**Session Date/Time:** 22 Jun 2026 16:30 **Will Law:** ...forum today because I do want to get a number of eyes on the subject and I want to -- we talked today and he say "Well, you used your interim slot, that's it." But, in fact, it's not -- it's not really effectively done with this audience. I mean, the audience is great. We're here but I don't think I think with all the confusion, a lot of people are not. **Speaker 2:** Um... Why no Allen is going to be a little late? He said that. Um so, he is aware of it. Uh I Victor is aware of it. I know Ian is aware of it. Um I assume like English -- people do show up late as well. **Will Law:** Okay. **Speaker 2:** So, um... **Will Law:** So, maybe let's start with 5 minutes past instead of our usual on the dot. **Speaker 2:** That's not a terrible idea. Why don't we give it um... I'll give it a few minutes. **Will Law:** Okay. **Speaker 2:** And, you know, I think at some point we'll start because you know I think we'll get through all the trivia. And if um... I think if you get to your your time and you're like this really isn't the set of people that I want to run this by, we can just sort of abort the whole thing. Um... **Will Law:** Oh, I'm happy to do it. I prepared the slides, I worked on it today. **Speaker 2:** No, no, no, no. It's not that I mean we can always punch to next time. Um if you if you look at this and you say um... You know, I mean I think you you probably have a good idea on on who you really want in the room for DTS. And if um... If like nothing, other words, I'm allowing you to set the quorum on this. Okay. I'm going to get started here in a minute and run through all my trivia stuff. And um... If we get a little closer and you're like "You know what? There's just too many people missing that need to see this. Let's just not do it." Okay. Rather than waste everyone's time. Does that make sense? **Will Law:** Yeah. **Speaker 2:** Okay. I know Magnus is on vacation this week so he will not be here. All right, I'm going to start running through admin trivia. Um welcome to the uh 22 June Mock Virtual Interim. Hope everyone has recovered from the London trip. Uh for those of you who just got on, um this has not gone well regarding the track stuff and so on. So, I'm going to run through admin trivia here and then I'm going to give Will the option on whether he wants to continue if he feels he has a quorum for people who need to see DTS stuff or um it's just not a good enough turnout. Although I see people joining right now. Uh we're getting closer to our typical virtual turnout. Uh Magnus will not be here today, he's on vacation. I know that Ian is on his way and or at least he said he was going to be here, and Allen said he was going to be here but late. So, you can consider that in your in your thing as well, Will. This is the IETF note well. Uh I don't think anyone here is new to this, but this just talks about some of the legalities uh regarding your participation with IETF. If for some reason this is new to you, scan the QR code or type IETF note well into a search engine and read up on it. As always, we're using MeetEcho. If you want to talk, join the mic queue or participate in a show of hands, use the raise hand button at the bottom of your screen. Um in general, keep your audio and video off. Please use a headset if you possibly can. The echo cancellation properties of this tool are not great. And unmute has a lag of about 1 second so if you're going to talk, uh unmute yourself a little bit early. If you're in a back and forth conversation, just leave your audio on assuming that you're using a headset. Uh otherwise, just stay muted until it's time to talk. We have another number of upcoming dates. Uh Magnus did not put a time limit on it but he did publish some minutes for the London meeting so please take a look at that and make -- those are AI generated so um you may have heard sometimes AI outputs you may have heard that sometimes AI AI output is inaccurate so you might want to take a look at it. Make sure something horrible hasn't been attributed to you. Uh Magnus did take a look at it. It's not completely unsanitized but uh only you know what you meant. Uh there's a call out for members of the auth design team. That call concludes on the 26th of June, which I think is Friday. So, uh please email the chairs before then if you're interested. I put out a venue poll on July 5th uh or rather due July 5th to discuss the possible locations for our uh October hybrid interim somewhere in North America. No one uh expressed a serious concern about any of the locations except for Costa Rica, so that is not on the poll. Um if you actually have a serious concern, please email the chairs and we'll take that into consideration. Otherwise, it's