January 2005 - sg16-avd - lists.packetizer.com

Contributions to the Melbourne meeting
by OKUBO Sakae 30 Jan '05

30 Jan '05

Dear WP2/16 experts, This is to remind you of the following dates: /// Registration of the document: by 23:59 UTC, 18 February 2005 /// /// Distribution of the document: by 23:59 UTC, 21 February 2005 /// The current list of registered documents can be found at the following place: http://ftp3.itu.int/av-arch/avc-site/2005-2008/0502_Mel/0502_Mel.html http://ftp3.itu.int/av-arch/avc-site/2005-2008/0502_Mel/0502_Mel.xls So far AVD-2588 through AVD-2631 have been registered. You can … [View More]

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RE: Proposal to support AMR codec in H.245 using RFC3267
by Venkata Nanduri 27 Jan '05

27 Jan '05

Hi, Thanks for the information. please see in line.... At 09:32 AM 1/27/2005 +0200, ari.lakaniemi(a)nokia.com wrote: >hello, > >Although the background of the issues I mentioned about the "mode-set" and >"mode-change-period" parameters is the limitations of the GSM signaling, >this is not explicitly mentioned in RFC 3267. This will be at least >somewhat clarified in the updated version. However, the point I was trying >to make is that a user that is not a gateway to … [View More]GSM system should be >discouraged to set up a session with limitations in mode changes to avoid >interoperability problems. Maybe this could somehow addressed in your draft? <vnanduri> I think it will be good if the limitations about GSM signaling are mentioned in your updated draft rather than the proposal that I will be submitting which is based on RFC 3267 so that readers of RFC 3267 get that info from your updated draft. Any idea on when this latest draft mentioned below will replace RFC3267? Do you think the proposal to H.245 should be based on this latest draft now? Venkata >The problem about the "mode-change-period"'s actual meaning (i.e. is it a >sender capability or a receiver limitation) was identified only after the >RFC 3267 was published in this is not mentioned in the spec. > >We have tried to clarify these issues in the new draft revision of the >update to RFC 3267 publishded on Jan. 26 (see >http://www.ietf.org/internet-drafts/draft-ietf-avt-rtp-amr-bis-01.txt) >Note that there are major changes only in section 8, see especially a new >parameter "mode-change-capability" and slightly changed definitions for >parameters "mode-change-period" and "mode-change-neighbor". > >br, >Ari > >-----Original Message----- >From: ext Venkata Nanduri [mailto:vnanduri@cisco.com] >Sent: 27 January, 2005 08:13 >To: Lakaniemi Ari (Nokia-NRC/Helsinki) >Cc: roni.even(a)polycom.co.il; itu-sg16(a)external.cisco.com; Hagqvist Jari >(Nokia-NRC/Tampere); vdukki(a)cisco.com >Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > > >Hi, > >Please see on line.... > >At 09:58 AM 1/26/2005 +0200, ari.lakaniemi(a)nokia.com wrote: > >hello Venkata, > >Thanks for the explanations. It seems that I was not reading thoroughly >enough since I missed the CRC and robust-sorting features incorporated >into the octetAlign parameter. > >Some furhter comments below. > >modeSet: >OK, I can see the reasoning behind the modeSet definition as it is written >in your draft. However, since absence of modeSet would mean a session >without any allowed modes, wouldn't it make sense to make this parameter >mandatory? > ><vnanduri> This parameter can be made mandatory. > > >(Note also that in RFC 3267 the parameter mode-set is introduced only to >enable connections (through a gateway) to GSM networks, which can only >support mode-sets of up to 4 AMR modes. I think in 'normal' VoIP usage the >full set of AMR modes should be supported.) > > ><vnanduri> I think RFC3267 does not mention about the restrictions >mentioned above. If so, can you please point me to the section? > > > > >modeChangePeriod: >This is also something that is defined in RFC 3267 only for interopreation >with GSM (where the signaling is limited in such a way that mode changes >are restricted to happen in 2-frame intervals). Thus, I think other values >than (1 or) 2 are not meaningful in practice. I do not know if this >document would be a right place to include an informational note about this... > >There is actually an identified problem regarding this in RFC 3267: does >the parameter mode-change-period indicate sender's capability to send >(also) using mode-change-period=2 (since the AMR _codec_ does not have >such limitation) or receiver's capability to _only_ receive using >mode-change-period=2? We are currently preapring an update for RFC 3267 >(which will be eventually published with different RFC number) to clarify >this (among some other things). > > ><vnanduri> I think RFC3267 does not mention about the restrictions >mentioned above. If so, can you please point me to the section? > >On Internet I could find ietf-avt-rtp-amr-bis-00.txt. But, that may not be >the latest. >Can you please send me the latest draft that is in progress(updated rfc3267)? > >Thanks >Venkata > > > > > >br, >Ari > > > -----Original Message----- > > From: ext Venkata Nanduri [mailto:vnanduri@cisco.com] > > Sent: 26 January, 2005 00:16 > > To: Lakaniemi Ari (Nokia-NRC/Helsinki) > > Cc: roni.even(a)polycom.co.il; itu-sg16(a)external.cisco.com; > > Hagqvist Jari > > (Nokia-NRC/Tampere) > > Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > > Importance: High > > > > > > Hi, > > > > Please see in line..... > > > > Look for vnanduri > > > > At 03:47 PM 1/25/2005 +0200, ari.lakaniemi(a)nokia.com wrote: > > >hello Venkata, > > > > > >Thanks for preparing the document. > > > > > >I have more or less the same comment as Roni Even already made: > > >There seems to be no parameters for controlling the "crc" and > > >"robust-sorting" options available in RFC 3267. Are these > > options somehow > > >problematic in the scope of H.245? > > > > > > <vnanduri> > > > > In-order to apply CRC, interleaving and robust-sorting , > > frame format shall > > be octet aligned. > > Since there is a dependency among different parameters, octetAlign > > parameter is defined in > > H245 which also handles CRC and robust-sorting. May be I need > > to rename > > this octetAlign > > parameter to something that is meaningful for octetAlign, CRC and > > robust-sorting (Any suggestions??) > > The presence of octetAlign parameter itself indicates octet > > aligned frame > > format. > > > > The octetAlign parameter is defined as booleanArray to take > > care of CRC and > > robust-sorting > > values. Bit 0 is used for CRC and Bit 1 for robust-sorting. > > > > But, interleaving can also be only applied if the frame format is > > octet-aligned