Re: H.248-controlled T.38 configurations: SDP- vs Property-based H.248 signalling
"Schwarz, Albrecht (Albrecht)" <[email protected]> Fri, 3 Aug 2012 11:09:47 +0200
| Newsgroups | gmane.ietf.megaco |
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| Message-ID | <5F7BCCF5541B7444830A2288ABBEBC96218B57EDCD@FRMRSSXCHMBSD2.dc-m.alcatel-lucent.com> |
--===============3520707778224723348== Content-Language: en-US Content-Type: multipart/alternative; boundary="_000_5F7BCCF5541B7444830A2288ABBEBC96218B57EDCDFRMRSSXCHMBSD_" --_000_5F7BCCF5541B7444830A2288ABBEBC96218B57EDCDFRMRSSXCHMBSD_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable With below indicated changes, we recommended the default settings for those= T.38 parameters, which is FALSE (i.e., 3GPP profiles would then recommend = NOT to use such T.38 configurations). Clause X.2 provides a RECOMMENDATION on T.38 configuration(s). Clause X.3 the correspondent negotiation procedures. I think that the prescriptive language between both clauses must be consist= ent (which isn't yet entirely the case in my opinion). E.g., Table X.3.1: T38FaxTranscodingJBIG Accept offer with value "FALSE" or parameter omitted. Otherwise reject offe= r (NOTE 3). Do not include parameter in the answer. (NOTE 2) =F0 Instead of "Otherwise reject offer (NOTE 3)." we should rather specify "Otherwise, offer SHOULD be rejected (NOTE x)" and NOTE x - This parameter is not recommended to use, but there might be remot= e T.38 endpoints with support of that capability. In order to improve the p= robability of a final successful T.38 call, the remote T.38 endpoint should= be indicated not to use this T.38 capability (see ANSWER). A pure rejection of the OFFER would immediately lead to an unsuccessful T. = 38 call. /Albrecht From: Belling, Thomas (NSN - DE/Munich) [mailto:[email protected]] Sent: Freitag, 3. August 2012 10:46 To: Schwarz, Albrecht (Albrecht); [email protected] Subject: RE: H.248-controlled T.38 configurations: SDP- vs Property-based H= .248 signalling Dear Albrecht, my proposal is still not include FAX "transcoding" in the 3GPP profile. Is = that acceptable to you? Thomas From: ext Schwarz, Albrecht (Albrecht) [mailto:albrecht.schwarz@alcatel-luc= ent.com] Sent: Friday, August 03, 2012 10:25 AM To: Belling, Thomas (NSN - DE/Munich); [email protected] Cc: [email protected] Subject: RE: H.248-controlled T.38 configurations: SDP- vs Property-based H= .248 signalling Hello Thomas, looks like that we are now on the same page, i.e. if the T.38 endpoint (her= e IM-MGW) would support that capability, then it could be also used in the = negotiation of T.38 configurations with the remote T.38 endpoint. Hence, the T.38 parameters are not related to remote G3FEs. There would be then following changes in your CRs, let's take Table X.2.1 a= s example: Table X.2.1: Recommended configuration for T.38 SDP attribute values. T38FaxVersion Version 2 or higher. (NOTE 1) T38MaxBitRate 14 400 T38FaxFillBitRemoval FALSE (NOTE 2) T38FaxTranscodingMMR FALSE (NOTE 2) T38FaxTranscodingJBIG FALSE (NOTE 2) T38FaxRateManagement 'transferredTCF' T38FaxMaxBuffer 1800 T38FaxMaxDatagram At least 150 T38FaxMaxIFP 40 (NOTE 3) T38FaxUdpEC 't38UDPRedundancy' T38FaxUdpECDepth Minred: 1; Maxred: 2 (NOTE 3) T38FaxUdpFECMaxSpan 3 (NOTE 3) T38ModemType 't38G3FaxOnly' (NOTE 2, NOTE 3) NOTE 1: With Version 4, default values for the SDP attributes apply if t= he attributes are omitted. However, some values relate to capabilities of t= he remote CS FAX equipment unknown to the MGCF. NOTE 2: This value relates to capabilities of the remote CS FAX equipmen= t unknown to the MGCF. The recommended value (which is also the default val= ue in T.38 version 4) is likely to be supported by FAX equipment in CS netw= orks. NOTE 3: Only applicable for T.38 version 4. Would you agree? Albrecht From: Belling, Thomas (NSN - DE/Munich) [mailto:[email protected]] Sent: Donnerstag, 2. August 2012 11:03 To: Schwarz, Albrecht (Albrecht); [email protected]<mailto:3GPP= [email protected]> Subject: RE: H.248-controlled T.38 configurations: SDP- vs Property-based H= .248 signalling Hello Albrecht, a gateway could support FAX "transcoding", as I like to call it, and then u= se those parameters. But as Kevin wrote, it is highly unusual for MGW imple= mentations to do so. In my view we should not burden the MGW with such func= tionality and the benefit is also questionable, in particular because Kevin= believes the JBIG and NMR encoding are also rarely used by T.38 terminals.= I was rather envisioning a reframing of T.30 at the MGW. Reading your expl= anation that you support the default values I suspect this is also what you= r MGW does (as mine). Also in the table B.1 you attached those parameters a= re "optional". So, depending on MGW implementation, those could either be c= apabilities of the CS FAX equipment (if a reframing is done at the MGW as I= envision), or of the MGW (if the MGW performs FAX "transcoding"). For the 3GPP profiles, we do not necesarrily include any conceivable option= but only options with a real benefit. I would prefer not to include FAX "t= ranscoding" for the reasons outlined above. Assuming that we only want to u= se the default value, it does not need to be signalled to the MGW but can r= ather be a provisioned value. So I do not see a need to propagate those par= ameters over the Mn interface. Perhaps the NOTES should be phrased a bit clearer and include an explanatio= n that only T.30 reframing is included in the Mn profile and under this con= dition, those SDP attributes relate to capabilities of the CS FAX equipment= . Thomas From: 3GPP_TSG_CT_WG3 - Core Network and Terminals WG 3 [mailto:3GPP_TSG_CT= [email protected]] On Behalf Of ext Schwarz, Albrecht (Albrecht) Sent: Thursday, August 02, 2012 10:05 AM To: [email protected]<mailto:[email protected]> Subject: Re: H.248-controlled T.38 configurations: SDP- vs Property-based H= .248 signalling Hello Thomas, I followed the SIP Forum FoIP thread, but I fail to see that confirmation t= owards remote G3FE. Actually it's rather the opposite, see Kevin's reply to you: > (I did not find any definition of MMR format apart from "Modified > Modified Read" in T.38. However on Annex VI of T.30, MMR is defined as > the T.6 encoding. This also matches