Re: [sfc] is current SFC architecture supporting different types of SFC header formats?

["Carlos Pignataro (cpignata)" <[e-mail]>]

Georgios,

> On Dec 4, 2014, at 10:33 AM, Georgios Karagiannis <[e-mail]> wrote:
> 
> Hi Carlos,
> 
> Thank you very much for the clarification!
> 
>> I see — this is a question for draft-boucadair-sfc-design-analysis and not for
>> draft-ietf-sfc-architecture. Meaning, it would be up to the proposed
>> encapsulation to show how they realize the functions of the architecture.
>> 
>> That said, I do not see an “SF Map Index” in the architecture document, for
>> example.
> 
> Georgios: Thanks, I see, so additional functions need to be added to the SFC architecture if one would like to support the Single Marking Code Point - like format.
> 

No — it’s actually the other way around. The architecture does not retrofit a format proposal.

As Joel said, it’s not just “any” SFC encap proposal. The architecture made choices, and encap proposals realize the architecture with different encodings.

> What about the Explicit Route List. Section 5.6 of the SFC architecture draft mentions that "This architecture prescribes additional information being added to packets to identify service function paths and often to represent metadata. 
> Can such an Explicit Route List being considered as metadata?
> 

The architecture describes what is necessary in the SFC encapsulation, what is metadata, and what the SFC encapsulation is not. 

Thanks,

Carlos.

> Best regards,
> Georgios
> 
> 
> 
> 
> 
>> -----Original Message-----
>> From: Carlos Pignataro (cpignata) [mailto:[e-mail]]
>> Sent: Thursday, December 04, 2014 4:18 PM
>> To: Georgios Karagiannis
>> Cc: [e-mail]
>> Subject: Re: [sfc] is current SFC architecture supporting different types of
>> SFC header formats?
>> 
>> Hi Georgios,
>> 
>> Please see inline.
>> 
>>> On Dec 4, 2014, at 9:40 AM, Georgios Karagiannis
>> <[e-mail]> wrote:
>>> 
>>> Hi Carlos,
>>> 
>>> Please note that I do not mean to use different SFC encapsulations
>> simultaneously.
>>> 
>> 
>> Thanks for the clarification.
>> 
>>> From what I understood from IETF'91 meeting discussions, the Generic SFC
>> encapsulation technique has not yet been selected by the SFC WG.
>>> 
>>> I think that this means that the SFC architecture draft cannot be in
>>> favor for one specific SFC encapsulation technique and at the same time
>> excluding other techniques.
>>> 
>> 
>> Yes. Again, the SFC architecture document does not concern itself or take any
>> position on any specifics for any encapsulation format. It does specify the
>> functions that the SFC encapsulation need to fulfill.
>> 
>>> My question is:
>>> 
>>> Can the following two SFC encapsulation techniques be supported by the
>> functions described in the SFC architecture draft?:
>>> 
>>> o) Single Marking Code Point, like format, see section 5.1 on boucadair
>> draft, see below.
>>> 
>>> o) Explicit Route List, like format, see section 5.3 on boucadair draft, see
>> below.
>>> 
>> 
>> I see — this is a question for draft-boucadair-sfc-design-analysis and not for
>> draft-ietf-sfc-architecture. Meaning, it would be up to the proposed
>> encapsulation to show how they realize the functions of the architecture.
>> 
>> That said, I do not see an “SF Map Index” in the architecture document, for
>> example.
>> 
>> Thanks,
>> 
>> Carlos.
>> 
>>> http://www.ietf.org/id/draft-boucadair-sfc-design-analysis-03.txt
>>> 
>>> Best regards,
>>> Georgios
>>> 
>>> 
>>> 
>>> 
>>>> -----Original Message-----
>>>> From: Carlos Pignataro (cpignata) [mailto:[e-mail]]
>>>> Sent: Thursday, December 04, 2014 3:02 PM
>>>> To: Georgios Karagiannis
>>>> Cc: [e-mail]
>>>> Subject: Re: [sfc] is current SFC architecture supporting different
>>>> types of SFC header formats?
>>>> 
>>>> Hi, Georgios,
>>>> 
>>>> Do you mean different SFC Encapsulations simultaneously? The SFC
>>>> charter
>>>> says:
>>>> 
>>>> <snip>
>>>> 3. Generic SFC Encapsulation: This document will describe a single
>>>>  service-level data plane encapsulation format that:
>>>> 
>>>> </snip>
>>>> 
>>>> Because interoperability is the goal.
>>>> 
>>>> Looking at that section, the terminology does not seem to align to
>>>> the arch and problem-statement documents. Also, that section seems to
>>>> describe a pseudo-format, not a format. The architecture describes
>>>> the functions in Section 4.1 and other places.
>>>> 
>>>> Thanks,
>>>> 
>>>> Carlos.
>>>> 
>>>> On 12/4/14, 8:55 AM, "Georgios Karagiannis"
>>>> <[e-mail]> wrote:
>>>> 
>>>>> Hi Carlos,
>>>>> 
>>>>> Thanks for your answer!
>>>>> 
>>>>> Does this mean that the SFC architecture is allowing the use of
>>>>> different Service Function Chaining Header (SFC encapsulation) formats?
>>>>> 
>>>>> I am referring to the different SFC encapsulation formats that are
>>>>> discussed in section 5 of the following ID:
>>>>> http://www.ietf.org/id/draft-boucadair-sfc-design-analysis-03.txt
>>>>> 
>>>>> Best regards,
>>>>> Georgios
>>>>> 
>>>>> 
>>>>>> -----Original Message-----
>>>>>> From: Carlos Pignataro (cpignata) [mailto:[e-mail]]
>>>>>> Sent: Thursday, December 04, 2014 2:46 PM
>>>>>> To: Georgios Karagiannis
>>>>>> Cc: [e-mail]
>>>>>> Subject: Re: [sfc] is current SFC architecture supporting different
>>>>>> types of  SFC header formats?
>>>>>> 
>>>>>> Hi, Georgios,
>>>>>> 
>>>>>> The SFC architecture document concerns itself with the functions
>>>>>> and not the  format.
>>>>>> 
>>>>>> Thanks,
>>>>>> 
>>>>>> Carlos.
>>>>>> 
>>>>>>> On Dec 4, 2014, at 5:17 AM, Georgios Karagiannis
>>>>>> <[e-mail]> wrote:
>>>>>>> 
>>>>>>> Hi all,
>>>>>>> 
>>>>>>> Please note that I was reviewing the SFC architecture draft, see
>>>>>> below, and
>>>>>> I have a question:
>>>>>>> http://www.ietf.org/id/draft-ietf-sfc-architecture-02.txt
>>>>>>> 
>>>>>>> 
>>>>>>> Can you please let me know if the current version of the SFC
>>>>>>> architecture allows the use of different Service Function Chaining
>>>>>> Header
>>>>>> formats?
>>>>>>> 
>>>>>>> These formats and their analysis can be found in Section 5 of the
>>>>>> following
>>>>>> draft:
>>>>>>> 
>>>>>>> http://www.ietf.org/id/draft-boucadair-sfc-design-analysis-03.txt
>>>>>>> 
>>>>>>> 
>>>>>>> If that is not the case, please elaborate why.
>>>>>>> 
>>>>>>> Best regards,
>>>>>>> Georgios
>>>>>>> 
>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> sfc mailing list
>>>>>>> [e-mail]
>>>>>>> https://www.ietf.org/mailman/listinfo/sfc
>>>>> 
>>> 
>