and the value for > > interleaving is number of frame blocks which cannot be > > defined as part of > > booleanArray. So, a > > new parameter is defined. Interleaving parameter shall be absent if > > octetAlign parameter is absent. > > > > The main intention of consolidating the parameters is to > > minimize the bits > > that will be transmitted > > across the wire... > > > > > > >Another question is about the definition of the capability > > parameter modeSet. > > >Currently the draft specifies that > > > > > > "... If present, specifies the subset of modes available > > for current > > > session. If absent, no modes are supported." > > > > > >However, in RFC 3267 the definition of the corresponding > > MIME parameter says > > > "... If not present, all codec modes are allowed for the session." > > > > > >Maybe it would be clearer to use the same interpretation as > > in RFC 3267 in > > >case the paramter modeSet is not present? > > > > > > <vnanduri> > > > > For some of the parameters defined in RFC3267, similar parameters are > > defined with a different interpretation in H.245 > > to take care of conference scenarios. > > > > Please look below for details about why they are defined > > differently in H.245: > > > > > > 1) octet-align(SDP) -------->octetAlign--booleanArray (also > > accommodates > > crc and robust-sorting)(H.245) > > > > described above > > > > 2) mode-set(SDP) ---------->modeSet and modeSetExtended. > > modeSetExtended is > > used only AMR-WB(H245) > > > > modeSet is defined as booleanArray which can accommodate only > > 8 boolean > > values. Since AMR-NB has only > > 8 bit rates, modeSet parameter will be sufficient for AMR-NB. > > How ever, > > since AMR-WB has 9 modes, first > > 8 modes will be accommodated in modeSet parameter and 9th > > mode will be > > accommodated in > > modeSetExtended parameter. > > > > Suppose an MC that is not aware of AMR codec capability, gets this > > capability from three endpoints A, B and C > > and wants to create a common capability description. Suppose > > A sends no > > modeSet, B sends a modeSet with > > 10000011 and C sends a modeSet with 10000001. Now, a common > > capability > > description should contain the > > modeSet as 10000001. But the MC has to ignore those > > parameters that are not > > supported by all endpoints. > > > > So the MC will send out a cap description without a modeSet, > > which will > > imply support for all modes, which is not > > the expected behavior. So, absence of this parameter is > > defined as lack of > > support of any modes. > > > > The same comment applies for modeSetExtended - the absence of > > the parameter > > should indicate lack of support for > > the 9th mode, and this parameter should be present if the > > 9th mode is > > supported. > > > > 3) mode-change-period(SDP) ----->modeChangePeriod(H245). > > > > For modeChangePeriod, for example, if A sent a period of 5, B > > sent 3 and C > > did not > > send anything, the common cap description prepared by the MC > > will not contain a > > modeChangePeriod. So A, which could only change modes once in > > 5 frames will > > now receive audio that may changes mode at every frame which > > is not the > > expected > > behavior. Hence, this parameter is made mandatory and is > > defined as unsignedMax > > which indicates to MC that it has to select the largest value > > it receives > > from different > > end points. With this definition in H.245 Now, C has to > > send 0 as the value, > > and MC will select 5 which is the appropriate value. > > > > 4) mode-change-neighbor(SDP) -----> modeChangeAll(H245) > > > > For example, if A did not send, B sent with value 1, C sent > > value of 0, > > > > Again, an MC that does not include the value because one > > endpoint did not > > include. > > It will be creating a common capability description that indicates > > permission to > > switch to any mode(absence of param from A or a value 0 from > > C). Again > > this is not > > the expected behavior. > > > > So, this parameter is defined as 'ModeChangeAll'. The > > presence of this > > parameter > > means 'change from any to any mode is permitted'. Then if a > > combining MC > > creates > > a cap description that does not have ModeChangeAll (because > > one endpoint > > did not send it), > > it will be correctly forcing all endpoints to the common > > subset which is > > change to neighboring > > modes only is permitted'. > > > > > > 5) maxptime(SDP) ----------> alAduFrames(H.245) > > 6) ptime(DSP)-------> alAduFrames(H245) > > > > numFrames parameter will correspond to the value for maxptime > > when used in > > TCS messages and will correspond to value for ptime when used > > in OLC and MR > > messages. > > > > 7) crc(SDP) -----------> octetAlign(H.245) > > > > described above > > > > 8) robust-sorting(SDP) ------> octetAlign(H.245) > > > > described above > > > > 9) interleaving(SDP) -----> interleaving(H.245) > > > > described above > > > > 10) channels(SDP) -----> numChannels(H245) > > > > Same as SDP > > > > Please let me know if you have any other questions... > > > > Thanks > > Venkata > > > > > > >BR, > > >Ari Lakaniemi > > >Nokia Research Center > > > > > > > -----Original Message----- > > > > From: ext Even, Roni [mailto:roni.even@polycom.co.il] > > > > Sent: 25 January, 2005 10:10 > > > > To: Venkata Nanduri; itu-sg16(a)external.cisco.com; Lakaniemi Ari > > > > (Nokia-NRC/Helsinki) > > > > Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > > > > > > > > > > > > Hi, > > > > I just scanned through the draft. I noticed that there is no full > > > > mapping of the SDP parameters from RFC3267 to generic > > parameters. Is > > > > there a reason for the difference. > > > > I think that there should be some text that will explain the > > > > relationship to H.245 annex I. > > > > Roni Even > > > > > > > > -----Original Message----- > > > > From: Venkata Nanduri [mailto:vnanduri@cisco.com] > > > > Sent: Tuesday, January 25, 2005 12:33 AM > > > > To: itu-sg16(a)external.cisco.com; ari.lakaniemi(a)NOKIA.COM > > > > Cc: vnanduri(a)cisco.com > > > > Subject: Proposal to support AMR codec in H.245 using RFC3267 > > > > > > > > Dear SG16 experts, > > > > > > > > I would like the attached proposal to be submitted to > > next meeting of > > > > SG16 > > > > group to be held at > > > > Melbourne in February last week, 2005. > > > > > > > > Before I submit the proposal formally, I would like to > > get some early > > > > feedback on the proposal > > > > from experts in the group. > > > > > > > > Can you please review the document and let me know your comments? > > > > > > > > Thanks > > > > Venkata > > > > > > [View Less]