kind of a beauty contest. The choices are excited, neutral, and and annoyed by location. There's no criteria for those things. If you're just tired of going to Seattle or or say uh because we've been there several times, you're welcome to say uh annoyed. Um I did uh due to operator failure uh not include Atlanta in the initial thing. It's been updated. If you've already um submitted your uh preferences and wish to express a preference about Atlanta, just please email me personally and I'll update the the spreadsheet manually to to reflect your input. Um sorry for that confusion. And then, of course, uh on the July 6th, which is the draft deadline, we're going to have another virtual interim that presumably will be about um MoqTI issues unless this today's meeting goes sideways. And then, of course, we're leading into Vienna. The the preliminary agenda is out for Vienna. We have the late Friday evening slot as one of our three slots. We will almost certainly use that for our um non-MoqTI adopted drafts uh for for various reasons. So, um I strongly encourage if you're interested in those, I strongly encourage you to stay through the end of the week in Vienna. Uh I forgot to update this slide. This is not accurate at all. Sorry. I'm just going to stop sharing it. Um you're in the admin trivia portion. I see we have a pretty good turnout. Um so we're just going to give Will the balance of the time and then um if there is any balance of time, then the MoqTI editors will do their usual thing. Would anyone like to bash the agenda? Okay. Um hearing no one, uh Will, I would judge this is a pretty good turnout. Looks like people have joined. **Will Law:** Yeah, this is great. Everyone's here, let's go. Okay. Thank you for dealing with with with various uh chair failures and data tracker issues that have led us to this confusion. I'm going to share screen. Screen share... Yes... Okay. So, thank you very much. So, this is a topic that was scheduled for London but got pushed out of the agenda, so we're uh we're grateful to have some time at this interim uh to present it. This is dynamic track switching for MOQT relays. Just a a brief summary of the timeline. It was first proposed in Boulder. Uh we established a draft as a design team. Uh Cisco built a POC uh that was demoed by Suhas. At Shenzhen, we did a presentation. Uh May 11th at the IETF mock interim, we had a vote. We decided to include it in mock. Uh Nokia have built a mock since then and we now have a PR that's open, 1638. So, this call today is about trying to resolve five open issues on that PR 1638 so that we can get it integrated. I wanted to show you a brief video just to show mock uh uh DTS in action. This is from Nokia. Yu You is not on the call today, so I he added some annotation uh which you can read. So, he's got three media tracks in a set: 500, 1500, and 3 megs. And the relay's receiving all of them and only forwarding one. So, this is the the default sort of behavior of DTS. And it's a little hard to see on his overhead is track overlay, but you do see the width and the height. And then, he's able to simulate throughput. I don't know if he's doing that for real or if it's only actually a simulation, but then you watch the video changing. Uh and it's doing it by toggling the forward state. And his switches are smooth and continuous, which is good and what we would expect from the solution. And then, he's able to switch it off completely. So, the items are still assigned to a set but they're no longer being actively switched. And you'll notice it keeps playing the 1080p feed even though he's uh giving it different bitrate input. Then, he switches switching back on, and then it resumes and it drop down to 720 immediately. Uh and there's a little bit more of this. He does a time band bursty oscillation. So, this is where you're getting uh highly aggressive uh throughput changes. Uh and it's going to basically be switching at close to every segment boundary, which users wouldn't want, but that's still preferred if, in fact, your bandwidth is truly uh varying at that rate. But it showed the ability of it to cope with uh higher frequency of changes. Okay, I'm going to try to skip to the end to save some time. Okay. So, we did make one change. The PR came up, there was comments there, and there was one comment that activate switching used to be a binary flag, right? So, notice activate switching when you you registered your first track was zero, then it was zero, and then your last track was one. But it was pointed out that you can't actually guarantee the order of arrivals of these. So, this 1080p, even though you sent it first or sent it last, might have arrived second. So, that you would then inadvertently switch on your your your switching between... --- **Session