explanations in Wikipedia) > > *T38FaxTranscodingJBIG*: Indicates the ability to convert to/from JBIG > to reduce bandwidth. This > > is a boolean parameter (inclusion =3D true, exclusion =3D false). It is possible for a T.30<->T.38 gateway to provide these behaviors if desi= red, and the resulting T.38 bitstream would differ in some noticeable ways = from the T.30 bitstream. However, based on discussions with various knowled= geable parties during our previous work in this group, it appears that it i= s highly unusual for a T.38 implementation (gateway or terminal) to actuall= y perform any of these three functions. =F0 it's a gateway capability! =F0 all your three referred T.38 parameters are subject of the IM-MGW impl= ementation! and ALU supports the recommended default values by Table H.2/T.38 (which sh= ould be inline with your proposal). Hence, Kevin explicitly confirms this also as gateway capability! Regards, Albrecht From: Belling, Thomas (NSN - DE/Munich) [mailto:[email protected]] Sent: Mittwoch, 1. August 2012 16:46 To: Schwarz, Albrecht (Albrecht); [email protected]<mailto:3GPP= [email protected]> Subject: RE: H.248-controlled T.38 configurations: SDP- vs Property-based H= .248 signalling Dear Albrecht, Thanks for your comments. with respect to T38FaxFillBitRemoval, T38FaxTranscodingMMR and T38FaxTransc= odingJBIG SDP attributes, to which Notes 1 and 2 relate, I had some discus= sions at the SIP forum FoIP mailing list as you suggested. And it was confirmed that unless you do some "transcoding" of the payload w= ithin T.38 at the MGW, those properties relate to the remote CS FAX endpoin= t. However, people thought that not signaling those properties in H.248v4 m= ight be OK, because the default values which then apply are likely to be su= pported by any receiving CS endpoint. The only open issue where I did not y= et receive any reply is whether any harm is done if the CS endpoint behaves= differently when sending. Thomas From: 3GPP_TSG_CT_WG3 - Core Network and Terminals WG 3 [mailto:3GPP_TSG_CT= [email protected]] On Behalf Of ext Schwarz, Albrecht (Albrecht) Sent: Wednesday, August 01, 2012 4:17 PM To: [email protected]<mailto:[email protected]> Subject: H.248-controlled T.38 configurations: SDP- vs Property-based H.248= signalling [Cc'd megaco list due to H.248.2] The T.38 parameters as defined by ITU-T T.38 are related to a T.38 endpoint= implementation, such as the T.38 user plane interworking function as e.g. = located in an H.248 IP-to-TDM media gateway (e.g. 3GPP IM-MGW). There are fundamentally two signaling options for such T.38 configurations: 1. SDP-based: using T.38 Annex D defined SDP elements embedded in H.248 d= escriptors 2. Property-based: using H.248.2, IP Fax package defined properties, such= as specified by clauses 10.1.3 to 10.1.7 Both H.248 signalling options are basically equivalent, - independent of SD= P- or Property-based signaling elements. The signaling elements relate to t= he T.38 endpoint, but NOT to any remote G3FE. [Note: the H.248 IP fax package version 1 (from 2005/2007) does not yet con= tain the latest T.38V4 (2010) parameter. But this aspect is irrelevant in t= his discussion due to the proposal in 3GPP for the SDP-based method.] Thus, all "T.38 SDP attributes" (in C3-121327) are related to gateway capabilitie= s (such as supported T.38 configurations by an IM-MGW implementation) (NOTE= : attached is T.38 Table B.1 for H.323 gateways, which again underlines the= relation to gateway capabilities). The MGC / MGCF may be either 1. aware of the supported T.38 configuration(s) by his associated MGs or 2. unaware. Awareness may be achieved via auditing or configuration management. Unawareness is basically possible, but may lead to inefficient or even inef= fective H.248 scenarios for T.38. Dependent on the amount of "supported T.38 configuration(s)" knowledge at M= GC level would be the content of the SIP-level SDP O/A procedures. Conclusions for C3-121327 (http://www.3gpp.org/ftp/tsg_ct/WG3_interworking_= ex-CN3/TSGC3_70_Chicago/Docs/C3-121327.zip): NOTEs 1 and 2 in Table X.3.1 are incorrect in my opinion. The text related to "remote CS FAX equipment" (term should be anyway replac= ed by term G3FE) should be just deleted. And there would be correspondent c= hanges at other tables. -Albrecht --_000_5F7BCCF5541B7444830A2288ABBEBC96218B57EDCDFRMRSSXCHMBSD_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <html xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-micr= osoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" = xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http:= //www.w3.org/TR/REC-html40"><head><meta http-equiv=3DContent-Type content= =3D"text/html; charset=3Diso-8859-1"><meta name=3DGenerator content=3D"Micr= osoft Word 12 (filtered medium)"><style><!-- /* Font Definitions */ @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0;} @font-face {font-family:Wingdings; panose-1:5 0 0 0 0 0 0 0 0 0;} @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} @font-face {font-family:Tahoma; panose-1:2 11 6 4 3 5 4 4 2 4;} @font-face {font-family:"CG Times \(WN\)"; panose-1:0 0 0 0 0 0 0 0 0 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0cm; 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mso-list-template-ids:1630049504;} @list l5:level1 {mso-level-number-format:alpha-lower; mso-level-tab-stop:36.0pt; mso-level-number-position:left; text-indent:-18.0pt;} ol {margin-bottom:0cm;} ul {margin-bottom:0cm;} --></style><!--[if gte mso 9]><xml> <o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext=3D"edit"> <o:idmap v:ext=3D"edit" data=3D"1" /> </o:shapelayout></xml><![endif]--></head><body lang=3DDE link=3Dblue vlink= =3Dpurple><div class=3DWordSection1><p class=3DMsoNormal><span lang=3DEN-US= style=3D'font-size:10.0pt;font-family:"Courier New";color:black'>With belo= w indicated changes, we recommended the default settings for those T.38 par= ameters, which is FALSE (i.e., 3GPP profiles would then <b>recommend</b> NO= T to use such T.38 configurations).<o:p></o:p></span></p><p class=3DMsoNorm= al><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";c= olor:black'><o:p> </o:p></span></p><p class=3DMsoNormal><span lang=3DE= N-US style=3D'font-size:10.0pt;font-family:"Courier New";color:black'>Claus= e X.2 provides a RECOMMENDATION on T.38 configuration(s).