Feature Request Overview (mandatory - Complete while in New status){_}
{}What user goal or problem do you need to solve?{_} 
Currently, tempest assumes that the test case follows the following scenarios.
1. Having tenant network and external network and it can be accessed via router.
2. FIP on external network can be assigned to an instance.

However, OpenStack itself can configure a provider network, direct access to external network via vlan or flat.
tempest doesn't cover such scenario.

Business justification (mandatory -
This scenario will cover the common scenario in OpenStack.
Implementing this scenario our user don't need to create their own tempest plugin for their usecase.

Functional requirements (mandatory - Complete while in New status){_}
{}What do you want the result of this feature to be? Add as many requirements as needed.{_}

•  Import the instance test cases which require an access via FIP to provider network.
• Run those scenarios.

Describe the customer impact
Current tempest doesn't cover direct provider network access scenario.
Due to that, the user needs to create their own test scenario or do the test manually.

(Optional) Point of contact

• Provide any additional points of contact for this feature request, such as an account executive, SA, or TAM: 
•  TAM

(Optional) Additional links