Date/Time:** 22 Jun 2026 16:30 **Will Law:** ...forum today because I do want to get a number of eyes on the subject and I want to -- we talked today and he say "Well, you used your interim slot, that's it." But, in fact, it's not -- it's not really effectively done with this audience. I mean, the audience is great. We're here but I don't think I think with all the confusion, a lot of people are not. **Speaker 2:** Um... Why no Allen is going to be a little late? He said that. Um so, he is aware of it. Uh I Victor is aware of it. I know Ian is aware of it. Um I assume like English -- people do show up late as well. **Will Law:** Okay. **Speaker 2:** So, um... **Will Law:** So, maybe let's start with 5 minutes past instead of our usual on the dot. **Speaker 2:** That's not a terrible idea. Why don't we give it um... I'll give it a few minutes. **Will Law:** Okay. **Speaker 2:** And, you know, I think at some point we'll start because you know I think we'll get through all the trivia. And if um... I think if you get to your your time and you're like this really isn't the set of people that I want to run this by, we can just sort of abort the whole thing. Um... **Will Law:** Oh, I'm happy to do it. I prepared the slides, I worked on it today. **Speaker 2:** No, no, no, no. It's not that I mean we can always punch to next time. Um if you if you look at this and you say um... You know, I mean I think you you probably have a good idea on on who you really want in the room for DTS. And if um... If like nothing, other words, I'm allowing you to set the quorum on this. Okay. I'm going to get started here in a minute and run through all my trivia stuff. And um... If we get a little closer and you're like "You know what? There's just too many people missing that need to see this. Let's just not do it." Okay. Rather than waste everyone's time. Does that make sense? **Will Law:** Yeah. **Speaker 2:** Okay. I know Magnus is on vacation this week so he will not be here. All right, I'm going to start running through admin trivia. Um welcome to the uh 22 June Mock Virtual Interim. Hope everyone has recovered from the London trip. Uh for those of you who just got on, um this has not gone well regarding the track stuff and so on. So, I'm going to run through admin trivia here and then I'm going to give Will the option on whether he wants to continue if he feels he has a quorum for people who need to see DTS stuff or um it's just not a good enough turnout. Although I see people joining right now. Uh we're getting closer to our typical virtual turnout. Uh Magnus will not be here today, he's on vacation. I know that Ian is on his way and or at least he said he was going to be here, and Allen said he was going to be here but late. So, you can consider that in your in your thing as well, Will. This is the IETF note well. Uh I don't think anyone here is new to this, but this just talks about some of the legalities uh regarding your participation with IETF. If for some reason this is new to you, scan the QR code or type IETF note well into a search engine and read up on it. As always, we're using MeetEcho. If you want to talk, join the mic queue or participate in a show of hands, use the raise hand button at the bottom of your screen. Um in general, keep your audio and video off. Please use a headset if you possibly can. The echo cancellation properties of this tool are not great. And unmute has a lag of about 1 second so if you're going to talk, uh unmute yourself a little bit early. If you're in a back and forth conversation, just leave your audio on assuming that you're using a headset. Uh otherwise, just stay muted until it's time to talk. We have another number of upcoming dates. Uh Magnus did not put a time limit on it but he did publish some minutes for the London meeting so please take a look at that and make -- those are AI generated so um you may have heard sometimes AI outputs you may have heard that sometimes AI AI output is inaccurate so you might want to take a look at it. Make sure something horrible hasn't been attributed to you. Uh Magnus did take a look at it. It's not completely unsanitized but uh only you know what you meant. Uh there's a call out for members of the auth design team. That call concludes on the 26th of June, which I think is Friday. So, uh please email the chairs before then if you're interested. I put out a venue poll on July 5th uh or rather due July 5th to discuss the possible locations for our uh October hybrid interim somewhere in North America. No one uh expressed a serious concern about any of the locations except for Costa Rica, so that is not on the poll. Um if you actually have a serious concern, please email the chairs and we'll take that into consideration. Otherwise, it's