<o:p></o:p></span>= </p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-= family:"Courier New";color:black'>Clause X.3 the correspondent negotiation = procedures.<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US st= yle=3D'font-size:10.0pt;font-family:"Courier New";color:black'><o:p> <= /o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:= 10.0pt;font-family:"Courier New";color:black'>I think that the prescriptive= language between both clauses must be consistent (which isn’t yet en= tirely the case in my opinion).<o:p></o:p></span></p><p class=3DMsoNormal><= span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color= :black'><o:p> </o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US= style=3D'font-size:10.0pt;font-family:"Courier New";color:black'>E.g., Tab= le X.3.1:<o:p></o:p></span></p><div align=3Dcenter><table class=3DMsoNormal= Table border=3D1 cellspacing=3D0 cellpadding=3D0 width=3D643 style=3D'margi= n-left:-9.0cm;border-collapse:collapse;border:none'><tr><td width=3D170 val= ign=3Dtop style=3D'width:127.65pt;border:solid windowtext 1.5pt;border-righ= t:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b>T38= FaxTranscodingJBIG</b><b><span lang=3DEN-GB><o:p></o:p></span></b></p></td>= <td width=3D246 valign=3Dtop style=3D'width:184.3pt;border-top:solid window= text 1.5pt;border-left:none;border-bottom:solid windowtext 1.5pt;border-rig= ht:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span= lang=3DEN-US>Accept offer with value "FALSE" or parameter omitte= d. </span>Otherwise reject offer (NOTE 3). <span lang=3DEN-GB><o:p></o:p></= span></p></td><td width=3D227 valign=3Dtop style=3D'width:6.0cm;border:soli= d windowtext 1.5pt;border-left:none;padding:0cm 5.4pt 0cm 5.4pt'><p class= =3DTAL><span lang=3DEN-US>Do not include parameter in the answer. </span>(N= OTE 2)<span lang=3DEN-GB><o:p></o:p></span></p></td></tr></table></div><p c= lass=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"= Courier New";color:black'><o:p> </o:p></span></p><p class=3DMsoListPar= agraph style=3D'text-indent:-18.0pt;mso-list:l4 level1 lfo9'><![if !support= Lists]><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:Wingdings;c= olor:black'><span style=3D'mso-list:Ignore'>=F0<span style=3D'font:7.0pt "T= imes New Roman"'> </span></span></span><![endif]><span lang=3DEN-US s= tyle=3D'font-size:10.0pt;font-family:"Courier New";color:black'>Instead of = “</span><span lang=3DEN-US>Otherwise reject offer (NOTE 3).</span><sp= an lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color:b= lack'>” we should rather specify <br>“Otherwise, offer SHOULD b= e rejected (NOTE x)” and<o:p></o:p></span></p><p class=3DMsoListParag= raph><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New"= ;color:black'>NOTE x – This parameter is not recommended to use, but = there might be remote T.38 endpoints with support of that capability. In or= der to improve the probability of a final successful T.38 call, the remote = T.38 endpoint should be indicated not to use this T.38 capability (see ANSW= ER).<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'= font-size:10.0pt;font-family:"Courier New";color:black'><o:p> </o:p></= span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;= font-family:"Courier New";color:black'>A pure rejection of the OFFER would = immediately lead to an unsuccessful T. 38 call.<o:p></o:p></span></p><p cla= ss=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Co= urier New";color:black'><o:p> </o:p></span></p><p class=3DMsoNormal><s= pan lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color:= black'>/Albrecht<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-= US style=3D'font-size:10.0pt;font-family:"Courier New";color:olive'><o:p>&n= bsp;</o:p></span></p><div><div style=3D'border:none;border-top:solid #B5C4D= F 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DMsoNormal><b><span lang=3DEN-= US style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span= ></b><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahoma","san= s-serif"'> Belling, Thomas (NSN - DE/Munich) [mailto:[email protected]= ] <br><b>Sent:</b> Freitag, 3. August 2012 10:46<br><b>To:</b> Schwarz, Alb= recht (Albrecht); [email protected]<br><b>Subject:</b> RE: H.24= 8-controlled T.38 configurations: SDP- vs Property-based H.248 signalling<o= :p></o:p></span></p></div></div><p class=3DMsoNormal><o:p> </o:p></p><= p class=3DMsoNormal><span style=3D'font-size:11.0pt;font-family:"Calibri","= sans-serif";color:#1F497D'>Dear Albrecht,<o:p></o:p></span></p><p class=3DM= soNormal><span style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif"= ;color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal><span lang= =3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color= :#1F497D'>my proposal is still not include FAX “transcoding” in= the 3GPP profile. Is that acceptable to you?<o:p></o:p></span></p><p class= =3DMsoNormal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Cali= bri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMso= Normal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","= sans-serif";color:#1F497D'>Thomas<o:p></o:p></span></p><p class=3DMsoNormal= ><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-s= erif";color:#1F497D'><o:p> </o:p></span></p><div><div style=3D'border:= none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DM= soNormal><b><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahom= a","sans-serif"'>From:</span></b><span lang=3DEN-US style=3D'font-size:10.0= pt;font-family:"Tahoma","sans-serif"'> ext Schwarz, Albrecht (Albrecht) [ma= ilto:[email protected]] <br><b>Sent:</b> Friday, August 0= 3, 2012 10:25 AM<br><b>To:</b> Belling, Thomas (NSN - DE/Munich); 3GPP_TSG_= [email protected]<br><b>Cc:</b> [email protected]<br><b>Subject:</b> RE: H= .248-controlled T.38 configurations: SDP- vs Property-based H.248 signallin= g<o:p></o:p></span></p></div></div><p class=3DMsoNormal><o:p> </o:p></= p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-fa= mily:"Courier New";color:#003300'>Hello Thomas,<o:p></o:p></span></p><p cla= ss=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Co= urier New";color:#003300'>looks like that we are now on the same page, i.e.