May 2001 - sg16-avd - lists.packetizer.com

Call for Participation: NOSSDAV 2001
by Henning Schulzrinne 07 May '01

07 May '01

CALL FOR PARTICIPATION The 11th International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV 2001) Sponsored by the Association for Computing Machinery In cooperation with USENIX, ACM SIGCOMM, ACM SIGMM, ACM SIGOPS Technically cosponsored by the IEEE Communications Society (pending) June 25-26, 2001 Danfords on the Sound, Port Jefferson, New York http://www.nossdav.org/2001 The 11th International Workshop on Network and Operating Systems Support for Digital Audio and Video (NOSSDAV 2001) will bring together participants from academia and industry to present and discuss new ideas and future directions in networking and operating system support for multimedia. Exponential improvements in networking bandwidth, cost, and ubiquity coupled with the growing availability and use of streaming media content pose new networking and operating system research opportunities and challenges at the global systems level. Papers on streaming media, quality of service, multicast, mobile multimedia, Internet telephony, and collaboration will be presented. Peter Danzig will deliver a keynote address on "Ideas for Next Generation Content Delivery". Important Dates: ================ Early registration deadline: May 19, 2001 Registration deadline: June 15, 2001 Workshop: June 25-27, 2001 NOSSDAV 2001 Organizing Committee: ================================= Chairs: Jason Nieh, Columbia University Henning Schulzrinne, Columbia University Kevin Almeroth, UCSB Peter Danzig, Akamai Christophe Diot, Sprint Advanced Technology Labs Wu-chi Feng, Ohio State University Anoop Gupta, Microsoft Research Chuck Kalmanek, AT&T Research Sneha Kasera, Lucent Technologies Duane Northcutt, Sun Microsystems Larry Peterson, Princeton University Dan Rubenstein, Columbia University Larry Rowe, University of California, Berkeley Brian Schmidt, Sun Microsystems Doug Shepherd, Lancaster University Chuck Yoo, Korea University Zhi-Li Zhang, University of Minnesota ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

H323 TOPICS
by Rogelio SIlva (CVS) 06 May '01

06 May '01

Could you please add my e-mail id to your mailing list on any H323 topics? Thanks, Rogelio Silva Director CVS Mexico Corporate Videoconferencing Services "Su oficina virtual en todo el mundo" www.cvs.com.mx Tel (525) 208-0690

1 0

DRQ and pre-granted ARQ
by Francois Audet 06 May '01

06 May '01

Guys, When pre-granted ARQ is used on a call (on either the originating or the terminating side), do we assume that DRQ is not required when clearing a call? Couldn't find it in H.323 or H.225.0. Thanks. ---- François AUDET, Nortel Networks mailto:audet@nortelnetworks.com <mailto:audet@nortelnetworks.com> , tel:+1 408 495 3756

