[vnfpool] comment on draft-zong-vnfpool-problem-statement

[Marco Liebsch <[e-mail]>]

Hi Ning, all,



please find some more feedback to the 4th revision of the VNFPool PS draft below. It's more
about a clarification before I can send more detailed comments on the draft.





The draft clarifies about the technical scope, which I understand is limited to redundancy management
and failover handling within a group of VNFs of the same type, the VNF set.
To coordinate between functions of different pools, the draft introduces the Service Control Entity.


Does the Service Control Entity play a role in building a single network function, e.g. a firewall,
from function instances of different pools?



It does not play a role if the complete firewall functionality is provided by a single VNF of a single Pool.

Is this the assumption for VNFPool?



>From Fig. 1 of the draft I understand that the complete function (e.g. the firewall), is provided by a single box
above the Virtualization Platform layer. And each box seems to be a virtual machine.

This would mean that each VNFPool provides a self-contained function, e.g. firewall, web-service, etc.

There is no functional dependency between VNFs of different Pools. Is this understanding correct?



My understanding of how a virtualized network function vNF is built is that it comprises multiple

vNF Components (vNFC) of the same (for function-internal load balancing) and of different types.

Each vNFC is instantiated in a separate virtual machine.

I am still not sure how to reflect this in VNFPool: It may be details that hide inside a VNF as e.g. depicted in
Fig. 1. In such case, the function-internal architecture made from different vNFCs is not visible to VNFPool.



In case VNFPool is concerned with the function-internal architecture made from different vNFCs, Section 3.2
may include such figure:





                  +---------+

                  | VNF-C#z |

                  |         |

                  +---------+

                      ^ |

                      | |

                      | |

                      | v

+---------+       +---------+

| VNF-A#x |<------| VNF-B#y |

|         |------>|         |

+---------+       +---------+

                       ^

                       |

                       |

                       |

                       v

                  +---------+

                  | Client  |

                  +---------+





Sorry that I come up with this request for clarification again.



Best regards,

marco