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RE: Proposal to support AMR codec in H.245 using RFC3267
by Venkata Nanduri 27 Jan '05

27 Jan '05

Hi, Please see on line.... At 09:58 AM 1/26/2005 +0200, ari.lakaniemi(a)nokia.com wrote: hello Venkata, Thanks for the explanations. It seems that I was not reading thoroughly enough since I missed the CRC and robust-sorting features incorporated into the octetAlign parameter. Some furhter comments below. modeSet: OK, I can see the reasoning behind the modeSet definition as it is written in your draft. However, since absence of modeSet would mean a session without any allowed modes, … [View More]wouldn't it make sense to make this parameter mandatory? <vnanduri> This parameter can be made mandatory. (Note also that in RFC 3267 the parameter mode-set is introduced only to enable connections (through a gateway) to GSM networks, which can only support mode-sets of up to 4 AMR modes. I think in 'normal' VoIP usage the full set of AMR modes should be supported.) <vnanduri> I think RFC3267 does not mention about the restrictions mentioned above. If so, can you please point me to the section? modeChangePeriod: This is also something that is defined in RFC 3267 only for interopreation with GSM (where the signaling is limited in such a way that mode changes are restricted to happen in 2-frame intervals). Thus, I think other values than (1 or) 2 are not meaningful in practice. I do not know if this document would be a right place to include an informational note about this... There is actually an identified problem regarding this in RFC 3267: does the parameter mode-change-period indicate sender's capability to send (also) using mode-change-period=2 (since the AMR _codec_ does not have such limitation) or receiver's capability to _only_ receive using mode-change-period=2? We are currently preapring an update for RFC 3267 (which will be eventually published with different RFC number) to clarify this (among some other things). <vnanduri> I think RFC3267 does not mention about the restrictions mentioned above. If so, can you please point me to the section? On Internet I could find ietf-avt-rtp-amr-bis-00.txt. But, that may not be the latest. Can you please send me the latest draft that is in progress(updated rfc3267)? Thanks Venkata br, Ari > -----Original Message----- > From: ext Venkata Nanduri [mailto:vnanduri@cisco.com] > Sent: 26 January, 2005 00:16 > To: Lakaniemi Ari (Nokia-NRC/Helsinki) > Cc: roni.even(a)polycom.co.il; itu-sg16(a)external.cisco.com; > Hagqvist Jari > (Nokia-NRC/Tampere) > Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > Importance: High > > > Hi, > > Please see in line..... > > Look for vnanduri > > At 03:47 PM 1/25/2005 +0200, ari.lakaniemi(a)nokia.com wrote: > >hello Venkata, > > > >Thanks for preparing the document. > > > >I have more or less the same comment as Roni Even already made: > >There seems to be no parameters for controlling the "crc" and > >"robust-sorting" options available in RFC 3267. Are these > options somehow > >problematic in the scope of H.245? > > > <vnanduri> > > In-order to apply CRC, interleaving and robust-sorting , > frame format shall > be octet aligned. > Since there is a dependency among different parameters, octetAlign > parameter is defined in > H245 which also handles CRC and robust-sorting. May be I need > to rename > this octetAlign > parameter to something that is meaningful for octetAlign, CRC and > robust-sorting (Any suggestions??) > The presence of octetAlign parameter itself indicates octet > aligned frame > format. > > The octetAlign parameter is defined as booleanArray to take > care of CRC and > robust-sorting > values. Bit 0 is used for CRC and Bit 1 for robust-sorting. > > But, interleaving can also be only applied if the frame format is > octet-aligned and the value for > interleaving is number of frame blocks which cannot be > defined as part of > booleanArray. So, a > new parameter is defined. Interleaving parameter shall be absent if > octetAlign parameter is absent. > > The main intention of consolidating the parameters is to > minimize the bits > that will be transmitted > across the wire... > > > >Another question is about the definition of the capability > parameter modeSet. > >Currently the draft specifies that > > > > "... If present, specifies the subset of modes available > for current > > session. If absent, no modes are supported." > > > >However, in RFC 3267 the definition of the corresponding > MIME parameter says > > "... If not present, all codec modes are allowed for the session." > > > >Maybe it would be clearer to use the same interpretation as > in RFC 3267 in > >case the paramter modeSet is not present? > > > <vnanduri> > > For some of the parameters defined in RFC3267, similar parameters are > defined with a different interpretation in H.245 > to take care of conference scenarios. > > Please look below for details about why they are defined > differently in H.245: > > > 1) octet-align(SDP) -------->octetAlign--booleanArray (also > accommodates > crc and robust-sorting)(H.245) > > described above > > 2) mode-set(SDP) ---------->modeSet and modeSetExtended. > modeSetExtended is > used only AMR-WB(H245) > > modeSet is defined as booleanArray which can accommodate only > 8 boolean > values. Since AMR-NB has only > 8 bit rates, modeSet parameter will be sufficient for AMR-NB. > How ever, > since AMR-WB has 9 modes, first > 8 modes will be accommodated in modeSet parameter and 9th > mode will be > accommodated in > modeSetExtended parameter. > > Suppose an MC that is not aware of AMR codec capability, gets this > capability from three endpoints A, B and C > and wants to create a common capability description. Suppose > A sends no > modeSet, B sends a modeSet with > 10000011 and C sends a modeSet with 10000001. Now, a common > capability > description should contain the > modeSet as 10000001. But the MC has to ignore those > parameters that are not > supported by all endpoints. > > So the MC will send out a cap description without a modeSet, > which will > imply support for all modes, which is not > the expected behavior. So, absence of this parameter is > defined as lack of > support of any modes. > > The same comment applies for modeSetExtended - the absence of > the parameter > should indicate lack of support for > the 9th mode, and this parameter should be present if the > 9th mode is > supported. > > 3) mode-change-period(SDP) ----->modeChangePeriod(H245). > > For modeChangePeriod, for example, if A sent a period of 5, B > sent 3 and C > did not > send anything, the common cap description prepared by the MC > will not contain a > modeChangePeriod. So A, which could only change modes once in > 5 frames will > now receive audio that may changes mode at every frame which > is not the > expected > behavior. Hence, this parameter is made mandatory and is > defined as unsignedMax > which indicates to MC that it has to select the largest value > it receives > from different > end points. With this definition in H.245 Now, C has to > send 0 as the value, > and MC will select 5 which is the appropriate value. > > 4) mode-change-neighbor(SDP) -----> modeChangeAll(H245) > > For example, if A did not send, B sent with value 1, C sent > value of 0, > > Again, an MC that does not include the value because one > endpoint did not > include. > It will be creating a common capability description that indicates > permission to > switch to any mode(absence of param from A or a value 0 from > C). Again > this is not > the expected behavior. > > So, this parameter is defined as 'ModeChangeAll'. The > presence of this > parameter > means 'change from any to any mode is permitted'. Then if a > combining MC > creates > a cap description that does not have ModeChangeAll (because > one endpoint > did not send it), > it will be correctly forcing all endpoints to the common > subset which is > change to neighboring > modes only is permitted'. > > > 5) maxptime(SDP) ----------> alAduFrames(H.245) > 6) ptime(DSP)-------> alAduFrames(H245) > > numFrames parameter will correspond to the value for maxptime > when used in > TCS messages and will correspond to value for ptime when used > in OLC and MR > messages. > > 7) crc(SDP) -----------> octetAlign(H.245) > > described above > > 8) robust-sorting(SDP) ------> octetAlign(H.245) > > described above > > 9) interleaving(SDP) -----> interleaving(H.245) > > described above > > 10) channels(SDP) -----> numChannels(H245) > > Same as SDP > > Please let me know if you have any other questions... > > Thanks > Venkata > > > >BR, > >Ari Lakaniemi > >Nokia Research Center > > > > > -----Original Message----- > > > From: ext Even, Roni [mailto:roni.even@polycom.co.il] > > > Sent: 25 January, 2005 10:10 > > > To: Venkata Nanduri; itu-sg16(a)external.cisco.com; Lakaniemi Ari > > > (Nokia-NRC/Helsinki) > > > Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > > > > > > > > > Hi, > > > I just scanned through the draft. I noticed that there is no full > > > mapping of the SDP parameters from RFC3267 to generic > parameters. Is > > > there a reason for the difference. > > > I think that there should be some text that will explain the > > > relationship to H.245 annex I. > > > Roni Even > > > > > > -----Original Message----- > > > From: Venkata Nanduri [mailto:vnanduri@cisco.com] > > > Sent: Tuesday, January 25, 2005 12:33 AM > > > To: itu-sg16(a)external.cisco.com; ari.lakaniemi(a)NOKIA.COM > > > Cc: vnanduri(a)cisco.com > > > Subject: Proposal to support AMR codec in H.245 using RFC3267 > > > > > > Dear SG16 experts, > > > > > > I would like the attached proposal to be submitted to > next meeting of > > > SG16 > > > group to be held at > > > Melbourne in February last week, 2005. > > > > > > Before I submit the proposal formally, I would like to > get some early > > > feedback on the proposal > > > from experts in the group. > > > > > > Can you please review the document and let me know your comments? > > > > > > Thanks > > > Venkata > > > > [View Less]