kind of a beauty contest. The choices are excited, neutral, and and annoyed by location. There's no criteria for those things. If you're just tired of going to Seattle or or say uh because we've been there several times, you're welcome to say uh annoyed. Um I did uh due to operator failure uh not include Atlanta in the initial thing. It's been updated. If you've already um submitted your uh preferences and wish to express a preference about Atlanta, just please email me personally and I'll update the the spreadsheet manually to to reflect your input. Um sorry for that confusion. And then, of course, uh on the July 6th, which is the draft deadline, we're going to have another virtual interim that presumably will be about um MoqTI issues unless this today's meeting goes sideways. And then, of course, we're leading into Vienna. The the preliminary agenda is out for Vienna. We have the late Friday evening slot as one of our three slots. We will almost certainly use that for our um non-MoqTI adopted drafts uh for for various reasons. So, um I strongly encourage if you're interested in those, I strongly encourage you to stay through the end of the week in Vienna. Uh I forgot to update this slide. This is not accurate at all. Sorry. I'm just going to stop sharing it. Um you're in the admin trivia portion. I see we have a pretty good turnout. Um so we're just going to give Will the balance of the time and then um if there is any balance of time, then the MoqTI editors will do their usual thing. Would anyone like to bash the agenda? Okay. Um hearing no one, uh Will, I would judge this is a pretty good turnout. Looks like people have joined. **Will Law:** Yeah, this is great. Everyone's here, let's go. Okay. Thank you for dealing with with with various uh chair failures and data tracker issues that have led us to this confusion. I'm going to share screen. Screen share... Yes... Okay. So, thank you very much. So, this is a topic that was scheduled for London but got pushed out of the agenda, so we're uh we're grateful to have some time at this interim uh to present it. This is dynamic track switching for MOQT relays. Just a a brief summary of the timeline. It was first proposed in Boulder. Uh we established a draft as a design team. Uh Cisco built a POC uh that was demoed by Suhas. At Shenzhen, we did a presentation. Uh May 11th at the IETF mock interim, we had a vote. We decided to include it in mock. Uh Nokia have built a mock since then and we now have a PR that's open, 1638. So, this call today is about trying to resolve five open issues on that PR 1638 so that we can get it integrated. I wanted to show you a brief video just to show mock uh uh DTS in action. This is from Nokia. Yu You is not on the call today, so I he added some annotation uh which you can read. So, he's got three media tracks in a set: 500, 1500, and 3 megs. And the relay's receiving all of them and only forwarding one. So, this is the the default sort of behavior of DTS. And it's a little hard to see on his overhead is track overlay, but you do see the width and the height. And then, he's able to simulate throughput. I don't know if he's doing that for real or if it's only actually a simulation, but then you watch the video changing. Uh and it's doing it by toggling the forward state. And his switches are smooth and continuous, which is good and what we would expect from the solution. And then, he's able to switch it off completely. So, the items are still assigned to a set but they're no longer being actively switched. And you'll notice it keeps playing the 1080p feed even though he's uh giving it different bitrate input. Then, he switches switching back on, and then it resumes and it drop down to 720 immediately. Uh and there's a little bit more of this. He does a time band bursty oscillation. So, this is where you're getting uh highly aggressive uh throughput changes. Uh and it's going to basically be switching at close to every segment boundary, which users wouldn't want, but that's still preferred if, in fact, your bandwidth is truly uh varying at that rate. But it showed the ability of it to cope with uh higher frequency of changes. Okay, I'm going to try to skip to the end to save some time. Okay. So, we did make one change. The PR came up, there was comments there, and there was one comment that activate switching used to be a binary flag, right? So, notice activate switching when you you registered your first track was zero, then it was zero, and then your last track was one. But it was pointed out that you can't actually guarantee the order of arrivals of these. So, this 1080p, even though you sent it first or sent it last, might have arrived second. So, that you would then inadvertently switch on your your your switching