= if the T.38 endpoint (here IM-MGW) would support that capability, then it = could be also used in the negotiation of T.38 configurations with the remot= e T.38 endpoint.<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-= US style=3D'font-size:10.0pt;font-family:"Courier New";color:#003300'>Hence= , the T.38 parameters are not related to remote G3FEs.<o:p></o:p></span></p= ><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-fam= ily:"Courier New";color:#003300'>There would be then following changes in y= our CRs, let’s take Table X.2.1 as example:<o:p></o:p></span></p><p c= lass=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"= Courier New";color:#003300'><o:p> </o:p></span></p><p class=3DMsoNorma= l><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";co= lor:#003300'><o:p> </o:p></span></p><p class=3DTH><span lang=3DEN-GB>T= able <span style=3D'background:yellow;mso-highlight:yellow'>X</span>.2.1: R= ecommended configuration for T.38 SDP attribute values.<o:p></o:p></span></= p><div align=3Dcenter><table class=3DMsoNormalTable border=3D0 cellspacing= =3D0 cellpadding=3D0 width=3D638 style=3D'width:478.5pt;margin-left:-142.3p= t;border-collapse:collapse'><tr><td width=3D285 valign=3Dtop style=3D'width= :213.4pt;border-top:1.5pt;border-left:1.5pt;border-bottom:1.0pt;border-righ= t:1.0pt;border-color:windowtext;border-style:solid;padding:0cm 5.4pt 0cm 5.= 4pt'><p class=3DTAL><b><span lang=3DEN-GB>T38FaxVersion<o:p></o:p></span></= b></p></td><td width=3D354 valign=3Dtop style=3D'width:265.45pt;border-top:= solid windowtext 1.5pt;border-left:none;border-bottom:solid windowtext 1.0p= t;border-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class= =3DTAL><span lang=3DEN-GB>Version 2 or higher. (NOTE 1)<o:p></o:p></span></= p></td></tr><tr><td width=3D285 valign=3Dtop style=3D'width:213.4pt;border-= top:none;border-left:solid windowtext 1.5pt;border-bottom:solid windowtext = 1.0pt;border-right:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p c= lass=3DTAL><b><span lang=3DEN-GB>T38MaxBitRate<o:p></o:p></span></b></p></t= d><td width=3D354 valign=3Dtop style=3D'width:265.45pt;border-top:none;bord= er-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid window= text 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span lang=3DEN-GB>1= 4 400<span style=3D'color:black'><o:p></o:p></span></span></p></td></tr><tr= ><td width=3D285 valign=3Dtop style=3D'width:213.4pt;border-top:none;border= -left:solid windowtext 1.5pt;border-bottom:solid windowtext 1.0pt;border-ri= ght:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><= span lang=3DEN-GB>T38FaxFillBitRemoval<o:p></o:p></span></b></p></td><td wi= dth=3D354 valign=3Dtop style=3D'width:265.45pt;border-top:none;border-left:= none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.5= pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span lang=3DEN-GB>FALSE <s>= (NOTE 2)</s><o:p></o:p></span></p></td></tr><tr><td width=3D285 valign=3Dto= p style=3D'width:213.4pt;border-top:none;border-left:solid windowtext 1.5pt= ;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;p= adding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><span lang=3DEN-GB>T38FaxTran= scodingMMR<o:p></o:p></span></b></p></td><td width=3D354 valign=3Dtop style= =3D'width:265.45pt;border-top:none;border-left:none;border-bottom:solid win= dowtext 1.0pt;border-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4= pt'><p class=3DTAL><span lang=3DEN-GB>FALSE <s>(NOTE 2)</s><o:p></o:p></spa= n></p></td></tr><tr><td width=3D285 valign=3Dtop style=3D'width:213.4pt;bor= der-top:none;border-left:solid windowtext 1.5pt;border-bottom:solid windowt= ext 1.0pt;border-right:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'>= <p class=3DTAL><b><span lang=3DEN-GB>T38FaxTranscodingJBIG<o:p></o:p></span= ></b></p></td><td width=3D354 valign=3Dtop style=3D'width:265.45pt;border-t= op:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:= solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span la= ng=3DEN-GB>FALSE <s>(NOTE 2)</s><o:p></o:p></span></p></td></tr><tr><td wid= th=3D285 valign=3Dtop style=3D'width:213.4pt;border-top:none;border-left:so= lid windowtext 1.5pt;border-bottom:solid windowtext 1.0pt;border-right:soli= d windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><span lan= g=3DEN-GB>T38FaxRateManagement<o:p></o:p></span></b></p></td><td width=3D35= 4 valign=3Dtop style=3D'width:265.45pt;border-top:none;border-left:none;bor= der-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.5pt;paddi= ng:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span lang=3DEN-GB>'transferredTCF'<= o:p></o:p></span></p></td></tr><tr><td width=3D285 valign=3Dtop style=3D'wi= dth:213.4pt;border-top:none;border-left:solid windowtext 1.5pt;border-botto= m:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;padding:0cm 5.= 4pt 0cm 5.4pt'><p class=3DTAL><b><span lang=3DEN-GB>T38FaxMaxBuffer<o:p></o= :p></span></b></p></td><td width=3D354 valign=3Dtop style=3D'width:265.45pt= ;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;bord= er-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL= ><span lang=3DEN-GB>1800<span style=3D'color:black'><o:p></o:p></span></spa= n></p></td></tr><tr><td width=3D285 valign=3Dtop style=3D'width:213.4pt;bor= der-top:none;border-left:solid windowtext 1.5pt;border-bottom:solid windowt= ext 1.0pt;border-right:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'>= <p class=3DTAL><b><span lang=3DEN-GB>T38FaxMaxDatagram<o:p></o:p></span></b= ></p></td><td width=3D354 valign=3Dtop style=3D'width:265.45pt;border-top:n= one;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:soli= d windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span lang= =3DEN-GB>At least 150<o:p></o:p></span></p></td></tr><tr><td width=3D285 va= lign=3Dtop style=3D'width:213.4pt;border-top:none;border-left:solid windowt= ext 1.5pt;border-bottom:solid windowtext 1.0pt;border-right:solid windowtex= t 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><span lang=3DEN-GB>T= 38FaxMaxIFP<o:p></o:p></span></b></p></td><td width=3D354 valign=3Dtop styl= e=3D'width:265.45pt;border-top:none;border-left:none;border-bottom:solid wi= ndowtext 1.0pt;border-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.