2 1

Re: Emergency Services and Service classes
by Roy, Radhika R, ALCOO 03 May '01

03 May '01

Hi, Gary: OK, now I understand your proposal and appreciate it. Let me suggest how we can achieve the common goal: 1. Tom Taylor is analyzing the requirements of the emergency services. We will be able to take care of the "priority" levels that have been proposed by you. 2. Mike Buckley is working for QOS and we will be able to meet the requirements of "quality" levels proposed by you. However, the solutions of both depend on solving the bigger problems. That is, we have to create the overall framework especially for the QOS. Mike, myself, and other members of the SG16 are working for a long time on QOS and you are hereby requested to participate in those discussions. AT&T is also bringing contributions along the line for QOS and I have a proposal how we can meet your proposed requirements as well. Again, I appreciate your proposal because it helps to drive for finding a common solution. Best regards, Radhika -----Original Message----- From: Gary Thom [mailto:gthom@delta-info.com] Sent: Thursday, May 03, 2001 1:42 PM To: Roy, Radhika R; ITU-SG16(a)mailbag.cps.INTEL.COM Subject: RE: Emergency Services and Service classes Radhika, I agree, lets try to harmonize all the requirements for service class signalling. I would be happy to include other requirements, but I will need input from others. I tried to make this generic, and extensible. And not specific for emergency services. In particular, I have tried to abstract priority and quality (of media streams) from quality of service signalling. I understand that there is work being done on QOS signalling, and I am not trying to replace that, but maybe be one level above that. Gary -------------------------------------------- Name : Gary A. Thom Company: Delta Information Systems, Inc. Address: 300 Welsh Rd., Bldg 3 Horsham, PA 19044 USA Phone : +1-215-657-5270 x123 Fax : +1-215-657-5273 E-mail : gthom(a)delta-info.com Website: www.delta-info.com -------------------------------------------- -----Original Message----- From: Roy, Radhika R, ALCOO [mailto:rrroy@att.com] Sent: Thursday, May 03, 2001 11:58 AM To: gthom(a)delta-info.com; ITU-SG16(a)mailbag.cps.INTEL.COM Subject: RE: Emergency Services and Service classes Hi, Gary: I provided some comments before. So, the same comments remain true. The point is that we can accommodate the service class within the framework of other requirements along with the specific requirements that you have proposed. For example, priority can be: 1. MLLP, 2. Emergency Services (as proposed by you), and 3. Other standards/proposals. Similarly, quality proposed by you can also be accommodated: 1. IETF (guaranteed, controlled, best-effort), 2. TIPHON (Best, High, Medium, Best-Effort - as proposed by you), 3. Other ISTU-T SGs, and 3. Other standard bodies/forums. In addition, there are other things as well. For example, there is a relationship (or dependency) between the priority and QOS at the call level. RAS Messages only provide the pre-call level scenarios. This also needs to be translated into call level scenarios. So, the point that I like to point out is this: Let us address this from the general framework point of view so that all cases are satisfied including yours without "hard-wired" to any particular solution. AT&T is bringing contributions along this line for the QOS and others. Best regards, Radhika R. Roy -----Original Message----- From: Gary Thom [mailto:gthom@delta-info.com] Sent: Thursday, May 03, 2001 11:07 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Emergency Services and Service classes All, Attached is a preliimary copy of a contribution to the upcomming Brazil meeting. It still needs US approval. It defines service classes using the generic extensible framework, and should be more applicable than just emergency services. Extension markers were put in to allow addition of new priority and quality values. Let me know if you have any comments, suggestions, or questions. Thanks Gary -------------------------------------------- Name : Gary A. Thom Company: Delta Information Systems, Inc. Address: 300 Welsh Rd., Bldg 3 Horsham, PA 19044 USA Phone : +1-215-657-5270 x123 Fax : +1-215-657-5273 E-mail : gthom(a)delta-info.com Website: www.delta-info.com -------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

Re: Emergency Services and Service classes
by Roy, Radhika R, ALCOO 03 May '01

03 May '01

Hi, Gary: I provided some comments before. So, the same comments remain true. The point is that we can accommodate the service class within the framework of other requirements along with the specific requirements that you have proposed. For example, priority can be: 1. MLLP, 2. Emergency Services (as proposed by you), and 3. Other standards/proposals. Similarly, quality proposed by you can also be accommodated: 1. IETF (guaranteed, controlled, best-effort), 2. TIPHON (Best, High, Medium, Best-Effort - as proposed by you), 3. Other ISTU-T SGs, and 3. Other standard bodies/forums. In addition, there are other things as well. For example, there is a relationship (or dependency) between the priority and QOS at the call level. RAS Messages only provide the pre-call level scenarios. This also needs to be translated into call level scenarios. So, the point that I like to point out is this: Let us address this from the general framework point of view so that all cases are satisfied including yours without "hard-wired" to any particular solution. AT&T is bringing contributions along this line for the QOS and others. Best regards, Radhika R. Roy -----Original Message----- From: Gary Thom [mailto:gthom@delta-info.com] Sent: Thursday, May 03, 2001 11:07 AM To: ITU-SG16(a)MAILBAG.INTEL.COM Subject: Emergency Services and Service classes All, Attached is a preliimary copy of a contribution to the upcomming Brazil meeting. It still needs US approval. It defines service classes using the generic extensible framework, and should be more applicable than just emergency services. Extension markers were put in to allow addition of new priority and quality values. Let me know if you have any comments, suggestions, or questions. Thanks Gary -------------------------------------------- Name : Gary A. Thom Company: Delta Information Systems, Inc. Address: 300 Welsh Rd., Bldg 3 Horsham, PA 19044 USA Phone : +1-215-657-5270 x123 Fax : +1-215-657-5273 E-mail : gthom(a)delta-info.com Website: www.delta-info.com -------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

