diff --git a/doc/ChangeLog.md b/doc/ChangeLog.md
index f0615b84..93bd8317 100644
--- a/doc/ChangeLog.md
+++ b/doc/ChangeLog.md
@@ -4,6 +4,15 @@ Change Log
All notable changes to the project are documented in this file.
+[v24.10.2][UNRELEASED]
+-------------------------
+
+### Changes
+
+- Updated QoS documentation with pictures and more information on VLAN
+ interface ingress/egress priority handling.
+
+
[v24.10.1][] - 2024-10-18
-------------------------
@@ -1244,7 +1253,7 @@ Supported YANG models in addition to those used by sysrepo and netopeer:
- N/A
[buildroot]: https://buildroot.org/
-[UNRELEASED]: https://github.com/kernelkit/infix/compare/v24.10.0...HEAD
+[UNRELEASED]: https://github.com/kernelkit/infix/compare/v24.10.1...HEAD
[v24.10.1]: https://github.com/kernelkit/infix/compare/v24.10.0...v24.10.1
[v24.10.0]: https://github.com/kernelkit/infix/compare/v24.09.0...v24.10.0
[v24.09.0]: https://github.com/kernelkit/infix/compare/v24.08.0...v24.09.0
diff --git a/doc/img/qos-complex.svg b/doc/img/qos-complex.svg
new file mode 100644
index 00000000..9b322c29
--- /dev/null
+++ b/doc/img/qos-complex.svg
@@ -0,0 +1,3 @@
+
+
+
\ No newline at end of file
diff --git a/doc/img/qos-hw-mvls.svg b/doc/img/qos-hw-mvls.svg
new file mode 100644
index 00000000..9a646274
--- /dev/null
+++ b/doc/img/qos-hw-mvls.svg
@@ -0,0 +1,3 @@
+
+
+
\ No newline at end of file
diff --git a/doc/img/qos-vlan-iface.svg b/doc/img/qos-vlan-iface.svg
new file mode 100644
index 00000000..1c604c74
--- /dev/null
+++ b/doc/img/qos-vlan-iface.svg
@@ -0,0 +1,3 @@
+
+
+
\ No newline at end of file
diff --git a/doc/qos.md b/doc/qos.md
index 1e52e4ae..25e3b047 100644
--- a/doc/qos.md
+++ b/doc/qos.md
@@ -12,14 +12,6 @@ packets to drop and which ones to prioritize, such that critical
services remain operational.
-## Software Forwarded Traffic
-
-For packets which are processed by a CPU, i.e. typically routed
-traffic, and bridged traffic between interfaces that do not belong to
-the same hardware switching domain, an [nftables container][1] can be
-used to define a QoS policy.
-
-
## Hardware Forwarded Traffic
The default QoS policy for flows which are offloaded to a switching
@@ -34,6 +26,14 @@ chips in this family where limited to 4 output queues per port, this
documentation is _only_ valid for newer generations with 8 output
queues per port.
+
+
+The picture illustrates packets having their priority determined at
+ingress, here interface _e1_ and _e3_. In this example, both packets
+are forwarded to the same outgoing interface (_e2_), subject to output
+queueing. The sections below provides more information on these
+topics.
+
#### Default Policy
##### Queueing
@@ -73,6 +73,41 @@ set to the 3 most significant bits of it. If no priority information
is available in the frame on ingress (i.e. untagged non-IP), then
packets will egress out of tagged ports with PCP set to 0.
+## Software Forwarded Traffic
+
+For packets which are processed by a CPU, i.e. typically routed
+traffic, and bridged traffic between interfaces that do not belong to
+the same hardware switching domain, an [nftables container][1] can be
+used to define a QoS policy.
+
+For VLAN interfaces, Infix provides support for mapping the Priority
+Code Point (PCP) to internal priority on ingress, and the reverse on
+egress.
+
+
+
+
+These `ingress-qos` and `egress-qos` settings are done per VLAN, both
+defaulting to '0'. The example below shows how to keep the PCP priority
+for packets being routed between two VLAN interfaces.
+
+```
+admin@example:/config/> edit interface e1.10
+admin@example:/config/interface/e1.10/> set vlan ingress-qos priority from-pcp
+admin@example:/config/interface/e1.10/> up
+admin@example:/config/> edit interface e1.20
+admin@example:/config/interface/e1.20/> set vlan egress-qos pcp from-priority
+admin@example:/config/interface/e1.20/> leave
+admin@example:/>
+```
+
+## A complex example
+
+The picture below shows a packet flow being subject both to software
+forwarding and hardware offloading.
+
+
+
[1]: container.md#application-container-nftables
[2]: https://en.wikipedia.org/wiki/IEEE_802.1Q