In conjunction with Super Bowl LX, Comcast’s Xfinity announced the launch of what they call “RealTime4K”, a new ultra-low-latency technology with a 30 Mbps bitrate supporting Dolby Vision HDR and Dolby Atmos, compatible with an Xfinity X1 XG1v4 or Xi6 TV Box, or an XiOne streaming TV Box for Xfinity Flex. Comcast is positioning RealTime4K as a 4K delivery architecture designed specifically for premium live sports and optimized for both speed and visual fidelity. Unlike traditional 4K streams that rely heavily on compression, the technology is engineered to reduce latency while maintaining high-bitrate video and immersive audio formats. While the brand name to consumers uses the term 4K, it’s important to note that it is not native 4K and that Comcast’s source feed is 1080p HDR.

Comcast’s RealTime4K uses DASH and HLS to stream to set-top boxes, and via the Xfinity Stream app, compatible customer-owned streaming devices (Xumo Stream Box, Apple TV, Fire TV, Roku, Samsung and LG TVs) can also get the 30 Mbps stream but without the ultra-low-latency functionality. Comcast set-top boxes further use low-latency DASH (LL-DASH) to remove delays introduced by segment packaging and client-side buffers.

For the encoding pipeline, Comcast uses HEVC and Dolby Vision Profile 8.1, with a bitrate ladder that caps at 30 Mbps and supports full 4K resolution on both the first and second rungs. And since last year’s Super Bowl, Comcast has integrated the latest Dolby Vision improvements into its encoding pipeline. For audio encoding, Comcast RealTime4K always includes Dolby Atmos, natively produced when available from the content provider and, otherwise, upmixed by Comcast. Comcast encodes Atmos at 768 Kbps and delivers it as DD+JOC.

For Super Bowl LX, Comcast partnered with NBCUniversal and used a JPEG-XS source feed. Typical 4K live events are compressed to 50-70 Mbps using HEVC before being sent to distributors. Using JPEG-XS at over 300 Mbps allowed Comcast to avoid a generation of HEVC encoding, significantly improving picture quality and reducing latency by about 5 seconds in the video production pipeline.

The core of Comcast’s RealTime 4K video pipeline is a DASH live ingest, powered distribution transcoder, and CMAF linear origin. The transcoder accepts JPEG-XS as input (or HEVC mezzanine when JPEG-XS isn’t available) and generates all needed renditions while minimizing overall delay. The transcoder publishes each chunk of media, as it is encoded, to the CMAF linear origin. The origin provides access to DASH manifests and segments to both the just-in-time packager (JITP) for live playback and Comcast’s Cloud DVR system. Comcast has partnered with MediaKind for transcoding while building its own CMAF linear origin and JITP. For Super Bowl LX, Comcast used its on-premises CDN to deliver the RealTime4K feed, but also uses the same LL-DASH video architecture to power partner systems using public CDNs such as Akamai and CloudFront.

Beyond the architectural claims, Comcast also put RealTime4K into a live, high-stakes environment during a full day of Olympics and Super Bowl coverage, plus streaming coverage on Peacock, making Sunday, February 8, the most-trafficked day ever for video streaming on Comcast’s network. According to internal testing Comcast conducted during the event, the RealTime4K feed on Xfinity delivered latency that was between 9 and 49 seconds ahead of vMVPD streaming services, even as the network experienced its most-trafficked day for video streaming to date, driven by a mix of IP video streams (including the RealTime4K feed) and streaming on Peacock and other platforms. During my testing of the Super Bowl LX stream, I was unable to test Comcast’s RealTime4K latency myself, as I am not in Comcast’s footprint; otherwise, I would have included them in my latency chart.

As of today, Comcast RealTime4K technology is free for all customers, with the primary limitation being the hardware requirements for the ultra-low-latency verison of the stream. For customers who do not currently have compatible hardware, the company is offering device swaps to 4K-enabled Xfinity equipment at no additional cost. Customers can also visit a nearby Xfinity store to exchange their existing X1 TV box for a 4K-capable one.

