[e2e] Clock Synchronization Protocols/Algorithms
Bob Braden
braden at ISI.EDU
Wed Oct 31 13:07:14 PST 2001
*> From helbakou at nortelnetworks.com Wed Oct 31 13:03:37 2001
*> From: "Hesham Elbakoury" <helbakou at nortelnetworks.com>
*> To: Bill Manning <bmanning at ISI.EDU>
*> Cc: braden at ISI.EDU, end2end-interest at postel.org
*> Subject: RE: [e2e] Clock Synchronization Protocols/Algorithms
*> Date: Wed, 31 Oct 2001 13:02:16 -0800
*> Importance: high
*> X-Priority: 1
*> MIME-Version: 1.0
*> X-Orig: <helbakou at americasm06.nt.com>
*>
*> Hi Bill
*>
*> I would like the jitter to b within 200 usec.
*>
*> How precise NTP can be ?
*>
*> Hesham
*>
As I recall, in one fairly benign (but certainly not jitter-free)
environment, the DARPA testbed network DARTnet, NTP got the errors down
to a few microseconds. The lines were T1 and the routers were Sparc 1+
processors.
Bob Braden
*> -----Original Message-----
*> From: Bill Manning [mailto:bmanning at ISI.EDU]
*> Sent: Wednesday, October 31, 2001 12:43 PM
*> To: Elbakoury, Hesham [SC5:323:EXCH]
*> Cc: braden at ISI.EDU; end2end-interest at postel.org
*> Subject: Re: [e2e] Clock Synchronization Protocols/Algorithms
*>
*>
*>
*> How accurate do you need? NTP can be very precise.
*>
*>
*> %
*> % This message is in MIME format. Since your mail reader does not understand
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*> %
*> % Hi Bob
*> %
*> % I know about NTP. I am looking for other protocols that can provide more
*> % accurate clock synchronization.
*> %
*> % Thanks
*> %
*> % Hesham
*> %
*> % -----Original Message-----
*> % From: Bob Braden [mailto:braden at ISI.EDU]
*> % Sent: Wednesday, October 31, 2001 12:00 PM
*> % To: end2end-interest at postel.org; Elbakoury, Hesham [SC5:323:EXCH]
*> % Subject: Re: [e2e] Clock Synchronization Protocols/Algorithms
*> %
*> %
*> %
*> % *> From end2end-interest-admin at postel.org Wed Oct 31 11:55:34 2001
*> % *> From: "Hesham Elbakoury" <helbakou at nortelnetworks.com>
*> % *> To: end2end-interest at postel.org
*> % *> Importance: high
*> % *> X-Priority: 1
*> % *> MIME-Version: 1.0
*> % *> X-Orig: <helbakou at americasm06.nt.com>
*> % *> Subject: [e2e] Clock Synchronization Protocols/Algorithms
*> % *> X-BeenThere: end2end-interest at postel.org
*> % *> X-Mailman-Version: 2.0.1
*> % *> List-Help: <mailto:end2end-interest-request at postel.org?subject=help>
*> % *> List-Archive: <http://www.postel.org/pipermail/end2end-interest/>
*> % *> Date: Wed, 31 Oct 2001 11:51:01 -0800
*> % *>
*> % *>
*> % *> I am interested to find out what are the protocols (e.g. NTP) that
*> % are
*> % *> developed for clock synchronization and their methods
*> % *> to reduce/eliminate the effect of jitter in the distribution of
*> % *> clock/timestamp informations. This jitter is due to queuing delays
*> and
*> % *> S/W packet processing overhead.
*> % *>
*> % *> Thanks
*> % *>
*> % *> Hesham
*> %
*> % Go to the RFC Editor Web page www.rfc-editor.org and search for "NTP".
*> %
*> % Bob Braden
*> %
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*> % <TITLE>RE: [e2e] Clock Synchronization Protocols/Algorithms</TITLE>
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*> % <BODY>
*> %
*> % <P><FONT SIZE=3D2>Hi Bob</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2> I know about NTP. I am looking for other =
*> % protocols that can provide more accurate clock synchronization.</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2> Thanks</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2> Hesham</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2>-----Original Message-----</FONT>
*> % <BR><FONT SIZE=3D2>From: Bob Braden [<A =
*> % HREF=3D"mailto:braden at ISI.EDU">mailto:braden at ISI.EDU</A>]</FONT>
*> % <BR><FONT SIZE=3D2>Sent: Wednesday, October 31, 2001 12:00 PM</FONT>
*> % <BR><FONT SIZE=3D2>To: end2end-interest at postel.org; Elbakoury, Hesham =
*> % [SC5:323:EXCH]</FONT>
*> % <BR><FONT SIZE=3D2>Subject: Re: [e2e] Clock Synchronization =
*> % Protocols/Algorithms</FONT>
*> % </P>
*> % <BR>
*> % <BR>
*> %
*> % <P><FONT SIZE=3D2> *> From =
*> % end2end-interest-admin at postel.org Wed Oct 31 11:55:34 2001</FONT>
*> % <BR><FONT SIZE=3D2> *> From: "Hesham Elbakoury" =
*> % <helbakou at nortelnetworks.com></FONT>
*> % <BR><FONT SIZE=3D2> *> To: end2end-interest at postel.org</FONT>
*> % <BR><FONT SIZE=3D2> *> Importance: high</FONT>
*> % <BR><FONT SIZE=3D2> *> X-Priority: 1</FONT>
*> % <BR><FONT SIZE=3D2> *> MIME-Version: 1.0</FONT>
*> % <BR><FONT SIZE=3D2> *> X-Orig: =
*> % <helbakou at americasm06.nt.com></FONT>
*> % <BR><FONT SIZE=3D2> *> Subject: [e2e] Clock Synchronization =
*> % Protocols/Algorithms</FONT>
*> % <BR><FONT SIZE=3D2> *> X-BeenThere: =
*> % end2end-interest at postel.org</FONT>
*> % <BR><FONT SIZE=3D2> *> X-Mailman-Version: 2.0.1</FONT>
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*> % gt;</FONT>
*> % <BR><FONT SIZE=3D2> *> Date: Wed, 31 Oct 2001 11:51:01 =
*> % -0800</FONT>
*> % <BR><FONT SIZE=3D2> *> </FONT>
*> % <BR><FONT SIZE=3D2> *> </FONT>
*> % <BR><FONT SIZE=3D2> *> I am interested to =
*> % find out what are the protocols (e.g. NTP) that are</FONT>
*> % <BR><FONT SIZE=3D2> *> developed for clock synchronization and =
*> % their methods </FONT>
*> % <BR><FONT SIZE=3D2> *> to reduce/eliminate =
*> % the effect of jitter in the distribution of</FONT>
*> % <BR><FONT SIZE=3D2> *> clock/timestamp informations. This =
*> % jitter is due to queuing delays and</FONT>
*> % <BR><FONT SIZE=3D2> *> S/W packet processing =
*> % overhead.</FONT>
*> % <BR><FONT SIZE=3D2> *> </FONT>
*> % <BR><FONT SIZE=3D2> *> Thanks</FONT>
*> % <BR><FONT SIZE=3D2> *> </FONT>
*> % <BR><FONT SIZE=3D2> *> Hesham</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2>Go to the RFC Editor Web page www.rfc-editor.org and =
*> % search for "NTP".</FONT>
*> % </P>
*> %
*> % <P><FONT SIZE=3D2>Bob Braden</FONT>
*> % </P>
*> %
*> % </BODY>
*> % </HTML>
*> % ------_=_NextPart_001_01C1624C.0D60AA80--
*> %
*>
*>
*> --
*> --bill
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