= 4pt'><p class=3DTAL><span lang=3DEN-GB>40 (NOTE 3)<o:p></o:p></span></p></t= d></tr><tr><td width=3D285 valign=3Dtop style=3D'width:213.4pt;border-top:n= one;border-left:solid windowtext 1.5pt;border-bottom:solid windowtext 1.0pt= ;border-right:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class= =3DTAL><b><span lang=3DEN-GB>T38FaxUdpEC<o:p></o:p></span></b></p></td><td = width=3D354 valign=3Dtop style=3D'width:265.45pt;border-top:none;border-lef= t:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1= .5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span lang=3DEN-GB>'t38UDP= Redundancy'<o:p></o:p></span></p></td></tr><tr><td width=3D285 valign=3Dtop= style=3D'width:213.4pt;border-top:none;border-left:solid windowtext 1.5pt;= border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;pa= dding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><span lang=3DEN-GB>T38FaxUdpEC= Depth<o:p></o:p></span></b></p></td><td width=3D354 valign=3Dtop style=3D'w= idth:265.45pt;border-top:none;border-left:none;border-bottom:solid windowte= xt 1.0pt;border-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><= p class=3DTAL><span lang=3DEN-GB>Minred: 1; Maxred: 2 (NOTE 3)<o:p></o:p></= span></p></td></tr><tr><td width=3D285 valign=3Dtop style=3D'width:213.4pt;= border-top:none;border-left:solid windowtext 1.5pt;border-bottom:solid wind= owtext 1.0pt;border-right:solid windowtext 1.0pt;padding:0cm 5.4pt 0cm 5.4p= t'><p class=3DTAL><b><span lang=3DEN-GB>T38FaxUdpFECMaxSpan<o:p></o:p></spa= n></b></p></td><td width=3D354 valign=3Dtop style=3D'width:265.45pt;border-= top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right= :solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><span l= ang=3DEN-GB>3 (NOTE 3)<o:p></o:p></span></p></td></tr><tr><td width=3D285 v= align=3Dtop style=3D'width:213.4pt;border-top:none;border-left:solid window= text 1.5pt;border-bottom:solid windowtext 1.5pt;border-right:solid windowte= xt 1.0pt;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAL><b><span lang=3DEN-GB>= T38ModemType<o:p></o:p></span></b></p></td><td width=3D354 valign=3Dtop sty= le=3D'width:265.45pt;border-top:none;border-left:none;border-bottom:solid w= indowtext 1.5pt;border-right:solid windowtext 1.5pt;padding:0cm 5.4pt 0cm 5= .4pt'><p class=3DTAL><span lang=3DEN-GB>'t38G3FaxOnly' (<s>NOTE 2,</s> NOTE= 3)<o:p></o:p></span></p></td></tr><tr><td width=3D638 colspan=3D2 valign= =3Dtop style=3D'width:478.85pt;border:solid windowtext 1.5pt;border-top:non= e;padding:0cm 5.4pt 0cm 5.4pt'><p class=3DTAN><span lang=3DEN-GB>NOTE 1:&nb= sp; With Version 4, default values for the SDP attributes apply= if the attributes are omitted. <s>However, some values relate to capabilit= ies of the remote CS FAX equipment unknown to the MGCF.</s><o:p></o:p></spa= n></p><p class=3DTAN><s><span lang=3DEN-GB>NOTE 2: This v= alue relates to capabilities of the remote CS FAX equipment unknown to the = MGCF. The recommended value (which is also the default value in T.38 versio= n 4) is likely to be supported by FAX equipment in CS networks.<o:p></o:p><= /span></s></p><p class=3DTAN><span lang=3DEN-GB>NOTE 3: Only a= pplicable for T.38 version 4.<o:p></o:p></span></p></td></tr></table></div>= <p class=3DMsoNormal><span lang=3DEN-GB style=3D'font-size:10.0pt'><o:p>&nb= sp;</o:p></span></p><p class=3DMsoNormal><span lang=3DEN-GB style=3D'font-s= ize:10.0pt;font-family:"Courier New";color:#003300'>Would you agree?<o:p></= o:p></span></p><p class=3DMsoNormal><span lang=3DEN-GB style=3D'font-size:1= 0.0pt;font-family:"Courier New";color:#003300'>Albrecht<o:p></o:p></span></= p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-fa= mily:"Courier New";color:#003300'><o:p> </o:p></span></p><p class=3DMs= oNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier N= ew";color:#003300'><o:p> </o:p></span></p><div><div style=3D'border:no= ne;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DMso= Normal><b><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahoma"= ,"sans-serif"'>From:</span></b><span lang=3DEN-US style=3D'font-size:10.0pt= ;font-family:"Tahoma","sans-serif"'> Belling, Thomas (NSN - DE/Munich) [<a = href=3D"mailto:[email protected]">mailto:[email protected]</a>] <= br><b>Sent:</b> Donnerstag, 2. August 2012 11:03<br><b>To:</b> Schwarz, Alb= recht (Albrecht); <a href=3D"mailto:[email protected]">3GPP_TSG= [email protected]</a><br><b>Subject:</b> RE: H.248-controlled T.38 conf= igurations: SDP- vs Property-based H.248 signalling<o:p></o:p></span></p></= div></div><p class=3DMsoNormal><o:p> </o:p></p><p class=3DMsoNormal><s= pan lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-seri= f";color:#1F497D'>Hello Albrecht,<o:p></o:p></span></p><p class=3DMsoNormal= ><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-s= erif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal><span= lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";= color:#1F497D'>a gateway could support FAX “transcoding”, as I = like to call it, and then use those parameters. But as Kevin wrote, it is h= ighly unusual for MGW implementations to do so. In my view we should not bu= rden the MGW with such functionality and the benefit is also questionable, = in particular because Kevin believes the JBIG and NMR encoding are also rar= ely used by T.38 terminals. I was rather envisioning a reframing of T.30 at= the MGW. Reading your explanation that you support the default values I su= spect this is also what your MGW does (as mine). Also in the table B.1 you = attached those parameters are “optional”. So, depending on MGW = implementation, those could either be capabilities of the CS FAX equipment = (if a reframing is done at the MGW as I envision), or of the MGW (if the MG= W performs FAX “transcoding”).<o:p></o:p></span></p><p class=3D= MsoNormal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri= ","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNor= mal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","san= s-serif";color:#1F497D'>For the 3GPP profiles, we do not necesarrily includ= e any conceivable option but only options with a real benefit. I would pref= er not to include FAX “transcoding” for the reasons outlined ab= ove. Assuming that we only want to use the default value, it does not need = to be signalled to the MGW but can rather be a provisioned value. So I do n= ot see a need to propagate those parameters over the Mn interface.