Comcast is positioning RealTime4K as the preferred delivery model for live 4K events going forward, not just for showcase events like the Super Bowl, and is already in talks with other programming partners to bring this technology to their live 4K events this year. The company has also emphasized its ongoing commitment to continuous network improvement, focusing on further optimizing delivery, throughput, and video pipelines to push the limits of video quality, latency, and immersive live-viewing performance.

If you have had an opportunity to check out the RealTime4K tech at your home, please feel free to share your experience in the comments. I’ll be hands-on with the technology and offering soon, and will provide updates to this post once I see it in person.

Netskrt Systems has carved out a meaningful foothold in the global streaming video market, particularly tier-one live events such as NFL football games, supporting both TNF on Prime Video and the recent Super Bowl on Peacock. It has done this in a manner unlike most of its competitors, focusing on broad, deep deployment of pure software POP instances that reduce its underlying costs. The cost factor is the key, since historically we have seen CDN vendors grow capacity at the risk of burning a lot of cash.

The net result, the company tells me, is the ability to operate profitably under the demanding price umbrellas imposed by global streaming platforms. And this does show up in its numbers. Netskrt has built far more capacity and generated more revenue with less invested capital than its CDN peers, at its current size. With about $30 million in invested capital, Netskrt expects to exceed a 1:1 capital-to-revenue ratio in 2026 and a 1:4 capital-to-capacity ratio. Conventional CDNs typically operate closer to a higher multiple, but few disclose the ratios publicly.

Netskrt informs me that its current “steady state” capacity is about 65 Tbps, but notes that because software instances can be spun up when and where required, whether on bare metal, virtual machines, or containers, the effective capacity that can be instantiated in 24 to 48 hours is substantially greater. In fact, when it wants to, Netskrt said it can even spin up capacity in cloud-based spot instances in minutes.

This approach, which the company likens to a software-defined CDN, gives Netskrt considerable flexibility while also taking a sledgehammer to capital costs. Further, it’s a stratified infrastructure. Where Netskrt sees persistent, long-lasting demand for capacity, it can deploy iron to meet that demand in a manner that leans more toward CapEx than OpEx. Where it sees the reverse—in particular, the bleeding edge of spiky demand curves associated with live sports that are inherently seasonal, it can lean in the opposite direction. Executing this is more than just a business strategy; Netskrt says it requires CDN technology capable of positioning and repositioning content, as well as live-streaming POPs, in response to a complex array of real-time conditions.

Roughly half of Netskrt’s capacity is embedded in last-mile ISP networks, with the balance allocated to its mid- and global tiers. From a geographic perspective, Netskrt now reaches across North America, South America, Europe and regions in APAC. Netskrt’s current growth trajectory, which has picked up significantly over the last year, will see it reach 150 Tbps by the end of 2026. Their partnerships with large network and bare metal suppliers like Lumen enable them to ramp up to these levels quite quickly.

The company recently conducted a survey with professionals from 55 global ISPs to better understand how major events impact network performance. You can check out the results from that study here.

I’m testing DAZN’s stream of Super Bowl LX, available to NFL Game Pass subscribers outside the US for just £0.99, and the stream looks great. DAZN is taking the NBC international feed in 1080p at 59.94 fps HLG with 5.1, and streaming it in 1080p HDR, not upscaled 4K. I am streaming the DAZN feed in the U.S. using their Swedish app, with their help. Here’s details on the encoding specs:

• The HDR10 ABR ladder peaks at 1080p 59.94fps 8mbps HEVC main10 level 4.1. The HDR10 ladder has 29.97fps in the lower profiles under 3 Mbps.
• The SDR ABD ladder peaks at 1080p59.94 8mbps AVC high profile level 4.2. The SDR ladder has 29.97fps in the lower profiles under 3 Mbps.
• Surround sound in Dolby 5.1: Two EAC-3 profiles at 256kbps and 192kbps
• Stereo: Two AAC-LC profiles in 128kbps and 64kbps

