QoS DSCP marking support

RFE: https://bugs.launchpad.net/neutron/+bug/1468353

Problem Description

The current QoS API does not provide functionality to mark outgoing network traffic with a DSCP value. This proposal talks about enhancing the existing QoS API’s by adding DSCP marking support. The functionality will make use of the Open vSwitch support for adding DSCP marks to the outbound network traffic.

Proposed Change

We propose an update to the QoS API and OVS driver to support DSCP marks. Valid DSCP mark values can be between 0 and 56, except 2-6, 42, 44, and 50-54.

This will serve as the reference implementation for how to use the QoS API to manage DSCP marks using the OVS driver.

Data Model Impact

The model follows the way that the QoS Bandwidth Limiting functionality applies to QoS policies by adding a QosDscpMarkingRule table.

The QosDscpMarkingRule model would look like:

Attribute Name Type Access Default Value Validation/ Conversion Description
qos_policy_id string (UUID) RO, all N/A uuid QoSPolicy reference
dscp_mark integer RW, tenant N/A 0 and 56, except 2-6, 42, 44, and 50-54 DSCP Mark

REST API Impact

Proposed attribute:

SUB_RESOURCE_ATTRIBUTE_MAP = {
   'dscp_marking_rules':{
        'parent': {'collection_name': 'policies',
                   'member_name': 'policy'},
        'parameters': dict(QOS_RULE_COMMON_FIELDS,
            **{'dscp_mark': {
                'allow_post': True, 'allow_put': True,
                'convert_to': attr.convert_to_int,
                'is_visible': True, 'default': None,
                'validate': {'type:values': common_constants.
                            VALID_DSCP_MARKS}}})
              })
        }
}

Sample REST calls:

GET /v2.0/qos/policies

Response:
{
    "policy": {
        "name": "AF32",
        "description": "This policy marks DSCP outgoing AF32 traffic for DTV Control",
        "shared": "False"
     }
}

GET /v2.0/qos/policies/<policy-uuid>

Response:
{
    "policy": {
        "tenant_id": "<tenant-id>",
        "id": "<id>",
        "name": "AF32",
        "description": "This policy marks DSCP outgoing AF32 traffic for DTV Control",
        "shared": False,
        "dscp_marking_rules": [{
            "id": "<id>",
            "policy_id": "<policy-uuid>",
            "dscp_mark": 16
        }]
     }
}

POST /v2.0/qos/policies/<policy-uuid>/dscp-marking-rules/
{
    "dscp_marking_rule": {
        "dscp_mark": 16
    }
}

Response:
{
    "dscp_marking_rule":{
        "id": "<id>",
        "policy_id": "<policy-uuid>",
        "dscp_mark": 16
    }
}

PUT /v2.0/qos/policies/<policy-uuid>/dscp-marking-rules/<rule-uuid>
{
    "dscp_marking_rule": {
        "dscp_mark": 8
    }
}

Response:
{
    "dscp_marking_rule":{
        "id": "<id>",
        "policy_id": "<policy-uuid>",
        "dscp_mark": 8
    }
}

Command Line Client Impact

  • qos-dscp-marking-rule-create <policy-id> –dscp_mark <value>
  • qos-dscp-marking-rule-show <mark-rule-id> <policy-id>
  • qos-dscp-marking-rule-list <policy-id>
  • qos-dscp-marking-rule-update <mark-rule-id> <policy-id> –dscp_mark <value>
  • qos-dscp-marking-rule-delete <mark-rule-id> <policy-id>

Security Impact

None

Notifications Impact

None

Performance Impact

None

IPv6 Impact

None

Other Deployer Impact

Deployers may need to configure the specific QoS driver / ML2 agent extension.

Developer Impact

None

Community Impact

The ability to set DSCP marks on QoS policies on ports or networks using OVS.

Implementation

Assignee(s)

  • victor-r-howard
  • nate-johnston
  • james-reeves5546
  • margaret-frances

Work Items

  • Versioned DB objects for the new rule type
  • API changes to allow for DSCP API modifications
  • Client changes to allow for DSCP values being set
  • Openflow integration within OVS driver to add qos_dscp marking functionality

Dependencies

API-tests

  • Creating DSCP values
  • Updating DSCP values
  • Deleting DSCP values
  • Listing DSCP values
  • Showing a DSCP Value

Functional Tests

Functional tests will be used to verify system interactions:

  • Setting DSCP values
  • Updating DSCP values
  • Deleting DSCP values
  • Listing DSCP values
  • Ensure traffic is using DSCP marks outbound

Fullstack Tests

  • Setting a QoS policy for marking on a port from API, inspecting that the low-level system bits are set to do DSCP correctly
  • Updating QoS policy, and checking the low bits (DSCP mark bits)
  • Deleting QoS policy and verifying all the DSCP rules are deleted properly or not

Documentation Impact

User Documentation

Existing Networking Guide will be updated for this feature.

Existing CLI guide will be updated for this feature.

Developer Documentation

Existing QoS devref document will be updated for this feature.

API Documentation

Existing QoS API documentation will be updated for this feature.