2 1

AW: Emergency Services and Service classes
by Horvath Ernst 03 May '01

03 May '01

Gary, after skimming over your contribution, two immediate comments: 1) QoS signalling within your serviceClass may overlap (or even conflict) with what will eventually appear in H.323 annex N. We should try to have QOS information in one place only. ServiceClass is one possible place, but then we should make sure that it covers also the requirements of annex N. 2) For the terminating side, the primary goal should be protection. In other words, the called party would be protected against calls below a certain class of service ("do not disturb unless it's urgent"), and existing calls would not be affected unless resources are needed for a call with higher priority. It may even be worthwhile to specify separate protection levels separate from priority levels. For example, the call intrusion supplementary service recently approved by SG16 (Rec. H.450.11) follows such a concept: the caller is only allowed to intrude on an established call if his capability level is higher than the combined protection levels of the called party and the remote party of the established call. Ernst Horvath Siemens AG > -----Ursprüngliche Nachricht----- > Von: Gary Thom [mailto:gthom@delta-info.com] > Gesendet am: Donnerstag, 03. Mai 2001 17:07 > An: ITU-SG16(a)mailbag.cps.INTEL.COM > Betreff: Emergency Services and Service classes > > All, > > Attached is a preliimary copy of a contribution to the > upcomming Brazil > meeting. It still needs US approval. > > It defines service classes using the generic extensible framework, and > should be more applicable than just emergency services. > Extension markers > were put in to allow addition of new priority and quality values. > > Let me know if you have any comments, suggestions, or questions. > > Thanks > Gary > > -------------------------------------------- > Name : Gary A. Thom > Company: Delta Information Systems, Inc. > Address: 300 Welsh Rd., Bldg 3 > Horsham, PA 19044 USA > Phone : +1-215-657-5270 x123 > Fax : +1-215-657-5273 > E-mail : gthom(a)delta-info.com > Website: www.delta-info.com > -------------------------------------------- >