DAZN is acquiring NBC’s feeds for the pre-game, game, halftime and post-game coverage in HDR 5.1 and SDR 5.1 via Encompass in Atlanta, which are then on-passed to DAZN’s regional production facilities worldwide for German, Spanish, Portuguese, Italian, French, and Japanese commentary, and delivered to select local markets via the DAZN app. DAZN’s playout facility uses Amagi for real-time graphics, promos, and ad insertion and the OTT streams are generated by M2A Media and Mediakind in 1080p 59.94fps HDR10 with Dolby 5.1 and 1080p 59.94fps SDR with stereo.

Akamai, CloudFront, and Fastly are delivering the stream across 200+ territories, with DAZN’s monitoring facilities in Leeds, Bangor and Hyderabad monitoring the feeds end-to-end.

Thanks to DAZN for setting up my account so I could watch the stream and test across devices.

*The photo is taken with my iPhone, and does not represent the actual quality of the video stream that viewers receive.

I’ve been testing the Super Bowl LX stream on Sunday, starting with the pre-game stream at 1pm, across more than 25 devices and platforms, documenting video quality, latency, and other technical metrics. You can jump here for my latest comments during the game. (2025 Super Bowl blog post here)

During the game, I am monitoring Reddit boards for Peacock, Fire TV, YouTube TV, Roku, and others, as well as Twitter hashtags, to see what viewers are saying about their streaming quality. I’m also talking to a few ISPs in the U.S. who provide me with details on the traffic they are seeing across their networks. Jump here for a list of all the platforms and devices I am testing.

[And that’s a wrap! While it will be a few days before we have detailed viewership numbers, NBC Sports and Peacock executed what I would consider a near-perfect Super Bowl stream. And it’s important to highlight that while producing a Super Bowl is already hard work, NBC Sports did so while also producing the Winter Olympics, with 17 hours of programming straight. Kudos to the entire NBCU/Peacock team. Many will get no rest as a week from today, NBC Sports will produce the NBA All-Star Weekend onsite in Los Angeles.]

NBC Sports’ stream of Super Bowl LX requires a Peacock Premium plan and is available on the NBC Sports website and app, with authentication via pay-TV credentials. Peacock doesn’t offer free trials, so anyone who wants to stream the Super Bowl on Peacock will need to pay for an account or, in the U.S., have YouTube TV, Sling TV, DirecTV,  or Hulu + Live TV. Fubo is currently in a carriage dispute with NBCU, so the game won’t be on Fubo. The game is also available via OTA and will be broadcast on Telemundo and Universo. Outside the U.S., NFL Game Pass is offered via DAZN, and users can stream the Super Bowl for just £0.99. If there is anything you want me to test during the game, please put it in the comments on this LinkedIn Post.

Tech Specs
The Peacock stream is in “upscaled” 4K HDR; it is not native 4K, and I see many news outlets reporting it is in “true 4K HDR,” implying it is being captured in 4K when it isn’t. Also, this is not the “first time” the Super Bowl has been in upscaled 4K. I understand why some people are reporting that online, since, unlike the broadcast world, where there is a standard, streamers all define 4K differently. The NBC Sports press release was very clear when it said, “This marks the first time a Super Bowl and Olympic Games will be presented in 4K HDR on the NBC broadcast network and the Peacock streaming service.” It’s the first time on NBC’s platform that BOTH events are offered in upscaled 4K HDR, not the first time an “upscaled” 4K Super Bowl stream has been offered.

