Thread: [Linuxptp-users] Irregular rate of Delay Request messages

PTP IEEE 1588 stack for Linux

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[Linuxptp-users] Irregular rate of Delay Request messages

From: Ray V. <ree...@gm...> - 2022-08-30 12:27:44

Running ptp4l as a slave, what influences the rate at which Delay Request
Messages are sent out? Pretty standard, the GM send out Announce Messages
every 2 secs, Sync and Follow_Up Messages every second.
The slave sends out Delay Request Messages irregular:  ranging from <1 sec
to 16 sec between subsequent messages. The GM always responds immediately
to a DelayReq.

And, not sure if it is related: the slave ptp4l stays in s0 with ever
decreasing master offset at -max freq...

#
# Port Data Set
#
logAnnounceInterval     1
logSyncInterval         0
logMinDelayReqInterval  0
logMinPdelayReqInterval 0
announceReceiptTimeout  3
syncReceiptTimeout      0
delayAsymmetry          0
fault_reset_interval    4
neighborPropDelayThresh 20000000

Re: [Linuxptp-users] Irregular rate of Delay Request messages

From: Miroslav L. <mli...@re...> - 2022-08-30 12:43:25

On Tue, Aug 30, 2022 at 02:27:22PM +0200, Ray Vanbeek wrote:
> Running ptp4l as a slave, what influences the rate at which Delay Request
> Messages are sent out? Pretty standard, the GM send out Announce Messages
> every 2 secs, Sync and Follow_Up Messages every second.
> The slave sends out Delay Request Messages irregular:  ranging from <1 sec
> to 16 sec between subsequent messages. The GM always responds immediately
> to a DelayReq.

That's a feature of PTP. Clients are required to randomize their
interval of delay requests in order to minimize collisions at the server.

If you see the interval reaching 16 seconds, that means
logMinDelayReqInterval is 3 on the server.

-- 
Miroslav Lichvar

Re: [Linuxptp-users] Irregular rate of Delay Request messages

From: Ray V. <ree...@gm...> - 2022-08-30 13:29:18

Ah, that explains it. Thanks, Miroslav!

And what about an ever decreasing master offset value at -max freq?
I assume the master offset value is in nanosecs? It seems that in 120
seconds, the master offset value decreases with appr 90 secs

On Tue, Aug 30, 2022 at 2:43 PM Miroslav Lichvar <mli...@re...>
wrote:

> On Tue, Aug 30, 2022 at 02:27:22PM +0200, Ray Vanbeek wrote:
> > Running ptp4l as a slave, what influences the rate at which Delay Request
> > Messages are sent out? Pretty standard, the GM send out Announce Messages
> > every 2 secs, Sync and Follow_Up Messages every second.
> > The slave sends out Delay Request Messages irregular:  ranging from <1
> sec
> > to 16 sec between subsequent messages. The GM always responds immediately
> > to a DelayReq.
>
> That's a feature of PTP. Clients are required to randomize their
> interval of delay requests in order to minimize collisions at the server.
>
> If you see the interval reaching 16 seconds, that means
> logMinDelayReqInterval is 3 on the server.
>
> --
> Miroslav Lichvar
>
>

Re: [Linuxptp-users] Irregular rate of Delay Request messages

From: Miroslav L. <mli...@re...> - 2022-08-30 14:33:42

On Tue, Aug 30, 2022 at 03:28:51PM +0200, Ray Vanbeek wrote:
> Ah, that explains it. Thanks, Miroslav!
> 
> And what about an ever decreasing master offset value at -max freq?
> I assume the master offset value is in nanosecs? It seems that in 120
> seconds, the master offset value decreases with appr 90 secs

The offset is in nanoseconds. That sounds like a bug in driver/hw.
What do you use? Maybe someone will have a better suggestion.

-- 
Miroslav Lichvar

Re: [Linuxptp-users] Irregular rate of Delay Request messages

From: Ray V. <ree...@gm...> - 2022-08-31 08:46:06

I use a I219-LM chip with the e1000e driver:
> ethtool -i eth1
driver: e1000e
version: 2.3.2-k
firmware-version: 0.8-4
expansion-rom-version:
bus-info: 0000:00:1f.6
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: no

Which is rather old, I see... (I'm stuck to an also rather old Fedora Core
25 linux).
On the other hand, the sources include a ptp.c file from/by Richard
Cochran...
Is this version flagged as buggy?


On Tue, Aug 30, 2022 at 4:36 PM Miroslav Lichvar <mli...@re...>
wrote:

> On Tue, Aug 30, 2022 at 03:28:51PM +0200, Ray Vanbeek wrote:
> > Ah, that explains it. Thanks, Miroslav!
> >
> > And what about an ever decreasing master offset value at -max freq?
> > I assume the master offset value is in nanosecs? It seems that in 120
> > seconds, the master offset value decreases with appr 90 secs
>
> The offset is in nanoseconds. That sounds like a bug in driver/hw.
> What do you use? Maybe someone will have a better suggestion.
>
> --
> Miroslav Lichvar
>
>
>
> _______________________________________________
> Linuxptp-users mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxptp-users
>

Re: [Linuxptp-users] Irregular rate of Delay Request messages

From: Jacob K. <jac...@in...> - 2022-08-31 20:59:56


On 8/31/2022 1:45 AM, Ray Vanbeek wrote:
> I use a I219-LM chip with the e1000e driver:
>> ethtool -i eth1
> driver: e1000e
> version: 2.3.2-k
> firmware-version: 0.8-4
> expansion-rom-version:
> bus-info: 0000:00:1f.6
> supports-statistics: yes
> supports-test: yes
> supports-eeprom-access: yes
> supports-register-dump: yes
> supports-priv-flags: no
> 
> Which is rather old, I see... (I'm stuck to an also rather old Fedora
> Core 25 linux).
> On the other hand, the sources include a ptp.c file from/by Richard
> Cochran...
> Is this version flagged as buggy?
> 
> 

There have been a lot of bug fixes since then. I would suggest updating
to a new kernel, but if thats not an option you might try the
out-of-tree driver available from
https://sourceforge.net/projects/e1000/files/e1000e%20historic%20archive/

We no longer provide active support or releases for these since we have
moved to only supporting the upstream driver for this product. However,
that decision was made long after the life of Fedora Core 25, so the
latest version here might work for you. No guarantee.

Your best bet is to update your kernel.

Thanks,
Jake

> On Tue, Aug 30, 2022 at 4:36 PM Miroslav Lichvar <mli...@re...
> <mailto:mli...@re...>> wrote:
> 
>     On Tue, Aug 30, 2022 at 03:28:51PM +0200, Ray Vanbeek wrote:
>     > Ah, that explains it. Thanks, Miroslav!
>     >
>     > And what about an ever decreasing master offset value at -max freq?
>     > I assume the master offset value is in nanosecs? It seems that in 120
>     > seconds, the master offset value decreases with appr 90 secs
> 
>     The offset is in nanoseconds. That sounds like a bug in driver/hw.
>     What do you use? Maybe someone will have a better suggestion.
> 
>     -- 
>     Miroslav Lichvar
> 
> 
> 
>     _______________________________________________
>     Linuxptp-users mailing list
>     Lin...@li...
>     <mailto:Lin...@li...>
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>     <https://lists.sourceforge.net/lists/listinfo/linuxptp-users>
> 
> 
> 
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