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RE: Proposal to support AMR codec in H.245 using RFC3267
by simao.campos＠ITU.INT 26 Jan '05

26 Jan '05

All, I think that it would be too confusing to have two annexes dealing with the same coding. I suggest that Annex I be revised, even if it means a total rewriting of it. Just consider whether the previous definitions should be maintained as a matter of backward compatibility with existing systems. Best regards, Simao > -----Original Message----- > From: Venkata Nanduri [mailto:vnanduri@cisco.com] > Sent: 26 January 2005 03:04 > To: Dave Lindbergh > Cc: itu-sg16(a)… [View More]

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Re: Proposal to support AMR codec in H.245 using RFC3267
by Venkata Nanduri 25 Jan '05

25 Jan '05

Hi, I think existing Annex - I in H.245 is written much before RFC3267 is written and hence it out of sync in content. The RTP format mentioned in Annex - I is different from what is mentioned in RFC3267. Even if we want to incorporate this material in existing Annex - I, it will be like replacing the entire Annex - I content with the new content.. Thanks Venkata At 07:50 PM 1/25/2005 -0500, Dave Lindbergh wrote: >Is there a reason why this needs to be a separate Annex to H.245? I'… [View More]

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Re: Proposal to support AMR codec in H.245 using RFC3267
by Dave Lindbergh 25 Jan '05

25 Jan '05

Is there a reason why this needs to be a separate Annex to H.245? I'd prefer to incorporate this material into an existing Annex, just to reduce the amount of clutter in H.245. --Dave At 05:32 PM 1/24/2005, Venkata Nanduri wrote: >Dear SG16 experts, > >I would like the attached proposal to be submitted to next meeting of SG16 >group to be held at >Melbourne in February last week, 2005. > >Before I submit the proposal formally, I would like to get some early >… [View More]

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RE: Proposal to support AMR codec in H.245 using RFC3267
by Venkata Nanduri 25 Jan '05