1 0

Emergency Services and Service classes
by Gary Thom 03 May '01

03 May '01

I would like to re-open the discussion started at the Nov 2000 Geneva meeting and continued at the March 2001 Launceston meeting relating to Emergency Services. In order to support Emergency Services, there are three services that are desired: 1)Priority Dial Tone - this is a line or endpoint dedicated to emergency calls. 2)Priority Call Setup - this allows an emegency call to be made from any endpoint. 3)Priority Call transit through packet network - this requires interworking existing ISUP high probability of completion call marking with H.323, H.323 Annex M.2, h.246 Annex C, and H.248. An emergency call may be pre-emptive or may just improve the probability of call completion without pre-emption depending on national policy. Authentication issues also need to be worked out. Currently, in the US, this is handled like a calling card authentication. At the Geneva meeting, it was decided that this work was closely related to contribution D.4 from Cicso on reserving resources and also Annex N/H.323 on QOS. Also included were liaison statements from SG11 on QOS for BICC, and an ETSI TIPHON document on signaling end-to-end-qos. All of these items require a method of signaling the desired quality of service. One way of doing this that seems to be common to all requirements is to specify a Service Class parameter and to send this parameter in the various RAS and Call Signaling exchanges. I would like to propose the following Service Class parameter. ServiceClass ::= SEQUENCE { priority CHOICE { emergency, high, normal, low } quality CHOICE ;per TIPHON definition { best, high, medium, bestEffort } } The priority field is used to indicate the importance of the call. This is used not only for assuring that resources can be allocated, but also to improve the probability of completion of the call. The quality field is taken from the ETSI TIPHON QOS Class definitions, and relate to bitrate, codec type, and voice or video quality. High or emergency priority calls may not require best audio quality, medium may be sufficient (even prefered because of the lower bandwidth requirement), while normal priority calls may desire high or best audio quality. The Service Class parameter would then be added to the necessary RAS and Call Signalling messages. At a minimum this would include the ARQ and Setup messages, but might also be applied to others. It is necessary in the ARQ and Setup messages so that High Probability of Completion calls comming into the network from the PSTN can be given priority treatment. For priority dial tone, perhaps the Service Class should be included in the RRQ to indicate the desired priority, once authenticated by the Gatekeeper and confirmed in the RCF, this endpoint could then include that Service Class in subsequent ARQ and Setup messages. Is a token required from the Gatekeeper to indicate that the endpoint has been granted priority status???? For priority call completion, an authentication authority and procedure needs to be defined. One approach is for the call to be made to an access number, the user is then queried for a PIN and the called endpoint number. After authentication, the call would be transfered to the called endpoint. The transfered call would be placed using the Service Class provided by the athentication authority. This would be the same procedure for any calling card call made on the packet network. The Service Class would be based on teh service level agreement between the card user and the provider. In the case of an emergency caller, the SLA would indicate Emergency Priority. How are calling card calls handled on packet networks now???? Is this consistent??? I would appreciate any input that you could provide. Gary -------------------------------------------- Name : Gary A. Thom Company: Delta Information Systems, Inc. Address: 300 Welsh Rd., Bldg 3 Horsham, PA 19044 USA Phone : +1-215-657-5270 x123 Fax : +1-215-657-5273 E-mail : gthom(a)delta-info.com Website: www.delta-info.com -------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 1

Re: The use of statusDeterminationNumber in masterSlaveDeterminat ion
by Mike Nilsson 03 May '01