<o:p></o:= p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:11.= 0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></sp= an></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:11.0pt;fo= nt-family:"Calibri","sans-serif";color:#1F497D'>Perhaps the NOTES should be= phrased a bit clearer and include an explanation that only T.30 reframing = is included in the Mn profile and under this condition, those SDP attribute= s relate to capabilities of the CS FAX equipment.<o:p></o:p></span></p><p c= lass=3DMsoNormal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"= Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class= =3DMsoNormal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Cali= bri","sans-serif";color:#1F497D'>Thomas<o:p></o:p></span></p><p class=3DMso= Normal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","= sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal= ><span style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#= 1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal><span style=3D'fon= t-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> = </o:p></span></p><div><div style=3D'border:none;border-top:solid #B5C4DF 1.= 0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DMsoNormal><b><span lang=3DEN-US s= tyle=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b= ><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahoma","sans-se= rif"'> 3GPP_TSG_CT_WG3 - Core Network and Terminals WG 3 [<a href=3D"mailto= :[email protected]">mailto:[email protected]</a>] <= b>On Behalf Of </b>ext Schwarz, Albrecht (Albrecht)<br><b>Sent:</b> Thursda= y, August 02, 2012 10:05 AM<br><b>To:</b> <a href=3D"mailto:3GPP_TSG_CT_WG3= @LIST.ETSI.ORG">[email protected]</a><br><b>Subject:</b> Re: H.= 248-controlled T.38 configurations: SDP- vs Property-based H.248 signalling= <o:p></o:p></span></p></div></div><p class=3DMsoNormal><o:p> </o:p></p= ><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-fam= ily:"Courier New";color:#993366'>Hello Thomas,<o:p></o:p></span></p><p clas= s=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Cou= rier New";color:#993366'><o:p> </o:p></span></p><p class=3DMsoNormal><= span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color= :#993366'>I followed the SIP Forum FoIP thread, but I fail to see that conf= irmation towards remote G3FE.<o:p></o:p></span></p><p class=3DMsoNormal><sp= an lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color:#= 993366'>Actually it’s rather the opposite, see Kevin’s reply to= you:<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D= 'font-size:10.0pt;font-family:"Courier New";color:#993366'><o:p> </o:p= ></span></p><p class=3DMsoPlainText><span lang=3DEN-US>> (I did not find= any definition of MMR format apart from “Modified <o:p></o:p></span>= </p><p class=3DMsoPlainText><span lang=3DEN-US>> Modified Read” in= T.38. However on Annex VI of T.30, MMR is defined as <o:p></o:p></span></p= ><p class=3DMsoPlainText><span lang=3DEN-US>> the T.6 encoding. This als= o matches explanations in Wikipedia)<o:p></o:p></span></p><p class=3DMsoPla= inText><span lang=3DEN-US>><o:p> </o:p></span></p><p class=3DMsoPla= inText><span lang=3DEN-US>> *T38FaxTranscodingJBIG*: Indicates the abili= ty to convert to/from JBIG <o:p></o:p></span></p><p class=3DMsoPlainText><s= pan lang=3DEN-US>> to reduce bandwidth. This<o:p></o:p></span></p><p cla= ss=3DMsoPlainText><span lang=3DEN-US>><o:p> </o:p></span></p><p cla= ss=3DMsoPlainText><span lang=3DEN-US>> is a boolean parameter (inclusion= =3D true, exclusion =3D false).<o:p></o:p></span></p><p class=3DMsoPlainTe= xt><span lang=3DEN-US><o:p> </o:p></span></p><p class=3DMsoPlainText><= span lang=3DEN-US>It is <span style=3D'color:red'>possible for a T.30<-&= gt;T.38 gateway</span> to <span style=3D'color:red'>provide these behaviors= if desired</span>, and the resulting T.38 bitstream would differ in some n= oticeable ways from the T.30 bitstream. However, based on discussions with = various knowledgeable parties during our previous work in this group, it ap= pears that it is highly unusual for a T.38 implementation (gateway or termi= nal) to actually perform any of these three functions.<o:p></o:p></span></p= ><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;font-fam= ily:"Courier New";color:#993366'><o:p> </o:p></span></p><p class=3DMso= Normal><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier Ne= w";color:#993366'><o:p> </o:p></span></p><p class=3DMsoListParagraph s= tyle=3D'text-indent:-18.0pt;mso-list:l1 level1 lfo2'><![if !supportLists]><= span lang=3DEN-US style=3D'font-size:10.0pt;font-family:Wingdings;color:#99= 3366'><span style=3D'mso-list:Ignore'>=F0<span style=3D'font:7.0pt "Times N= ew Roman"'> </span></span></span><![endif]><span lang=3DEN-US style= =3D'font-size:10.0pt;font-family:"Courier New";color:#993366'>it’s a = gateway capability!<o:p></o:p></span></p><p class=3DMsoListParagraph style= =3D'text-indent:-18.0pt;mso-list:l1 level1 lfo2'><![if !supportLists]><span= lang=3DEN-US style=3D'font-size:10.0pt;font-family:Wingdings;color:#993366= '><span style=3D'mso-list:Ignore'>=F0<span style=3D'font:7.0pt "Times New R= oman"'> </span></span></span><![endif]><span lang=3DEN-US style=3D'fo= nt-size:10.0pt;font-family:"Courier New";color:#993366'>all your three refe= rred T.38 parameters are subject of the IM-MGW implementation!<o:p></o:p></= span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;= font-family:"Courier New";color:#993366'>and ALU supports the recommended d= efault values by Table H.2/T.38 (which should be inline with your proposal)= .<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'fon= t-size:10.0pt;font-family:"Courier New";color:#993366'><o:p> </o:p></s= pan></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'font-size:10.0pt;f= ont-family:"Courier New";color:#993366'>Hence, Kevin explicitly confirms th= is also as gateway capability!