25 Jan '05

Hi, Please see in line..... Look for vnanduri At 03:47 PM 1/25/2005 +0200, ari.lakaniemi(a)nokia.com wrote: >hello Venkata, > >Thanks for preparing the document. > >I have more or less the same comment as Roni Even already made: >There seems to be no parameters for controlling the "crc" and >"robust-sorting" options available in RFC 3267. Are these options somehow >problematic in the scope of H.245? <vnanduri> In-order to apply CRC, interleaving and robust-… [View More]sorting , frame format shall be octet aligned. Since there is a dependency among different parameters, octetAlign parameter is defined in H245 which also handles CRC and robust-sorting. May be I need to rename this octetAlign parameter to something that is meaningful for octetAlign, CRC and robust-sorting (Any suggestions??) The presence of octetAlign parameter itself indicates octet aligned frame format. The octetAlign parameter is defined as booleanArray to take care of CRC and robust-sorting values. Bit 0 is used for CRC and Bit 1 for robust-sorting. But, interleaving can also be only applied if the frame format is octet-aligned and the value for interleaving is number of frame blocks which cannot be defined as part of booleanArray. So, a new parameter is defined. Interleaving parameter shall be absent if octetAlign parameter is absent. The main intention of consolidating the parameters is to minimize the bits that will be transmitted across the wire... >Another question is about the definition of the capability parameter modeSet. >Currently the draft specifies that > > "... If present, specifies the subset of modes available for current > session. If absent, no modes are supported." > >However, in RFC 3267 the definition of the corresponding MIME parameter says > "... If not present, all codec modes are allowed for the session." > >Maybe it would be clearer to use the same interpretation as in RFC 3267 in >case the paramter modeSet is not present? <vnanduri> For some of the parameters defined in RFC3267, similar parameters are defined with a different interpretation in H.245 to take care of conference scenarios. Please look below for details about why they are defined differently in H.245: 1) octet-align(SDP) -------->octetAlign--booleanArray (also accommodates crc and robust-sorting)(H.245) described above 2) mode-set(SDP) ---------->modeSet and modeSetExtended. modeSetExtended is used only AMR-WB(H245) modeSet is defined as booleanArray which can accommodate only 8 boolean values. Since AMR-NB has only 8 bit rates, modeSet parameter will be sufficient for AMR-NB. How ever, since AMR-WB has 9 modes, first 8 modes will be accommodated in modeSet parameter and 9th mode will be accommodated in modeSetExtended parameter. Suppose an MC that is not aware of AMR codec capability, gets this capability from three endpoints A, B and C and wants to create a common capability description. Suppose A sends no modeSet, B sends a modeSet with 10000011 and C sends a modeSet with 10000001. Now, a common capability description should contain the modeSet as 10000001. But the MC has to ignore those parameters that are not supported by all endpoints. So the MC will send out a cap description without a modeSet, which will imply support for all modes, which is not the expected behavior. So, absence of this parameter is defined as lack of support of any modes. The same comment applies for modeSetExtended - the absence of the parameter should indicate lack of support for the 9th mode, and this parameter should be present if the 9th mode is supported. 3) mode-change-period(SDP) ----->modeChangePeriod(H245). For modeChangePeriod, for example, if A sent a period of 5, B sent 3 and C did not send anything, the common cap description prepared by the MC will not contain a modeChangePeriod. So A, which could only change modes once in 5 frames will now receive audio that may changes mode at every frame which is not the expected behavior. Hence, this parameter is made mandatory and is defined as unsignedMax which indicates to MC that it has to select the largest value it receives from different end points. With this definition in H.245 Now, C has to send 0 as the value, and MC will select 5 which is the appropriate value. 4) mode-change-neighbor(SDP) -----> modeChangeAll(H245) For example, if A did not send, B sent with value 1, C sent value of 0, Again, an MC that does not include the value because one endpoint did not include. It will be creating a common capability description that indicates permission to switch to any mode(absence of param from A or a value 0 from C). Again this is not the expected behavior. So, this parameter is defined as 'ModeChangeAll'. The presence of this parameter means 'change from any to any mode is permitted'. Then if a combining MC creates a cap description that does not have ModeChangeAll (because one endpoint did not send it), it will be correctly forcing all endpoints to the common subset which is change to neighboring modes only is permitted'. 5) maxptime(SDP) ----------> alAduFrames(H.245) 6) ptime(DSP)-------> alAduFrames(H245) numFrames parameter will correspond to the value for maxptime when used in TCS messages and will correspond to value for ptime when used in OLC and MR messages. 7) crc(SDP) -----------> octetAlign(H.245) described above 8) robust-sorting(SDP) ------> octetAlign(H.245) described above 9) interleaving(SDP) -----> interleaving(H.245) described above 10) channels(SDP) -----> numChannels(H245) Same as SDP Please let me know if you have any other questions... Thanks Venkata >BR, >Ari Lakaniemi >Nokia Research Center > > > -----Original Message----- > > From: ext Even, Roni [mailto:roni.even@polycom.co.il] > > Sent: 25 January, 2005 10:10 > > To: Venkata Nanduri; itu-sg16(a)external.cisco.com; Lakaniemi Ari > > (Nokia-NRC/Helsinki) > > Subject: RE: Proposal to support AMR codec in H.245 using RFC3267 > > > > > > Hi, > > I just scanned through the draft. I noticed that there is no full > > mapping of the SDP parameters from RFC3267 to generic parameters. Is > > there a reason for the difference. > > I think that there should be some text that will explain the > > relationship to H.245 annex I. > > Roni Even > > > > -----Original Message----- > > From: Venkata Nanduri [mailto:vnanduri@cisco.com] > > Sent: Tuesday, January 25, 2005 12:33 AM > > To: itu-sg16(a)external.cisco.com; ari.lakaniemi(a)NOKIA.COM > > Cc: vnanduri(a)cisco.com > > Subject: Proposal to support AMR codec in H.245 using RFC3267 > > > > Dear SG16 experts, > > > > I would like the attached proposal to be submitted to next meeting of > > SG16 > > group to be held at > > Melbourne in February last week, 2005. > > > > Before I submit the proposal formally, I would like to get some early > > feedback on the proposal > > from experts in the group. > > > > Can you please review the document and let me know your comments? > > > > Thanks > > Venkata > > [View Less]

