[VOL-3886] Documentation for using the upstream pbit in the downstream flows
Change-Id: I55bb37215682eda23e5fba3e98e5b6f13a15d9fc
diff --git a/impl/src/main/java/org/opencord/olt/impl/OltFlowService.java b/impl/src/main/java/org/opencord/olt/impl/OltFlowService.java
index adaeeba..cf5fe14 100644
--- a/impl/src/main/java/org/opencord/olt/impl/OltFlowService.java
+++ b/impl/src/main/java/org/opencord/olt/impl/OltFlowService.java
@@ -847,7 +847,11 @@
tagInformation.getTechnologyProfileId(),
subscriberPort), 0);
- // to remark inner vlan header
+ // Upstream pbit is used to remark inner vlan pbit.
+ // Upstream is used to avoid trusting the BNG to send the packet with correct pbit.
+ // this is done because ds mode 0 is used because ds mode 3 or 6 that allow for
+ // all pbit acceptance are not widely supported by vendors even though present in
+ // the OMCI spec.
if (tagInformation.getUsPonCTagPriority() != NO_PCP) {
treatmentBuilder.setVlanPcp((byte) tagInformation.getUsPonCTagPriority());
}