From 55024e8df607ee8eaaa61132e2feb66524d0e407 Mon Sep 17 00:00:00 2001 From: bingwang Date: Fri, 18 Mar 2022 01:16:32 -0700 Subject: [PATCH] Add detailed map Signed-off-by: bingwang --- doc/qos/tunnel_dscp_remapping.md | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/doc/qos/tunnel_dscp_remapping.md b/doc/qos/tunnel_dscp_remapping.md index 1617383eb91..f38bd52d72f 100644 --- a/doc/qos/tunnel_dscp_remapping.md +++ b/doc/qos/tunnel_dscp_remapping.md @@ -117,6 +117,7 @@ Before remapping to queue 4 and 6, both queues are required to be cleared. Hence ``` TC_TO_DSCP_MAP for rewriting DSCP + ```json "TC_TO_DSCP_MAP": { "AZURE_TUNNEL": { @@ -201,6 +202,25 @@ TC remapping requires below SAI attributes change. */ SAI_TUNNEL_ATTR_DECAP_QOS_TC_TO_PRIORITY_GROUP_MAP, ``` +For instance, when we get a traffic flow with DSCP = 3 on T1, the traffic and bounced back traffic is delivered and remapped as below: + +1. Traffic from `T1` to `Standby ToR` + - Traffic mapped to `TC3`, `PG3` and `Queue 3` by port level QoS mapping +2. Bounced back traffic from `Standby ToR` to `T1` + - Traffic arrived at `Standby ToR` in `TC3`, `PG3` and `Queue 3` as per port level QoS mapping + - Packet will be encapped and delivered back to `T1` by `MuxTunnel` + - The outer `DSCP` is rewritten to `2` as specified in `TC_TO_DSCP_MAP|AZURE_TUNNEL` by SAI attribute `SAI_TUNNEL_ATTR_ENCAP_QOS_TC_AND_COLOR_TO_DSCP_MAP`. + - Traffic is delivered in `Queue 2` as specified in `TC_TO_QUEUE_MAP|AZURE_TUNNEL` by SAI attribute `SAI_TUNNEL_ATTR_ENCAP_QOS_TC_TO_QUEUE_MAP` +3. Bounced back traffic from `T1` to `Active ToR` + - Bounced back traffic arrive at `T1` in `Queue 2` and `PG2` by port level QoS mapping + - Bounced back traffic will be routed to `Active ToR` +4. Traffic from `Active ToR` to `Server` + - Traffic arrived at `Active ToR` and will be decapped and delivered to server + - The outer `DSCP` is ignored as the `dscp_mode` for `MuxTunnel` is `PIPE`. The inner `DSCP3` is copied to outer layer + - Traffic is remapped to `TC 3` as specified in `DSCP_TO_TC_MAP|AZURE_TUNNEL` by SAI attribute `SAI_TUNNEL_ATTR_DECAP_QOS_DSCP_TO_TC_MAP` + - Traffic is remapped to `PG 2` as specified in `TC_TO_PRIORITY_GROUP_MAP|AZURE_TUNNEL` by SAI attribute `SAI_TUNNEL_ATTR_DECAP_QOS_TC_TO_PRIORITY_GROUP_MAP` + - Traffic is in `Queue 3` as per port level QoS mapping + - Decapped traffic is delivered to target server ### 5.3 orchagent Code change in orchagent