RE: [Speechsc] message-length clarification
"Carter, Jerry" <jerry.carter@nuance.com> Wed, 19 April 2006 14:19 UTC
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1FWDWs-0001vq-PW; Wed, 19 Apr 2006 10:19:38 -0400
Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1FWDWr-0001tn-EJ for speechsc@ietf.org; Wed, 19 Apr 2006 10:19:37 -0400
Received: from mx3.scansoft.com ([198.71.73.26]) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1FWDWp-00060h-UK for speechsc@ietf.org; Wed, 19 Apr 2006 10:19:37 -0400
Received: from pb-exchcon2.nuance.com ([10.1.4.118]RDNS failed) by mx3.scansoft.com with InterScan Message Security Suite; Wed, 19 Apr 2006 10:20:27 -0400
Received: by pb-exchcon2.pb.scansoft.com with Internet Mail Service (5.5.2658.27) id <2ZTTXM3B>; Wed, 19 Apr 2006 10:19:35 -0400
Message-ID: <F8940C21CD563F49BC884A274C4653DF03E50DF5@bn-exch1.speechworks.com>
From: "Carter, Jerry" <jerry.carter@nuance.com>
To: speechsc@ietf.org
Subject: RE: [Speechsc] message-length clarification
Date: Wed, 19 Apr 2006 10:19:34 -0400
MIME-Version: 1.0
X-Mailer: Internet Mail Service (5.5.2658.27)
Content-Type: text/plain
X-Spam-Score: 1.2 (+)
X-Scan-Signature: df1883a27a831c1ea5e8cfe5eb3ad38e
X-BeenThere: speechsc@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Speech Services Control Working Group <speechsc.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/speechsc>, <mailto:speechsc-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:speechsc@ietf.org>
List-Help: <mailto:speechsc-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/speechsc>, <mailto:speechsc-request@ietf.org?subject=subscribe>
Errors-To: speechsc-bounces@ietf.org
I believe that Dave Burke's order correctly captures the discussion. There was a preference for removing the message-length entirely. > -----Original Message----- > From: Burger, Eric [mailto:EBurger@cantata.com] > Sent: Tuesday, April 18, 2006 5:52 PM > To: Dave Burke; Corby Anderson; Brett Gavagni > Cc: speechsc@ietf.org; Shanmugham, Saravanan; Bergallo Patrizio > Subject: RE: [Speechsc] message-length clarification > > Any takers? I'm with option 2, as that leaves things as it and is > workable. > > -----Original Message----- > From: Dave Burke [mailto:david.burke@voxpilot.com] > Sent: Monday, April 17, 2006 12:57 PM > To: Corby Anderson; Brett Gavagni > Cc: speechsc@ietf.org; Shanmugham, Saravanan; Bergallo Patrizio > Subject: Re: [Speechsc] message-length clarification > > In the interests of rough consensus: > > o Preference for: > - Remove message-length altogether > > o Can live with: > - Zero-padding note (as per Sarvi's suggestion) > > o Don't like: > - message-length doesn't include start-line > (because this is a half-way house with negligible value - the > parser will be searching for \n anyways so why not iterate up > to Content-Length) > > Dave > > ----- Original Message ----- > From: "Brett Gavagni" <gavagni@us.ibm.com> > To: "Corby Anderson" <corby@tellme.com> > Cc: <speechsc@ietf.org>; "Shanmugham, Saravanan" <sarvi@cisco.com>; > "Bergallo Patrizio" <patrizio.bergallo@loquendo.com> > Sent: Monday, April 17, 2006 3:42 PM > Subject: Re: [Speechsc] message-length clarification > > > > That was the original suggestion when I started with this thread > > > (http://www1.ietf.org/mail-archive/web/speechsc/current/msg01722.html), > > and this suggestion wasn't too well received. > > > > "Propose to modify the wording that message-length does NOT include > the > > start-line as an issue to track for the next draft." > > > > So then we diverged into the defining the true value of the > message-length > > token, and thus the proposal for the removal of the message-length > token > > in its entirety. > > > > This removal proposal was fueled even more with the distinction that > the > > MRCPv2 session control is separated, especially since MRCPv2 messages > are > > NOT expected/described as tunnelled. > > > > I'd be happy if the message-length was modified as originally proposed > to > > NOT include the size of the start-line in the length, or if the > > message-length to be removed from the draft. > > > > IMO, anything else is a hack. =) > > > > Continue the flame roasting as necessary. =) > > > > Thanks, > > > > Brett Gavagni > > WebSphere Voice Server Development > > http://www-306.ibm.com/software/pervasive/voice_server/ > > gavagni@us.ibm.com > > > > > > > > > > Corby Anderson <corby@tellme.com> > > 04/14/2006 08:26 PM > > > > To > > Brett Gavagni/West Palm Beach/IBM@IBMUS > > cc > > "Shanmugham, Saravanan" <sarvi@cisco.com>, speechsc@ietf.org, Bergallo > > Patrizio <patrizio.bergallo@loquendo.com> > > Subject > > Re: [Speechsc] message-length clarification > > > > > > > > > > > > > > No, you're not the only one. :-) It is hacky. The size calculation > that > > Dave Burke posted is concise, but it's cumbersome. > > > > But stepping back a little, it *is* helpful to know the size ahead of > > time. Since clients can share an MRCP control channel, it's makes the > > server's job easier if it knows ahead of time how many bytes will be > in a > > particular command. You can imagine an implementation where a the > socket > > reader understands the first-line format enough to read all the bytes > for > > a single message into a buffer and then hand it off to a different > > class/function/thread for further processing. > > > > How about if the length pertained to the size of everything *except* > the > > first line? That would make the size calculation trivial and would > still > > offer the benefit of having the size around for parsing purposes. > > > > Corby Anderson > > Tellme Networks > > > > Brett Gavagni wrote: > > Am I the only one that thinks this suggestion for padding a fixed > length > > is a Band-Aid (*hack) for the real problem identified by this thread? > > > > Thanks, > > > > Brett Gavagni > > WebSphere Voice Server Development > > http://www-306.ibm.com/software/pervasive/voice_server/ > > gavagni@us.ibm.com > > > > > > > > > > "Shanmugham, Saravanan" <sarvi@cisco.com> > > 04/14/2006 02:06 PM > > > > To > > "Bergallo Patrizio" <patrizio.bergallo@loquendo.com>, > <speechsc@ietf.org> > > cc > > > > Subject > > RE: [Speechsc] message-length clarification > > > > > > > > > > > > > > Pete/Bergallo, > > > > Leading spaces are illegal per the current ABNF definition. > > But Pete's suggestion is perfectly legal and makes the encoding phase > just > > > > as effciient. > > > > I can add this clarification/suggestion for implementers into the > > specification. > > > > Thx, > > > > Sarvi > > > > From: Bergallo Patrizio [mailto:patrizio.bergallo@loquendo.com] > > Sent: Friday, April 14, 2006 1:44 AM > > To: speechsc@ietf.org > > Subject: RE: [Speechsc] message-length clarification > > > > > > I agree that problems arise more on encoding side than in decoding > one. > > What about using leading SP, with the same purpose of leading zeros > > mentioned by Pete? > > Is it legal? > > Anyway, though I'm not a big fan of message-length field, I think that > > removing it at this stage of spec should be avoided. > > > > Regards, > > Patrizio Bergallo, Loquendo. > > > > > > -----Original Message----- > > From: Pete Cordell [mailto:pete@tech-know-ware.com] > > Sent: Friday, April 14, 2006 9:55 AM > > To: Dave Burke > > Cc: speechsc@ietf.org > > Subject: Re: [Speechsc] message-length clarification > > > > > > As someone watching from the sidelines, this issue about the > > representation > > of the length field potentially changing the value of the > > length that needed > > to be encoded occurred to me also. > > > > I wondered if you could use leading zeros in the length field > > so that it is > > always fixed length. e.g. in C it would be something like: > > > > sprintf( lstr, "%04d", len ); // Not sure if 4 is the right number! > > > > Messages would then look like: > > > > MRCP/2.0 0047 543256 200 COMPLETE > > ... > > > > Still a bit of a gotcha though, that could lead to one of > > those one in a > > hundred type bugs! > > > > Regards, > > > > Pete. > > -- > > ============================================= > > Pete Cordell > > Tech-Know-Ware Ltd > > for XML to C++ data binding visit > > http://www.tech-know-ware.com/lmx > > (or http://www.xml2cpp.com) > > ============================================= > > > > ----- Original Message ----- > > From: "Dave Burke" > > To: "Shanmugham, Saravanan" ; "Brett Gavagni" > > > > Cc: > > Sent: Friday, April 14, 2006 12:39 AM > > Subject: Re: [Speechsc] message-length clarification > > > > > > > > Just wanted to insert one point that I haven't seen mentioned: The > > message-length makes it easier to decode but not encode. > > > > This is because the message-length also includes the number > > > > of bytes > > > > that > > specify the message-length in the header. The algorithm for > > > > determining > > > > the message-length has to add up all the bytes in the > > > > message to get a > > > > total (label: N), then determine the number of bytes to represent N > > (label: M), then check if the total N+M rolls over a power > > > > of 10 (if it > > > > does you need another byte). The value to insert for the > > > > message-length is > > > > not simply N+M but rather > > > > (N >= (10^M-M)) ? N+M+1 : N+M > > > > For example, if N=97 then M=2 and N+M=99=message-length. > > > > However, if > > > > N=98 > > then M=2 but now N+M=100 => message-length=N+M+1 > > > > Sorta awkward - no? > > > > Dave > > > > > > > > > > > > ----- Original Message ----- > > From: "Brett Gavagni" > > To: "Shanmugham, Saravanan" > > Cc: > > Sent: Thursday, April 13, 2006 1:52 PM > > Subject: RE: [Speechsc] message-length clarification > > > > > > Hi Sarvi, > > > > I realize that it may be late in the game for addressing > > > > problems in > > > > the specification, but I would evangelize that its cheaper > > > > to pay now > > > > (potential standardization delays) than to pay later (poor > > > > adoption) > > > > due to convolution and problematic issues in the spec. > > > > Since the session control for MRCPv2 is separated (a la SIP, RTSP, > > etc..) and not tunnelled, what would be the compelling > > > > reason that the > > > > message-length token exist in the start-line especially since the > > "Content-Length" header? > > > > I'm now proposing the removal of the message-length token from the > > start-line in entirety, as it is at least redundant and > > > > deviating from > > > > the HTTP-like conventions leveraged throughout the spec. > > > > Thanks, > > > > Brett Gavagni > > WebSphere Voice Server Development > > http://www-306.ibm.com/software/pervasive/voice_server/ > > gavagni@us.ibm.com > > > > > > ...cut... > > > > > > > > _______________________________________________ > > Speechsc mailing list > > Speechsc@ietf.org https://www1.ietf.org/mailman/listinfo/speechsc > > > > > > > > Gruppo Telecom Italia - Direzione e coordinamento di Telecom Italia > S.p.A. > > > > ================================================ > > CONFIDENTIALITY NOTICE > > This message and its attachments are addressed solely to the persons > > above and may contain confidential information. If you have received > > the message in error, be informed that any use of the content hereof > > is prohibited. Please return it immediately to the sender and delete > > the message. Should you have any questions, please send an e_mail to > > <mailto:webmaster@telecomitalia.it>webmaster@telecomitalia.it. Thank > you > > <http://www.loquendo.com>www.loquendo.com > > ================================================ > > _______________________________________________ > > Speechsc mailing list > > Speechsc@ietf.org > > https://www1.ietf.org/mailman/listinfo/speechsc > > > > > > > > _______________________________________________ > > Speechsc mailing list > > Speechsc@ietf.org > > https://www1.ietf.org/mailman/listinfo/speechsc > > > > > > > > _______________________________________________ > > Speechsc mailing list > > Speechsc@ietf.org > > https://www1.ietf.org/mailman/listinfo/speechsc > > > > > _______________________________________________ > Speechsc mailing list > Speechsc@ietf.org > https://www1.ietf.org/mailman/listinfo/speechsc > > _______________________________________________ > Speechsc mailing list > Speechsc@ietf.org > https://www1.ietf.org/mailman/listinfo/speechsc _______________________________________________ Speechsc mailing list Speechsc@ietf.org https://www1.ietf.org/mailman/listinfo/speechsc
- [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Carter, Jerry
- RE: [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Shanmugham, Saravanan
- RE: [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Shanmugham, Saravanan
- RE: [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Shanmugham, Saravanan
- RE: [Speechsc] message-length clarification Brett Gavagni
- Re: [Speechsc] message-length clarification Dave Burke
- RE: [Speechsc] message-length clarification Carter, Jerry
- Re: [Speechsc] message-length clarification Pete Cordell
- RE: [Speechsc] message-length clarification Bergallo Patrizio
- RE: [Speechsc] message-length clarification Shanmugham, Saravanan
- RE: [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Shanmugham, Saravanan
- RE: [Speechsc] message-length clarification Brett Gavagni
- Re: [Speechsc] message-length clarification Corby Anderson
- Re: [Speechsc] message-length clarification Brett Gavagni
- Re: [Speechsc] message-length clarification Dave Burke
- RE: [Speechsc] message-length clarification Burger, Eric
- RE: [Speechsc] message-length clarification Brett Gavagni
- RE: [Speechsc] message-length clarification Carter, Jerry
- RE: [Speechsc] message-length clarification Reifenrath, Klaus, VF-Group
- Re: [Speechsc] message-length clarification Dan Burnett