NBC Sports has deployed 22 mobile units from NEP Group, 145 cameras, 130 microphones, 75 miles of cable, and a team of more than 700 employees on-site. NBC’s contribution feed is 1080p 59.94 fps PQ with 5.1. and international partners are getting the same, but in HLG. Dolby is also upscaling the audio to Dolby Atmos, but not all devices support 4K and Atmos. You can see a list of all currently supported devices here. Akamai, CloudFront, Fastly, Comcast, Google Media CDN, and Netskrt are delivering the video for Peacock, and Akamai, CloudFront, and Fastly are delivering the video for DAZN outside the U.S.

Encoding:

• MPEG-DASH stream using CMAF-packaged fragmented MP4 with AES-CTR Common Encryption and multi-DRM (Widevine + PlayReady), protected by session-scoped CDN access tokens
• MPD manifest provides a 2-hour DVR window
• HD stream encoding bitrate ladder: (H.264)
  • 512×288 ~350 kb/s
  • 768×432 ~860 kb/s
  • 960×540 ~1.85 Mb/s
  • 960×540 ~3.0 Mb/s
  • 1280×720 ~4.8 Mb/s
  • 1920×1080 ~7.8 Mb/s
  • 1920×1080 ~10 Mb/s
  • Audio: AAC-LC stereo 48 kHz ~128 kb/s
  • Audio: E-AC3 (Dolby Digital Plus) 5.1 ~384 kb/s
• 4k stream encoding bitrate ladder: (HEVC)
  • 640×360 ~500 kb/s
  • 960×540 ~1.0 Mb/s
  • 1280×720 ~2.5 Mb/s(59.94 fps)
  • 1920×1080~5.8 Mb/s(59.94 fps)
  • 3840×2160 ~10.0 Mb/s(59.94 fps)
  • 3840×2160 ~13.0 Mb/s(59.94 fps)
  • Audio: AAC-LC stereo 48 kHz ~128 kb/s
  • Audio: E-AC3+JOC Dolby Atmos 5.1.4 ~640 kb/s

Latency Testing Results
For latency testing, I ran the test 10x per device and app/platform and compared the results to the OTA feed from two antennas. Note that many factors affect the latency viewers experience, so my experience may not be representative of other users. Here’s the latency I saw across devices and platforms:

• Testing across three different illegal IPTV services averaged 58 seconds behind the OTA feed
• Sling TV app on Fire TV (ethernet): 59.4 seconds average behind the OTA feed
• Hulu+ Live TV app on Fire TV (ethernet) averaged 34.2 seconds behind the OTA feed
• DIRECTV on Fire TV (ethernet) averaged 52.8 seconds behind the OTA feed
• YouTube TV on Fire TV (ethernet) averaged 28.3 seconds behind the OTA feed
• NFL+: Didn’t test

*I’ll add latency testing from YouTube TV, Hulu + Live TV, DIRECTV and NFL+ shortly.

Live Updates During The Game

10:37pm: NBCU says they had a rebuffer rate of 0.07% for the Peacock stream.

10:15pm: With the 2-minute warning, NBC Sports and Peacock executed what I would consider a near-perfect Super Bowl stream. My thanks to NBC Sports for help with some of the tech specs, and to others who provided details about their experience.

9:22pm: It’s the end of the third quarter, and all is still looking good with Peacock’s stream. Two ISPs tell me traffic on their network looks good, with an average bitrate of about 8.5 Mbps. It’s not record traffic for them, though, nor would we expect it to be, since the Peacock stream is not free, as it was last year on Tubi and FOX.

8:28pm: It seems that bad bunny is confusing Peacock’s English subtitling option.

8:20pm: I love that Peacock is giving viewers the option to catch up on key plays if you don’t want to watch the halftime show.

