Boundary clock support for ptpd

Ronciak, John john.ronciak at intel.com
Mon Apr 19 13:15:42 EDT 2010


I'm not sure what you are looking for.  The Intel HW that can assist in timestamping 1588 packets is per port.  Which means it really can't be used across ports as for a boundary clock.  This has been brought up as a possible feature in future devices but it hasn't even been accepted for them at this time.

Can you use a SW only solution for your boundary clock?  I think the PTPd could do that.

Cheers,
John
-----------------------------------------------------------
"...that your people will judge you on what you can build, not what you destroy.", B. Obama, 2009 

 

>-----Original Message-----
>From: ptpd-bounces at lists.infradead.org 
>[mailto:ptpd-bounces at lists.infradead.org] On Behalf Of 
>Wolfgang Grandegger
>Sent: Friday, April 16, 2010 7:09 AM
>To: gnn at neville-neil.com
>Cc: ptpd at lists.infradead.org
>Subject: Re: Boundary clock support for ptpd
>
>gnn wrote:
>> On 4/15/10 15:54 , Wolfgang Grandegger wrote:
>>> Hello,
>>>
>>> anybody listening?
>>>
>> 
>> Yes, just a bit slow.
>> 
>>> Wolfgang Grandegger wrote:
>>>> Hello,
>>>>
>>>> I'm currently evaluating ptpd-1.0.0 for IEEE1588 time 
>syncronization
>>>> with MPC8313 boards. I realized that there is an effort to 
>support PTPv2
>>>> (at 
>http://ptpd.svn.sourceforge.net/viewvc/ptpd/branches/v2/). Could
>>>> somebody give a brief status on what is already 
>working/supported. I'm
>>>> especially looking for boundary clock support (master and 
>slave on the
>>>> same board).
>>> In the meantime I made some progress. I cascaded three 
>MPC8313 boards
>>> and measured jitters of +-150ns on the second and +-300ns 
>on the third
>>> board with ptpd *v1*. I will now try with v2 allowing for 
>shorter sync
>>> intervals, which should reduce the jitter significantly.
>>>
>>> I also found some interesting related link. Apart from the PTPDv2
>>> implementation mentioned above, there is another one, 
>especially for the
>>> MPC8313, mentioned here:
>>>
>>> 
>http://forums.freescale.com/t5/Other-Microcontrollers/Open-sour
>ce-for-IEEE-1588-PTP-v2-supporting-MPC831x-to-be/m-p/53829;jses
>sionid=9DF51308EB4B68D57F509D77E77C8DD9
>>> http://code.google.com/p/ptpv2d/
>>>
>>> As I see it, this one also lacks support for recent kernel versions
>>> using the timestamping interface:
>>>
>>> http://lxr.linux.no/linux/Documentation/networking/timestamping.txt
>>>
>>> Is there already an effort supporting that generic 
>interface in ptpd or
>>> ptpdv2?
>> 
>> 
>> I have not looked at that, but I will try to check that out.
>
>It's used for PTP time stamping in a few netdev drivers:
>
>http://lxr.linux.no/#linux+v2.6.33/drivers/net/igb/igb_main.c
>http://marc.info/?l=linux-netdev&m=126389931509102&w=4
>
>Wolfgang.
>
>
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