<o:p></o:p></span></p><p class=3DMsoNormal><s= pan lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Courier New";color:= #993366'><o:p> </o:p></span></p><p class=3DMsoNormal><span lang=3DEN-U= S style=3D'font-size:10.0pt;font-family:"Courier New";color:#993366'>Regard= s,<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'fo= nt-size:10.0pt;font-family:"Courier New";color:#993366'>Albrecht<o:p></o:p>= </span></p><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family= :"Courier New";color:#993366'><o:p> </o:p></span></p><p class=3DMsoNor= mal><span style=3D'font-size:10.0pt;font-family:"Courier New";color:#993366= '><o:p> </o:p></span></p><p class=3DMsoNormal><span style=3D'font-size= :10.0pt;font-family:"Courier New";color:#993366'><o:p> </o:p></span></= p><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courier= New";color:#993366'><o:p> </o:p></span></p><div><div style=3D'border:= none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DM= soNormal><b><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahom= a","sans-serif"'>From:</span></b><span lang=3DEN-US style=3D'font-size:10.0= pt;font-family:"Tahoma","sans-serif"'> Belling, Thomas (NSN - DE/Munich) [<= a href=3D"mailto:[email protected]">mailto:[email protected]</a>]= <br><b>Sent:</b> Mittwoch, 1. August 2012 16:46<br><b>To:</b> Schwarz, Alb= recht (Albrecht); <a href=3D"mailto:[email protected]">3GPP_TSG= [email protected]</a><br><b>Subject:</b> RE: H.248-controlled T.38 conf= igurations: SDP- vs Property-based H.248 signalling<o:p></o:p></span></p></= div></div><p class=3DMsoNormal><o:p> </o:p></p><p class=3DMsoNormal><s= pan lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-seri= f";color:#1F497D'>Dear Albrecht,<o:p></o:p></span></p><p class=3DMsoNormal>= <span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-se= rif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal><span = lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";c= olor:#1F497D'>Thanks for your comments.<o:p></o:p></span></p><p class=3DMso= Normal><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","= sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal= ><span lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-s= erif";color:#1F497D'>with respect to T38FaxFillBitRemoval, T38FaxTranscodin= gMMR and T38FaxTranscodingJBIG SDP attributes, to which Notes 1 and 2 relat= e, I had some discussions at the SIP forum FoIP mailing list as you s= uggested.<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US styl= e=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:= p> </o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D'f= ont-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>And it wa= s confirmed that unless you do some “transcoding” of the payloa= d within T.38 at the MGW, those properties relate to the remote CS FAX endp= oint. However, people thought that not signaling those properties in H.248v= 4 might be OK, because the default values which then apply are likely to be= supported by any receiving CS endpoint. The only open issue where I did no= t yet receive any reply is whether any harm is done if the CS endpoint beha= ves differently when sending.<o:p></o:p></span></p><p class=3DMsoNormal><sp= an lang=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif= ";color:#1F497D'><o:p> </o:p></span></p><p class=3DMsoNormal><span lan= g=3DEN-US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";colo= r:#1F497D'>Thomas<o:p></o:p></span></p><p class=3DMsoNormal><span lang=3DEN= -US style=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F4= 97D'><o:p> </o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US st= yle=3D'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><= o:p> </o:p></span></p><p class=3DMsoNormal><span lang=3DEN-US style=3D= 'font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p>&n= bsp;</o:p></span></p><div><div style=3D'border:none;border-top:solid #B5C4D= F 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=3DMsoNormal><b><span lang=3DEN-= US style=3D'font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span= ></b><span lang=3DEN-US style=3D'font-size:10.0pt;font-family:"Tahoma","san= s-serif"'> 3GPP_TSG_CT_WG3 - Core Network and Terminals WG 3 [<a href=3D"ma= ilto:[email protected]">mailto:[email protected]</a= >] <b>On Behalf Of </b>ext Schwarz, Albrecht (Albrecht)<br><b>Sent:</b> Wed= nesday, August 01, 2012 4:17 PM<br><b>To:</b> <a href=3D"mailto:3GPP_TSG_CT= [email protected]">[email protected]</a><br><b>Subject:</b> H.= 248-controlled T.38 configurations: SDP- vs Property-based H.248 signalling= <o:p></o:p></span></p></div></div><p class=3DMsoNormal><o:p> </o:p></p= ><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Cou= rier New";color:#002060'>[Cc’d megaco list due to H.248.2]</span><spa= n style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></= p></div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-fami= ly:"Courier New";color:#002060'> </span><span style=3D'font-size:10.0p= t;font-family:"Courier New"'><o:p></o:p></span></p></div><div><p class=3DMs= oNormal><span style=3D'font-size:10.0pt;font-family:"Courier New";color:#00= 2060'>The <b>T.38 parameters</b> as defined by ITU-T T.38 are related to a = <b>T.38 endpoint implementation</b>, such as the <b>T.38 user plane interwo= rking function</b> as e.g. located in an H.248 IP-to-TDM media gateway (e.g= . 3GPP IM-MGW).</span><span style=3D'font-size:10.0pt;font-family:"Courier = New"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span style=3D'= font-size:10.0pt;font-family:"Courier New";color:#002060'> </span><spa= n style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></= p></div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-fami= ly:"Courier New";color:#002060'>There are fundamentally two signaling optio= ns for such T.38 configurations:</span><span style=3D'font-size:10.0pt;font= -family:"Courier New"'><o:p></o:p></span></p></div><ol start=3D1 type=3Da><= li class=3DMsoNormal style=3D'color:#002060;mso-margin-top-alt:auto;mso-mar= gin-bottom-alt:auto;mso-list:l2 level1 lfo5'><b><span style=3D'font-size:10= .0pt;font-family:"Courier New"'>SDP-based</span></b><span style=3D'font-siz= e:10.0pt;font-family:"Courier New"'>: using <b>T.38 Annex D</b> defined SDP= elements embedded in H.248 descriptors<o:p></o:p></span></li><li class=3DM= soNormal style=3D'color:#002060;mso-margin-top-alt:auto;mso-margin-bottom-a= lt:auto;mso-list:l2 level1 lfo5'><b><span style=3D'font-size:10.0pt;font-fa= mily:"Courier New"'>Property-based</span></b><span style=3D'font-size:10.0p= t;font-family:"Courier New"'>: using <b>H.248.2, IP Fax package</b> defined= properties, such as specified by clauses 10.1.3 to 10.1.7<o:p></o:p></span= ></li></ol><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-f= amily:"Calibri","sans-serif";color:#002060'> </span><span style=3D'fon= t-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div><div><= p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courier Ne= w";color:#002060'>Both H.248 signalling options are basically equivalent, -= independent of SDP- or Property-based signaling elements. The signaling el= ements relate to the T.38 endpoint, but NOT to any remote G3FE.