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<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>Kevin
, </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>Glenn
Parsons, Dave Duehren and I have all pointed out that the ellipsis was supposed
to be</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>there
but was dropped by the TSB during publication. We had a
Rapporteur's/ Working Party meeting in </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>in
Fall 1999 that confirmed the need to reinstate it. The driver for the
reinstatement was based on </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>the
need we foresaw to extend T.38 to support new features such as V.34
fax. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>And
yes, we all tried to let people know about the issue at the time.
But, it did take a while</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>for
the ITU to document the change, which has created today's issue. In
a related vein,</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>the
fax question also saw that there were variations emerging as new T.38 features
emerged, such</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>as the
TPKT support for TCP/IP, so we agreed to start adding a version to the
T.38. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>New
implementations will need to recognize that there are different versions of T.38
in order to gain </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>proper
interoperation. IP call control will also need to expose versions
during negotiations if</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003>interoperability is to be assured.
</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>Given
where we are, the relevant questions will need to sort this out at the next SG16
meeting</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=354514514-14032003>in
May. Gaining a rough consensus on how to resolve it before
then would be a good thing. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003></SPAN></FONT> </DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=354514514-14032003>James</SPAN></FONT></DIV>
<BLOCKQUOTE
style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; PADDING-LEFT: 5px">
<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Kevin Boyle
[mailto:kboyle@nortelnetworks.com]<BR><B>Sent:</B> Friday, March 14, 2003 9:16
AM<BR><B>To:</B> ITU-SG16@echo.jf.INTEL.COM<BR><B>Subject:</B> Re: T.38
potentially broken by recent Corrigendum<BR><BR></DIV></FONT>
<DIV><SPAN class=712071214-14032003><FONT color=#0000ff face=Arial
size=2>All,</FONT></SPAN></DIV>
<DIV><SPAN class=712071214-14032003></SPAN> </DIV>
<DIV><SPAN class=712071214-14032003></SPAN><SPAN
class=712071214-14032003><FONT color=#0000ff face=Arial size=2>It is my
understanding that the ellipsis was intended to be there, and that it
wasn't until folks started implementing that it was noticed that it
got dropped somewhere between the editor's hands and publication. There
was a TD in the Feb 2000 meeting noting this typo. I can
produce it if anyone wants to see it.</FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2>It is<SPAN
class=712071214-14032003> also my understanding that care was taken to ensure
that all known vendors were made aware of the change at the
time.</SPAN></FONT></FONT></FONT></DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=712071214-14032003></SPAN></FONT></FONT></FONT> </DIV>
<DIV><FONT face=Arial><FONT color=#0000ff><FONT size=2><SPAN
class=712071214-14032003>Kevin</SPAN></FONT></FONT></FONT></SPAN></DIV>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV align=left class=OutlookMessageHeader dir=ltr lang=en-us><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B> Klaghofer Karl
ICN EN HS D 11 [mailto:karl.klaghofer@SIEMENS.COM] <BR><B>Sent:</B> Friday,
March 14, 2003 3:44 AM<BR><B>To:</B>
ITU-SG16@echo.jf.INTEL.COM<BR><B>Subject:</B> AW: T.38 potentially broken by
recent Corrigendum<BR><BR></FONT></DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2>Paul,</FONT></SPAN></DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial size=2>I
fully agree with you, that the T.38 (1998) asn.1 and the Revision of T.38
(2002) asn.1 needs to be backwards compatible. </FONT></SPAN></DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2>Regards,</FONT></SPAN></DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2>Karl Klaghofer</FONT></SPAN></DIV>
<DIV><SPAN class=420224008-14032003><FONT color=#0000ff face=Arial
size=2>Siemens</FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Ursprüngliche Nachricht-----<BR><B>Von:</B> Paul E. Jones
[mailto:paulej@PACKETIZER.COM]<BR><B>Gesendet:</B> Montag, 3. März 2003
03:21<BR><B>An:</B> ITU-SG16@echo.jf.INTEL.COM<BR><B>Betreff:</B> T.38
potentially broken by recent Corrigendum<BR><BR></FONT></DIV>
<DIV><FONT face=Arial>
<DIV><FONT face=Arial>Folks,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I just recently discovered that the ITU-T published
a corrigendum to T.38 (1998) that apparently breaks backward compatibility
for all T.38 devices currently deployed that follow the original 1998
specifications. The particular document in question is Corrigendum
1, which was approved in 2000 and subsequently published in May
2001. You can download the corrigendum document for free from this
site:</FONT></DIV><FONT face=Arial><A
href="http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-T.38">http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-T.38</A></FONT>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>The issue at hand is a change in the ASN.1 syntax
found in Annex A/T.38. The particular data structure is shown
here:</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV>Data-Field ::= SEQUENCE OF SEQUENCE<BR>{<BR>
field-type ENUMERATED<BR> {<BR> hdlc-data,<BR> hdlc-sig-end,<BR> hdlc-fcs-OK,<BR> hdlc-fcs-BAD,<BR> hdlc-fcs-OK-sig-end,<BR> hdlc-fcs-BAD-sig-end,<BR> t4-non-ecm-data,<BR> t4-non-ecm-sig-end<U><FONT
color=#ff0000>,</FONT></U><BR> <U><FONT
color=#ff0000>...</FONT></U><BR> },<BR> field-data OCTET
STRING (SIZE(1..65535)) OPTIONAL<BR>}</DIV>
<DIV><FONT face=Arial></FONT> </DIV></BLOCKQUOTE>
<DIV dir=ltr><FONT face=Arial>The syntactical change was the addition of
an ellipsis at the end of the ENUMERATED "field-type". In the
published 1998 specification, this ellipsis did not exist.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial>What I would like to know is whether this
change impacts your product or not. I am aware of many deployed
devices on the market today that employs the 1998 syntax without this
ellipsis. I would like to find out to what extent this change is
going to present problems for companies
represented on various lists and, if I get sufficient support, I
want to take a contribution to the ITU-T SG16 meeting in May to try to
resolve this problem in such a way as to not break backward compatibility
and interoperability.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial>I am looking forward to your
replies.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial></FONT> </DIV>
<DIV dir=ltr><FONT face=Arial>Kindest Regards,</FONT></DIV>
<DIV dir=ltr><FONT face=Arial>Paul E.
Jones</FONT></DIV></FONT></DIV>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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