RE: [RPRWG] 802.17 Outline: Stratum Clock distribution?
David,
Perhaps it was a confusion of terminology on my part. You are correct if we
think in terms of UTC as a stable frequency or rate there is not much
different.
ANSI T1.101 specifies the accuracy and stability of clocks used in Telecom
industry, as well as guidelines for clock distribution.
James Chan
-----Original Message-----
From: David James [mailto:djz@xxxxxxxxxxx]
Sent: Monday, November 26, 2001 11:05 AM
To: Chan, James; Jeanne.De_Jaegher@xxxxxxxxxx
Cc: stds-802-17@xxxxxxxx
Subject: RE: [RPRWG] 802.17 Outline: Stratum Clock distribution?
James,
> Stratum Clock Distribution to me means ANSI T1.101
> Synchronization hierarchy standard.
> This is very different to time-of-day clocks.
Please clarify why these are very different. I had thought
that synchronized time-of-day clocks (when sufficiently
accurate) is a superset of Stratum Clock distribution.
DVJ
David V. James, PhD
Chief Architect
Network Processing Solutions
Data Communications Division
Cypress Semiconductor
110 Nortech Parkway
San Jose, CA 95134
Work: +1.408.942.2010
Cell: +1.650.954.6906
Fax: +1.408.942.2099
Work: djz@xxxxxxxxxxx
Base: dvj@xxxxxxxxxxxx
> -----Original Message-----
> From: Chan, James [mailto:jchan@xxxxxxxxxxxxxxxxx]
> Sent: Wednesday, November 21, 2001 1:33 PM
> To: 'djz@xxxxxxxxxxx'; Jeanne.De_Jaegher@xxxxxxxxxx
> Cc: stds-802-17@xxxxxxxx
> Subject: RE: [RPRWG] 802.17 Outline: Stratum Clock distribution?
>
>
>
> Stratum Clock Distribution to me means ANSI T1.101
> Synchronization hierarchy
> standard. This is very different to time-of-day clocks. Synchronization is
> necessary from PSTN (TDM voice) perspective. It may also be required for a
> RPR network supporting circuit emulation services (there may be other ways
> to do it without synchronization). However, this is an implementation
> specific issue which should not be part of the RPR standard. Individual
> vendors may choose to do it as their differentiator.
>
> I was not aware of stratum clock discussion in the last meeting. Can any
> else shed some light?
>
>
> Regards,
>
> James Chan
>
>
>
>
> -----Original Message-----
> From: David James [mailto:djz@xxxxxxxxxxx]
> Sent: Wednesday, November 21, 2001 10:14 AM
> To: Jeanne.De_Jaegher@xxxxxxxxxx
> Cc: stds-802-17@xxxxxxxx
> Subject: RE: [RPRWG] 802.17 Outline: Stratum Clock distribution?
>
>
>
> Jeanne,
>
> Some physical layers have no provisions for accurately
> synchronizing time-of-day clocks (GMT like clocks) of
> clock slave's to clock masters.
>
> For physical layers without such services, this clause
> describes how such time-of-day clocks can be accurately
> synchronized by MAC-level services.
>
> From IEEE Std 1394 Serial Bus experiences, as well as
> the telecom industry as a whole, the value of synchronous
> transfers is greatly increased if time-of-day clocks
> can also be synchronized.
>
> DVJ
>
>
> David V. James, PhD
> Chief Architect
> Network Processing Solutions
> Data Communications Division
> Cypress Semiconductor
> 110 Nortech Parkway
> San Jose, CA 95134
> Work: +1.408.942.2010
> Cell: +1.650.954.6906
> Fax: +1.408.942.2099
> Work: djz@xxxxxxxxxxx
> Base: dvj@xxxxxxxxxxxx
>
> > -----Original Message-----
> > From: owner-stds-802-17@xxxxxxxxxxxxxxxxxx
> > [mailto:owner-stds-802-17@xxxxxxxxxxxxxxxxxx]On Behalf Of
> > Jeanne.De_Jaegher@xxxxxxxxxx
> > Sent: Wednesday, November 21, 2001 3:17 AM
> > To: stds-802-17@xxxxxxxx
> > Subject: [RPRWG] 802.17 Outline: Stratum Clock distribution?
> >
> >
> >
> >
> >
> > Good morning,
> >
> > Can someone tell me what the section over Stratum Clock
> > Distribution covers?
> >
> >
> > Thank's
> >
> > Jeanne
> >
> >
> >
>