03 May '01

Frank, I do not see any conflict between the text that you have quoted and the figure. I do not understand how you can say using modulo arithmetic has no effect. For example, 1 - 2 = -1, but 1 - 2 modulo 2^24 is 2^24 - 1. The absolute value of the difference between local and received values can not be used as this would be the same at both ends, hence both would conclude to being the master (or both the slave). Best regards Mike Nilsson -------------------- Mike Nilsson Advanced Video Services > BTexact Technologies > Callisto House, B81 Room 102 pp14 Adastral Park, Martlesham Heath, Ipswich, IP5 3RE, UK Tel: +44 1473 645413 Mobile: +44 7808 635412 Fax: +44 1473 646589 Email: mike.nilsson(a)bt.com BTexact Technologies is a trademark of British Telecommunications plc Registered office: 81 Newgate Street London EC1A 7AJ Registered in England no. 1800000 This electronic message contains information from British Telecommunications plc which may be privileged or confidential. The information is intended to be for the use of the individual(s) or entity named above. If you are not the intended recipient be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited. If you have received this electronic message in error, please notify us by telephone or email (to the numbers or address above) immediately. > -----Original Message----- > From: frank.derks(a)philips.com [SMTP:frank.derks@philips.com] > Sent: Thursday, May 03, 2001 3:23 PM > To: mike.nilsson > Cc: itu-sg16 > Subject: RE: The use of statusDeterminationNumber in > masterSlaveDeterminat ion > > Mike, > > the figure only partly solves the problem. The text that I referred > to does not reflect what is in the figure, so this should be corrected. > > Furthermore, since the values that statusDeterminationNumber can take > on are in the range 0..(2^24-1). The "modulo operation" with 2^24 > has no effect whatsoever. > > It would seem that the real intent is that the _absolute_ value of the > difference between the received statusDeterminationNumber and the > locally generated statusDeterminationNumber determines which party is > to become the master and which party is to becomes the slave. If the > difference is smaller than 2^23 then the party that received the > masterSlaveDetermination message becomes the master. Otherwise it > becomes the slave. In the case that the two numbers are equal, the > result is indeterminate. > > Regards, > > Frank > > > ----------------------------------------------------- > Frank Derks |Tel +31 35 6893238 | > ServWare |Fax +31 35 6891030 | > Philips Business Communications|P.O. Box 32 | > |1200 JD Hilversum | > |The Netherlands | > ----------------------------------------------------| > E-mail: mailto:frank.derks@philips.com | > WWW: http://www.sopho.philips.com | > ----------------------------------------------------- > > > > > > mike.nilsson(a)bt.com on 03-05-2001 16:04:45 > To: Frank Derks/HVS/BE/PHILIPS@EMEA2 > cc: > Subject: RE: The use if statusDeterminationNumber in > masterSlaveDeterminat ion > Classification: > > > Frank, > > The answer is in Figure C.4(v) of H.245. > > Best regards > > Mike Nilsson > > -------------------- > Mike Nilsson > Advanced Video Services > > BTexact Technologies > > > Callisto House, B81 Room 102 pp14 > Adastral Park, Martlesham Heath, Ipswich, IP5 3RE, UK > Tel: +44 1473 645413 > Mobile: +44 7808 635412 > Fax: +44 1473 646589 > Email: mike.nilsson(a)bt.com > > > BTexact Technologies is a trademark of British Telecommunications plc > Registered office: 81 Newgate Street London EC1A 7AJ > Registered in England no. 1800000 > > This electronic message contains information from British > Telecommunications > plc which may be privileged or confidential. The information is intended > to > be for the use of the individual(s) or entity named above. If you are not > the intended recipient be aware that any disclosure, copying, distribution > or use of the contents of this information is prohibited. If you have > received this electronic message in error, please notify us by telephone > or > email (to the numbers or address above) immediately. > > > > -----Original Message----- > > From: Frank Derks [SMTP:frank.derks@PHILIPS.COM] > > Sent: Thursday, May 03, 2001 1:51 PM > > To: ITU-SG16(a)MAILBAG.INTEL.COM > > Subject: The use if statusDeterminationNumber in > > masterSlaveDetermination > > > > C.2.1.4/H.245 states the following: > > > > "If the terminal type numbers are the same, the > statusDeterminationNumbers > > are compared using modulo arithmetic to determine which is master > > > > If both terminals have equal terminalType field values and the > difference > > between statusDetermination field values modulo 2^24 is 0 or 2^23, an > > indeterminate result is obtained" > > > > The first sentence states that "modulo arithmetic" must be used to > compare > > the numbers. I would say that that's a rather vague way of describing > how > > the comparison must be done. Furthermore it does not tell me what the > > result > > must be for a terminal to be determined to be the master! > > > > According to the second sentence, I know how to obtain an indeterminate > > result. So any result that is not any of the two specified values is not > > indeterminate, but I still do not know what the meaning of the result > is. > > "Modulo arithmetic" is, however, introduced, but it is not clear whether > > this is the modulo arithmetic referred to in the first sentence. > > Furthermore, > > what is the significance of a result of 2^23? > > > > I assume that the same rules that apply to the comparison of the > > terminalType > > field apply (i.e. the terminal with the higher value becomes the > master), > > but this is not stated explicitly. > > > > Regards, > > > > Frank > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > For help on this mail list, send "HELP ITU-SG16" in a message to > > listserv(a)mailbag.intel.com > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

Re: The use of statusDeterminationNumber in masterSlaveDeterminat ion
by Frank Derks 03 May '01