</span><span= style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p= ></div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-famil= y:"Courier New";color:#002060'>[Note: the H.248 IP fax package version 1 (f= rom 2005/2007) does not yet contain the latest T.38V4 (2010) parameter. But= this aspect is irrelevant in this discussion due to the proposal in 3GPP f= or the SDP-based method.]</span><span style=3D'font-size:10.0pt;font-family= :"Courier New"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span= style=3D'font-size:10.0pt;font-family:"Calibri","sans-serif";color:#002060= '> </span><span style=3D'font-size:10.0pt;font-family:"Courier New"'><= o:p></o:p></span></p></div><div><p class=3DMsoNormal><span style=3D'font-si= ze:10.0pt;font-family:"Courier New";color:#002060'>Thus,</span><span style= =3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div= ><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Cou= rier New";color:#002060'>all “T.38 SDP attributes” (in C3-12132= 7) are related to gateway capabilities (such as supported T.38 configuratio= ns by an IM-MGW implementation) (NOTE: attached is T.38 Table B.1 for H.323= gateways, which again underlines the relation to gateway capabilities).</s= pan><span style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p><= /span></p></div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;f= ont-family:"Courier New";color:#002060'>The MGC / MGCF may be either</span>= <span style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></spa= n></p></div><ol start=3D1 type=3Da><li class=3DMsoNormal style=3D'color:#00= 2060;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 = lfo8'><span style=3D'font-size:10.0pt;font-family:"Courier New"'>aware of t= he supported T.38 configuration(s) by his associated MGs or<o:p></o:p></spa= n></li><li class=3DMsoNormal style=3D'color:#002060;mso-margin-top-alt:auto= ;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo8'><span style=3D'font-si= ze:10.0pt;font-family:"Courier New"'>unaware.<o:p></o:p></span></li></ol><d= iv><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courie= r New";color:#002060'>Awareness may be achieved via auditing or configurati= on management.</span><span style=3D'font-size:10.0pt;font-family:"Courier N= ew"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span style=3D'f= ont-size:10.0pt;font-family:"Courier New";color:#002060'>Unawareness is bas= ically possible, but may lead to inefficient or even ineffective H.248 scen= arios for T.38.</span><span style=3D'font-size:10.0pt;font-family:"Courier = New"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span style=3D'= font-size:10.0pt;font-family:"Courier New";color:#002060'>Dependent on the = amount of “supported T.38 configuration(s)” knowledge at MGC le= vel would be the content of the SIP-level SDP O/A procedures.</span><span s= tyle=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p><= /div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:= "Calibri","sans-serif";color:#002060'> </span><span style=3D'font-size= :10.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div><div><p clas= s=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courier New";col= or:#002060'>Conclusions for <b>C3-121327</b> (<a href=3D"http://www.3gpp.or= g/ftp/tsg_ct/WG3_interworking_ex-CN3/TSGC3_70_Chicago/Docs/C3-121327.zip">h= ttp://www.3gpp.org/ftp/tsg_ct/WG3_interworking_ex-CN3/TSGC3_70_Chicago/Docs= /C3-121327.zip</a>):</span><span style=3D'font-size:10.0pt;font-family:"Cou= rier New"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span styl= e=3D'font-size:10.0pt;font-family:"Courier New";color:#002060'>NOTEs 1 and = 2 in Table X.3.1 are incorrect in my opinion.</span><span style=3D'font-siz= e:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div><div><p cla= ss=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courier New";co= lor:#002060'>The <b>text</b> related to “remote CS FAX equipment̶= 1; (term should be anyway replaced by term G3FE) should be just <b>deleted<= /b>. And there would be correspondent changes at other tables.</span><span = style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p>= </div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-family= :"Calibri","sans-serif";color:#002060'> </span><span style=3D'font-siz= e:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p></div><div><p cla= ss=3DMsoNormal><span style=3D'font-size:10.0pt;font-family:"Courier New";co= lor:#002060'>-Albrecht</span><span style=3D'font-size:10.0pt;font-family:"C= ourier New"'><o:p></o:p></span></p></div><div><p class=3DMsoNormal><span st= yle=3D'font-size:10.0pt;font-family:"Calibri","sans-serif";color:#002060'>&= nbsp;</span><span style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p= ></o:p></span></p></div><div><p class=3DMsoNormal><span style=3D'font-size:= 10.0pt;font-family:"Calibri","sans-serif";color:#C00000'> </span><span= style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p= ></div><div><p class=3DMsoNormal><span style=3D'font-size:10.0pt;font-famil= y:"Courier New"'><o:p> </o:p></span></p></div><div><p class=3DMsoNorma= l><span style=3D'font-size:10.0pt;font-family:"Calibri","sans-serif"'> = ;</span><span style=3D'font-size:10.0pt;font-family:"Courier New"'><o:p></o= :p></span></p></div></div></body></html>= --_000_5F7BCCF5541B7444830A2288ABBEBC96218B57EDCDFRMRSSXCHMBSD_-- --===============3520707778224723348== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Megaco mailing list [email protected] https://www.ietf.org/mailman/listinfo/megaco --===============3520707778224723348==--