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RE: Proposal to support AMR codec in H.245 using RFC3267
by Even, Roni 25 Jan '05

25 Jan '05

Hi, I just scanned through the draft. I noticed that there is no full mapping of the SDP parameters from RFC3267 to generic parameters. Is there a reason for the difference. I think that there should be some text that will explain the relationship to H.245 annex I. Roni Even -----Original Message----- From: Venkata Nanduri [mailto:vnanduri@cisco.com] Sent: Tuesday, January 25, 2005 12:33 AM To: itu-sg16(a)external.cisco.com; ari.lakaniemi(a)NOKIA.COM Cc: vnanduri(a)cisco.com Subject: … [View More]

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Proposal to support AMR codec in H.245 using RFC3267
by Venkata Nanduri 24 Jan '05

24 Jan '05

Dear SG16 experts, I would like the attached proposal to be submitted to next meeting of SG16 group to be held at Melbourne in February last week, 2005. Before I submit the proposal formally, I would like to get some early feedback on the proposal from experts in the group. Can you please review the document and let me know your comments? Thanks Venkata

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Meeting Announcement Joined session Q.29/16 with SG19 in Melbour
by Leo.Lehmann＠bakom.admin.ch 24 Jan '05

24 Jan '05

Dear experts and colleagues, I have the pleasure to announce a joined session of Q.29/16 together with SG19 during our WP2 Rapporteuer Meeting in Melbourne. SG19 will held an Rapporteuer meeting from March 1st until March 3rd 2005 also in Melbourne. This givese a good opportunity for the exchange and handling of questions on mobility of SG16 and SG19. Unfortunally SG16/WP2 and SG19 uses different meeting locations in Melbourne, which are about 2 hours driving time away from each other. So far … [View More]one joined session is planned on morning March 1st at SG19 meeting place with WP2 participants , the other on March 2nd at WP2/16 meeting place with SG16 participants. Topics for this joined meeting will be so far - Consolidation of Mobility definitions - new Revision of Technical report on combined mobility betewwen H.323 systems and GPRS/UMTS networks - Further issues Regarding the first both items I am expecting two contributions until beginning of February. If you would like to send further contributions for this Session, please do not hesitate to bring them up until February 12th 2005. If you are interested to participate in the session at the SG19 meeting place, please send the attached registration to 'Leslie.Graf(a)ericsson.com'and please let me also know for information. Best regards Leo Leo Lehmann Rapporteur Q.29/16 Federal Office of Communication (OFCOM) Biel-Bienne Switzerland Tel: +41 32 327 5752 __________________________________________________________________________ __ ___________________________________________________ Dear Mr. Lehmann, At 11:45 +0100 05/01/24, Leo.Lehmann(a)bakom.admin.ch wrote: >I had a telefon conversation with Mr Probst. As this is a good >opportunity for Questions on mobility of SG16 and >SG19 to meet, Mr Probst fully support an additional setting of a >Q.29/16 meeting in Melbourne to enable a joined session with SG19 >qusetions. Thank you very much. Please publicize the Melbourne sessions on mobility through the mailing list. -- Best regards, OKUBO Sakae e-mail: sokubo(a)waseda.jp Visiting Professor Graduate School of Science and Engineering Waseda University ****************************************************************** Waseda University, YRP Ichibankan 312 Tel: +81 46 847 5406 3-4 Hikarinooka, Yokosuka-shi, Kanagawa-ken Fax: +81 46 847 5413 239-0847 Japan H.323 videoconferencing: arranged by advice ****************************************************************** Dear Mr Okubo, I had a telefon conversation with Mr Probst. As this is a good opportunity for Questions on mobility of SG16 and SG19 to meet, Mr Probst fully support an additional setting of a Q.29/16 meeting in Melbourne to enable a joined session with SG19 qusetions. Best regards Leo -----Ursprüngliche Nachricht----- Von: OKUBO Sakae [mailto:okubo@mxz.mesh.ne.jp] Gesendet: Sonntag, 23. Januar 2005 17:57 An: Lehmann Leo Cc: Simao Campos-Neto Betreff: Fwd:Re: Fwd:Q.29 interim meeting/joint meeting with SG19 Dear Mr. Lehmann, I have received the following auto-reply to my message seeking his agreement. Could you please kindly get in touch with him via the advised mobile phone and convey our request? It would be too late if we start after 30 March. >From: probst-pa(a)bluewin.ch >Subject: Re: Fwd:Q.29 interim meeting/joint meeting with SG19 >To: okubo(a)mxz.mesh.ne.jp >Date: Sun, 23 Jan 2005 16:43:56 +0000 >Delivered-To: probst-pa(a)bluewin.ch >X-Biglobe-VirusCheck: Mon, 24 Jan 2005 01:43:59 +0900 > >Thank you very much for your message. >I am away from my office for two weeks and will process your mail only >later (30.1.2005). For urgent issues, you have the possibility to reach >me on my mobile >phone: +41 79 229 96 56. > >Best regards, > >P.A.Probst -----Ursprüngliche Nachricht----- Von: OKUBO Sakae [mailto:okubo@mxz.mesh.ne.jp] Gesendet: Sonntag, 23. Januar 2005 17:44 An: Pierre-Andre PROBST Cc: Istvan Sebestyen; Simao Campos-Neto; Lehmann Leo; Christian Groves Betreff: Fwd:Q.29 interim meeting/joint meeting with SG19 Dear Mr. Probst, This is to seek your agreement on that Q.29 will meet in Melbourne early March as requested by Mr. Lehmann. Strictly speaking, the WP2/16 report of last SG16 meeting says that Q.29 will meet only in May and the current SG16 web page <http://www.itu.int/ITU-T/studygroups/com16/meetings.html> also indicates so. As this is a good opportunity for Questions on mobility of SG16 and SG19 to meet, I hope you could accept this additional setting. Best regards, OKUBO Sakae e-mail: sokubo(a)waseda.jp Visiting Professor Graduate School of Science and Engineering Waseda University ****************************************************************** Waseda University, YRP Ichibankan 312 Tel: +81 46 847 5406 3-4 Hikarinooka, Yokosuka-shi, Kanagawa-ken Fax: +81 46 847 5413 239-0847 Japan H.323 videoconferencing: arranged by advice ****************************************************************** -----Ursprüngliche Nachricht----- Von: John Visser [mailto:jvisser@nortelnetworks.com] Gesendet: Mittwoch, 19. Januar 2005 16:56 An: David.Mcfarlane(a)nokia.com; 'Farrokh Khatibi'; 'Felix,Zhang'; 'leo.lehmann(a)bakom.admin.ch' Cc: peter.m.adams(a)bt.com; Leslie Graf; tatiana.kurakova(a)itu.int Betreff: RE: documents for joint rapporteurs meeting Colleagues: I think everyone is aware of Q.29/16 "Mobility for Multimedia Systems and Services" http://www.itu.int/ITU-T/studygroups/com16/sg16-q29. Leo Lehman is the Rapporteur and he and I have had several discussions on how best to coordinate our mobility studies. Q.2 and 5/19 and Q.6/13 are meeting jointly in Melbourne 1-3 March. Q.29/16 is meeting in Marysville the week of 28 Feb. Marysville is about 2 hours drive outside Melbourne. In my discussions with Leo, we addressed how best to coordinate our work and we came up with the following proposal: Tuesday, 1 March, Leo (and possibly others) would come to Melbourne for the afternoon to take part in the Q.2 and 5/19 and Q.6/13 joint discussions. The objective would be to identify mobility-related definitions and terminology and work towards alignment so that these would be common across all mobility discussions. I anticipate that Leo would also be willing to provide an overview of the Work of Q.5/16 in the previous study period, and the current work anticipated in Q.29/16. Wednesday, 2 March, I (and possibly others) would go to Marysville to sit in on the Q.29/16 discussions. The objective would be to support alignment on mobility-related definitions and terminology from the previous day. I anticipate that I would also provide an overview of the work of Q.2 and 5/19 and Q.6/13. I would appreciate any comments and concerns from you prior to formalizing this further (though we don't want to get very formal at a rapporteurs' meeting.) Regards, John John Visser, P.Eng. Chairman, ITU-T SG 19 "Mobile Telecommunication Networks" http://www.itu.int/ITU-T/studygroups/com19 Phone: +1-613-763-7028 Fax: +1-613-763-2697 Mobile: +1-613-276-6096 Email: jvisser(a)nortel.com [View Less]

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