narkive

unknown

1970-01-01 00:00:00 UTC

In the Terminology section you provide the following definitions:

VNF Pool: a group of VNF instances providing the same network
function.

VNF Set: a group of VNF instances that can be used to build network
services.

Maybe the following definitions might provide a clearer view:

VNF Pool: a group of VNF instances providing the same network
function.

VNF Set: a group of VNF instances, each providing a different network function,
which can be used to build network services.

Comment_2: This comment is related to VNFpool and in particular what is meant by: VNF instances providing the same network function? Are you referring to identical VNF instances that are providing the same network function, i.e., virtualized instances of the same network function, or does this definition allow to use VNF instances that are not identical, but when they are used together they form one virtualized network function.
An example of the latter will be to virtualise a server, where the VNF of this server will be composed by a virtualized instance of the used protocol stack, a second virtualized instance of the application running on the server and a third virtualized instance of the data base used by the server. Are you considering this composition of this VNF also a VNF pool?

Comment_3: The problem statement is IMHO not clear. One of the reasons of this fact is that the definition of the VNF pool and the VNF set is not clear enough, see previous two comments. Other reasons are related to the fact that the draft does not clearly explain:
o) why is the reliability challenge mentioned in this draft different than the reliability challenges and their solutions used for the physical devices that are providing the same network function(s) as the mentioned VNF(s), in this draft, are providing.
o) why is the reliability challenge that needs to be solved by the VNFpool (future) WG cannot be solved by the currently existing IETF WGs, such as SFC. The reasons given in Section 6.3 are a bit contradictory. One of the reasons provided in that section is is that the reliability mechanisms in VNFpool are mostly internal to VNF, while another reason, given in the same section, is that the reliability mechanism deals with adjacencies in the VNF set. The latter shows that the mechanisms are not internal to a VNFpool. Please clarify!

Comment_4: Please clarify whether the scope of the reliability solution is only limited within a VNF pool, or is it limited within a VNF set? If the scope is limited to a VNF set, then why are you emphasizing that the reliability mechanisms will not be visible to an SFC like control entity, since a VNF set could form a service function chain, see Figure 2 of the draft.

Comment_5: The draft needs to be more consistent on when the VNF set is used and when the VNF pool is used.

Comment_6: There are also some editorial which need to be worked out in a next version of the draft.

Best regards,
Georgios

________________________________
Van: vnfpool [vnfpool-***@ietf.org] namens Zongning [***@huawei.com]
Verzonden: donderdag 10 april 2014 5:21
Aan: ***@ietf.org
Onderwerp: [vnfpool] New revision of VNFPool Problem Statement posted

Hi, folks,

The new revision (-04) of VNFPool Problem Statement I-D is available on the below page.
https://datatracker.ietf.org/doc/draft-zong-vnfpool-problem-statement/

Here are the major changes:

1) Clarify VNFPool architecture and intended scope.

1. Add new section of VNF Pools before the section of Problem. This new section is mainly to outline our scope based on high level description of VNF Pools architecture.

2. Add text to clarify that we are specifically concerned with reliability (e.g. redundancy model, state sharing) that is managed inside the VNF. We are only concerned with the whole VNF set (or forwarding graph) to the extent that it involves reliability impact on adjacent instances of different VNFs.

3. We focus on reliability mechanisms based on VNF pool. Other VNF management aspects such as scaling, load balancing are out of scope.

2) Update terminologies to define Service Control Entity, and delete Pool User as the pool will be internal to VNF only.

3) Re-arrange the text in section of Problems.

4) Update text of VNF instance performance degradation in section of Problems.

5) Update text of Reliable Transport in section of Problems.

6) Add text to explain why service availability is not in scope in section of Problems.

7) Re-write the section describing the relationship of VNFPool and SFC.

8) Add text of transfer of security states in section of Security Consideration.

We hope that the changes have addressed most of the comments, and reflected most of the suggestions during London BoF.

Please review this new revision. Your further comments and suggestions are highly appreciated!

Thanks.

-Ning

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Hi Ning,
<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
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Please note that I have read the current version of the draft.

This version clearer than the previous version of the draft, but IMHO it is still
not clear enough.<o:p></o:p>
<o:p> </o:p>
The main comments that I have are:<o:p></o:p>
<o:p> </o:p>
Comment_1: It is not clear what are the main differences between a VNF set and a
VNFpool.<o:p></o:p>