to better paying / VoIP customers (possibly also looking at DSCP field in IP traffic encapsulated inside PPPoE) etc. So far, I'm still using Mikrotik as PPPoE server (considering migration to accel-ppp, mainly for Delegated-IPv6-Prefix) but also couldn't find a way to do it there. I can give higher priority to LCP using QoS capabilities of my switch (Nortel 5520, "system classifier" can match specified pattern in frame headers and specified action can change the CoS bits) but that doesn't take into account different customers or VoIP traffic. Linux can set VLAN CoS bits based on skb priority by using "vconfig set_egress_map", but can accel-ppp set the skb priority in the PPPoE frames it sends?
Dmitry
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Joined: 09 Oct 2014, 10:06

Re: Setting 802.1p VLAN priority in PPPoE frames

Post by Dmitry »

marekm wrote:but can accel-ppp set the skb priority in the PPPoE frames it sends?
no, it can't
at least i don't know how to do it
marekm
Posts: 12
Joined: 09 Jun 2015, 11:01

Re: Setting 802.1p VLAN priority in PPPoE frames

Post by marekm »

When sending from user space (such as LCP), use the SO_PRIORITY socket option.
Kernel mode PPPoE frames priority can be set with "tc skbedit priority" action, as I can see pppoe_sendmsg sets skb->priority = sk->sk_priority;
It would be useful to be able to set that from a RADIUS attribute, change on the fly with CoA etc.
Good documentation on Linux tc classifiers/actions may be hard to find, I've just found this:
http://people.netfilter.org/pablo/netde ... ecture.pdf
Dmitry
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Re: Setting 802.1p VLAN priority in PPPoE frames

Post by Dmitry »

ok, i'll look
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