between... --- **Session Date/Time:** 22 Jun 2026 16:30 **Will Law:** ...forum today because I do want to get a number of eyes on the subject and I want to -- we talked today and he say "Well, you used your interim slot, that's it." But, in fact, it's not -- it's not really effectively done with this audience. I mean, the audience is great. We're here but I don't think I think with all the confusion, a lot of people are not. **Speaker 2:** Um... Why no Allen is going to be a little late? He said that. Um so, he is aware of it. Uh I Victor is aware of it. I know Ian is aware of it. Um I assume like English -- people do show up late as well. **Will Law:** Okay. **Speaker 2:** So, um... **Will Law:** So, maybe let's start with 5 minutes past instead of our usual on the dot. **Speaker 2:** That's not a terrible idea. Why don't we give it um... I'll give it a few minutes. **Will Law:** Okay. **Speaker 2:** And, you know, I think at some point we'll start because you know I think we'll get through all the trivia. And if um... I think if you get to your your time and you're like this really isn't the set of people that I want to run this by, we can just sort of abort the whole thing. Um... **Will Law:** Oh, I'm happy to do it. I prepared the slides, I worked on it today. **Speaker 2:** No, no, no, no. It's not that I mean we can always punch to next time. Um if you if you look at this and you say um... You know, I mean I think you you probably have a good idea on on who you really want in the room for DTS. And if um... If like nothing, other words, I'm allowing you to set the quorum on this. Okay. I'm going to get started here in a minute and run through all my trivia stuff. And um... If we get a little closer and you're like "You know what? There's just too many people missing that need to see this. Let's just not do it." Okay. Rather than waste everyone's time. Does that make sense? **Will Law:** Yeah. **Speaker 2:** Okay. I know Magnus is on vacation this week so he will not be here. All right, I'm going to start running through admin trivia. Um welcome to the uh 22 June Mock Virtual Interim. Hope everyone has recovered from the London trip. Uh for those of you who just got on, um this has not gone well regarding the track stuff and so on. So, I'm going to run through admin trivia here and then I'm going to give Will the option on whether he wants to continue if he feels he has a quorum for people who need to see DTS stuff or um it's just not a good enough turnout. Although I see people joining right now. Uh we're getting closer to our typical virtual turnout. Uh Magnus will not be here today, he's on vacation. I know that Ian is on his way and or at least he said he was going to be here, and Allen said he was going to be here but late. So, you can consider that in your in your thing as well, Will. This is the IETF note well. Uh I don't think anyone here is new to this, but this just talks about some of the legalities uh regarding your participation with IETF. If for some reason this is new to you, scan the QR code or type IETF note well into a search engine and read up on it. As always, we're using MeetEcho. If you want to talk, join the mic queue or participate in a show of hands, use the raise hand button at the bottom of your screen. Um in general, keep your audio and video off. Please use a headset if you possibly can. The echo cancellation properties of this tool are not great. And unmute has a lag of about 1 second so if you're going to talk, uh unmute yourself a little bit early. If you're in a back and forth conversation, just leave your audio on assuming that you're using a headset. Uh otherwise, just stay muted until it's time to talk. We have another number of upcoming dates. Uh Magnus did not put a time limit on it but he did publish some minutes for the London meeting so please take a look at that and make -- those are AI generated so um you may have heard sometimes AI outputs you may have heard that sometimes AI AI output is inaccurate so you might want to take a look at it. Make sure something horrible hasn't been attributed to you. Uh Magnus did take a look at it. It's not completely unsanitized but uh only you know what you meant. Uh there's a call out for members of the auth design team. That call concludes on the 26th of June, which I think is Friday. So, uh please email the chairs before then if you're interested. I put out a venue poll on July 5th uh or rather due July 5th to discuss the possible locations for our uh October hybrid interim somewhere in North America. No one uh expressed a serious concern about any of the locations except for Costa Rica, so that is not on the poll. Um if you actually have a serious concern, please email the chairs and we'll take that into consideration. Otherwise, it's