Re: [CCAMP] Poll on ODUFlex-related encoding

Hi Fred,

You are correct.

Best Regards

Fatai

From: Fred Gruman [mailto:fgruman@gmail.com]
Sent: Wednesday, February 06, 2013 9:28 AM
To: Lou Berger
Cc: John E Drake; CCAMP; draft-ietf-ccamp-gmpls-ospf-g709v3@tools.ietf.org; draft-ietf-ccamp-gmpls-signaling-g709v3@tools.ietf.org
Subject: Re: [CCAMP] Poll on ODUFlex-related encoding

Hi Lou,
I'm not sure if you are looking at the latest version of G.709 (2/2012), but ODUflex(GFP) now states +/- 100 ppm in Tables 7-2 and 7-8.
Although the client tolerance may be less than 100 ppm, under failure conditions, the local clock tolerance for ODUflex(GFP) maintenance signal generation is 100 ppm.  Thus the ODUflex(GFP) services would needs to support the worse case, which is the maintenance signal (and thus would always be 100 ppm).

Fred

On Tue, Feb 5, 2013 at 4:38 PM, Lou Berger <lberger@labn.net<mailto:lberger@labn.net>> wrote:

John,

See question in-line below.

On 2/5/2013 2:19 PM, John E Drake wrote:
> Snipped, comment inline
>
> Irrespectively Yours,
>
> John
>
>>>    0             1             2             3
>>>   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>>> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>  |  Signal Type  |       N       |        Reserved       |
>>>  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>  |              NVC           |      Multiplier (MT)     |
>>>  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>>  |                      Bit_Rate                       |
>>>  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>> I just wonder are we not better off keeping Tolerance field in
>> signaling and adding a statement in v7 that this field is hardcoded to
>> 100ppm.
>>
>> This has advantage of interworking with earlier draft implementations
>> and is also flexible for various (future/ unknown) client signal types.
>> I.e., we use the same encoding as defined thus far in the document
>> (copying from
>> v6):
>>
>>       0                   1                   2                   3
>>       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
>>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>      |  Signal Type  |       N       |           Tolerance           |
>>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>      |              NVC              |        Multiplier (MT)        |
>>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>      |                            Bit_Rate                           |
>>      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
>>
>> And state that Tolerance MUST be set to 100 ppm.
>
>
> JD: This is a very good idea.
Great.  Thanks for being clear on which option you support.

> 'Per [G.874.1/2011] (or whatever is
> the correct reference) Tolerance MUST be set to 100 ppm.'
>
Is this correct (always 100ppm)?  Fatai/Sergio referred to table 7-2 in
G709 which has 20ppm for most signal types and 100ppm for others.  And
it seems there is some text that got dropped in the latest rev of
G.874.1 (from and earlier amendment).

In your role as ITU-T SG15 liaison manager, can you either figure out
what the right text & reference should be or propose a liaison that we
can send asking the ITU-T for whatever information we need to close this
issue/document?

Thanks,
Lou

>
>>
>>
>> Thanks
>>
>> Regards...Zafar
>>
>>> <snip>
>>
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>
>
>
>
>
>
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