03 May '01

Mike, the figure only partly solves the problem. The text that I referred to does not reflect what is in the figure, so this should be corrected. Furthermore, since the values that statusDeterminationNumber can take on are in the range 0..(2^24-1). The "modulo operation" with 2^24 has no effect whatsoever. It would seem that the real intent is that the _absolute_ value of the difference between the received statusDeterminationNumber and the locally generated statusDeterminationNumber determines which party is to become the master and which party is to becomes the slave. If the difference is smaller than 2^23 then the party that received the masterSlaveDetermination message becomes the master. Otherwise it becomes the slave. In the case that the two numbers are equal, the result is indeterminate. Regards, Frank ----------------------------------------------------- Frank Derks |Tel +31 35 6893238 | ServWare |Fax +31 35 6891030 | Philips Business Communications|P.O. Box 32 | |1200 JD Hilversum | |The Netherlands | ----------------------------------------------------| E-mail: mailto:frank.derks@philips.com | WWW: http://www.sopho.philips.com | ----------------------------------------------------- mike.nilsson(a)bt.com on 03-05-2001 16:04:45 To: Frank Derks/HVS/BE/PHILIPS@EMEA2 cc: Subject: RE: The use if statusDeterminationNumber in masterSlaveDeterminat ion Classification: Frank, The answer is in Figure C.4(v) of H.245. Best regards Mike Nilsson -------------------- Mike Nilsson Advanced Video Services > BTexact Technologies > Callisto House, B81 Room 102 pp14 Adastral Park, Martlesham Heath, Ipswich, IP5 3RE, UK Tel: +44 1473 645413 Mobile: +44 7808 635412 Fax: +44 1473 646589 Email: mike.nilsson(a)bt.com BTexact Technologies is a trademark of British Telecommunications plc Registered office: 81 Newgate Street London EC1A 7AJ Registered in England no. 1800000 This electronic message contains information from British Telecommunications plc which may be privileged or confidential. The information is intended to be for the use of the individual(s) or entity named above. If you are not the intended recipient be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited. If you have received this electronic message in error, please notify us by telephone or email (to the numbers or address above) immediately. > -----Original Message----- > From: Frank Derks [SMTP:frank.derks@PHILIPS.COM] > Sent: Thursday, May 03, 2001 1:51 PM > To: ITU-SG16(a)MAILBAG.INTEL.COM > Subject: The use if statusDeterminationNumber in > masterSlaveDetermination > > C.2.1.4/H.245 states the following: > > "If the terminal type numbers are the same, the statusDeterminationNumbers > are compared using modulo arithmetic to determine which is master > > If both terminals have equal terminalType field values and the difference > between statusDetermination field values modulo 2^24 is 0 or 2^23, an > indeterminate result is obtained" > > The first sentence states that "modulo arithmetic" must be used to compare > the numbers. I would say that that's a rather vague way of describing how > the comparison must be done. Furthermore it does not tell me what the > result > must be for a terminal to be determined to be the master! > > According to the second sentence, I know how to obtain an indeterminate > result. So any result that is not any of the two specified values is not > indeterminate, but I still do not know what the meaning of the result is. > "Modulo arithmetic" is, however, introduced, but it is not clear whether > this is the modulo arithmetic referred to in the first sentence. > Furthermore, > what is the significance of a result of 2^23? > > I assume that the same rules that apply to the comparison of the > terminalType > field apply (i.e. the terminal with the higher value becomes the master), > but this is not stated explicitly. > > Regards, > > Frank > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > For help on this mail list, send "HELP ITU-SG16" in a message to > listserv(a)mailbag.intel.com ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0

The use if statusDeterminationNumber in masterSlaveDetermination
by Frank Derks 03 May '01

03 May '01

C.2.1.4/H.245 states the following: "If the terminal type numbers are the same, the statusDeterminationNumbers are compared using modulo arithmetic to determine which is master If both terminals have equal terminalType field values and the difference between statusDetermination field values modulo 2^24 is 0 or 2^23, an indeterminate result is obtained" The first sentence states that "modulo arithmetic" must be used to compare the numbers. I would say that that's a rather vague way of describing how the comparison must be done. Furthermore it does not tell me what the result must be for a terminal to be determined to be the master! According to the second sentence, I know how to obtain an indeterminate result. So any result that is not any of the two specified values is not indeterminate, but I still do not know what the meaning of the result is. "Modulo arithmetic" is, however, introduced, but it is not clear whether this is the modulo arithmetic referred to in the first sentence. Furthermore, what is the significance of a result of 2^23? I assume that the same rules that apply to the comparison of the terminalType field apply (i.e. the terminal with the higher value becomes the master), but this is not stated explicitly. Regards, Frank ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For help on this mail list, send "HELP ITU-SG16" in a message to listserv(a)mailbag.intel.com

1 0