kind of a beauty contest. The choices are excited, neutral, and and annoyed by location. There's no criteria for those things. If you're just tired of going to Seattle or or say uh because we've been there several times, you're welcome to say uh annoyed. Um I did uh due to operator failure uh not include Atlanta in the initial thing. It's been updated. If you've already um submitted your uh preferences and wish to express a preference about Atlanta, just please email me personally and I'll update the the spreadsheet manually to to reflect your input. Um sorry for that confusion. And then, of course, uh on the July 6th, which is the draft deadline, we're going to have another virtual interim that presumably will be about um MoqTI issues unless this today's meeting goes sideways. And then, of course, we're leading into Vienna. The the preliminary agenda is out for Vienna. We have the late Friday evening slot as one of our three slots. We will almost certainly use that for our um non-MoqTI adopted drafts uh for for various reasons. So, um I strongly encourage if you're interested in those, I strongly encourage you to stay through the end of the week in Vienna. Uh I forgot to update this slide. This is not accurate at all. Sorry. I'm just going to stop sharing it. Um you're in the admin trivia portion. I see we have a pretty good turnout. Um so we're just going to give Will the balance of the time and then um if there is any balance of time, then the MoqTI editors will do their usual thing. Would anyone like to bash the agenda? Okay. Um hearing no one, uh Will, I would judge this is a pretty good turnout. Looks like people have joined. **Will Law:** Yeah, this is great. Everyone's here, let's go. Okay. Thank you for dealing with with with various uh chair failures and data tracker issues that have led us to this confusion. I'm going to share screen. Screen share... Yes... Okay. So, thank you very much. So, this is a topic that was scheduled for London but got pushed out of the agenda, so we're uh we're grateful to have some time at this interim uh to present it. This is dynamic track switching for MOQT relays. Just a a brief summary of the timeline. It was first proposed in Boulder. Uh we established a draft as a design team. Uh Cisco built a POC uh that was demoed by Suhas. At Shenzhen, we did a presentation. Uh May 11th at the IETF mock interim, we had a vote. We decided to include it in mock. Uh Nokia have built a mock since then and we now have a PR that's open, 1638. So, this call today is about trying to resolve five open issues on that PR 1638 so that we can get it integrated. I wanted to show you a brief video just to show mock uh uh DTS in action. This is from Nokia. Yu You is not on the call today, so I he added some annotation uh which you can read. So, he's got three media tracks in a set: 500, 1500, and 3 megs. And the relay's receiving all of them and only forwarding one. So, this is the the default sort of behavior of DTS. And it's a little hard to see on his overhead is track overlay, but you do see the width and the height. And then, he's able to simulate throughput. I don't know if he's doing that for real or if it's only actually a simulation, but then you watch the video changing. Uh and it's doing it by toggling the forward state. And his switches are smooth and continuous, which is good and what we would expect from the solution. And then, he's able to switch it off completely. So, the items are still assigned to a set but they're no longer being actively switched. And you'll notice it keeps playing the 1080p feed even though he's uh giving it different bitrate input. Then, he switches switching back on, and then it resumes and it drop down to 720 immediately. Uh and there's a little bit more of this. He does a time band bursty oscillation. So, this is where you're getting uh highly aggressive uh throughput changes. Uh and it's going to basically be switching at close to every segment boundary, which users wouldn't want, but that's still preferred if, in fact, your bandwidth is truly uh varying at that rate. But it showed the ability of it to cope with uh higher frequency of changes. Okay, I'm going to try to skip to the end to save some time. Okay. So, we did make one change. The PR came up, there was comments there, and there was one comment that activate switching used to be a binary flag, right? So, notice activate switching when you you registered your first track was zero, then it was zero, and then your last track was one. But it was pointed out that you can't actually guarantee the order of arrivals of these. So, this 1080p, even though you sent it first or sent it last, might have arrived second. So, that you would then inadvertently switch on your your your switching between...