8:07pm: Added latency testing results across three different illegal IPTV services, which averaged 58 seconds behind the OTA feed. Sling TV app on Fire TV (ethernet) averaged 59.4 seconds behind the OTA feed. Hulu+ Live TV app on Fire TV (ethernet) averaged 34.2 seconds behind the OTA feed

7:35pm: Across Twitter, monitoring Peacock hashtags since kickoff, I see a dozen complaints about stream quality, but none have provided any useful details. Complaints are to be expected for any live stream, but no major issues are being reported in any large volume. The stream is looking great. I do see one user complaining about getting a message saying they need to update their app, and says that Peacock should not be rolling out app updates during the Super Bowl, which they did not do. Many complaints during live events are “user issues” rather than problems with the stream itself.

7:11pm: DAZN’s stream of Super Bowl LX, available to NFL Game Pass subscribers outside the US for just £0.99, looks good. DAZN is taking the NBC international feed in 1080p at 59.94 fps HLG with 5.1, and streaming it in 1080p HDR, not upscaled 4K. I am streaming the DAZN feed in the U.S. using their Swedish app, with their help. You can see the tech specs and full review here.

6:54pm: Peacock stream looks VERY good across Fire TV, Roku, Apple TV, and iOS devices for me. Colors are perfect, and the upscaled 4K looks great and is not washed out.

6:40pm: I’m testing Peacock’s Super Bowl LX stream over a SpaceX Starlink Mini, and it’s not great. I’m getting 265 Mbps down and 22 ms latency. On an Amazon Fire TV Stick 4K Max (2nd Gen, AFTKRT), there is significant buffering, and I never get more than 2.96 Mbps of throughput. The stream averages 28 seconds behind OTA. The Starlink app shows that I have no obstructions and that the dish is perfectly aligned. This is the first time I have tested Starlink for streaming video from an OTT service. I am curious to hear what others have experienced with a Starlink Mini, so please share your experience in the comments on this LinkedIn post.

6pm: Kickoff is supposed to be at 6:30pm. Starlink is downloading a software update, and then I will also have details on how the stream works over Starlink.

For reference, here is a breakdown of streaming viewership for previous Super Bowl webcasts, but don’t go by the graphic alone. There are many differences across the years in how viewership was measured. See this post for a complete breakdown: Super Bowl Streaming Viewership Numbers From 2014-2025.

For the 2025 Super Bowl, FOX reported a rebuffer rate of 0.5%, a 28% share of viewership in 4K, and peak CDN capacity of 135 Tbps. You can see a detailed post-event breakdown of their workflow here: FOX Technical Presentation Details the Super Bowl LIX Streaming Video Stack

Here’s a breakdown of what I will be testing, along with more details on my setup:

• ISPs: Starlink, Verizon (500 Mbps), Optimum (300Mbps)
• OTA: Channel Master FLATenna and Mohu Leaf 50 TV antennas
• Platforms: Peacock, Sling TV, YouTube TV, NFL+, Hulu + Live TV, DirecTV, DAZN (Google AI says Fubo will have the game, but they won’t due to the carriage dispute. Another AI fail.)
• Devices: Fire TV Stick/Cube (AFTMA08C15/AFTKM/S3L46N/K3R6AT/K2R2TE/GA5Z9L/A78V3N), Roku (3821X2, 3940X2, 4800, 3820, 3820CA2) Apple TV (A2843/A2169/A1842), DIRECTV Gemini (P21KW-500), iPads (6x different models), MacBooks (4x, all 2022 and newer), iPhone (14/15 Pro/16 Pro Max)
• TVs: LG (55C9AUA/65BXPUA/65NANO80T6A), Samsung (UN40F5500AF/QN65S90CAFXZA/QN1EF), Vizio (V4K65M-0804/V4K55M-0801), TCL Roku TV (65S451)
• All devices with ethernet or a supported ethernet adapter are being used, all other devices are on wifi
• Every device is running the lastest app and OS version available

Note: For those who have asked, I am not getting paid by anyone to cover the Super Bowl stream. I have done this for each Super Bowl since 2015.

Privately held CDN and infrastructure provider Gcore, headquartered in Luxembourg, is allowing me to disclose some of its financial figures, which show significant revenue growth over the past two years. The company ended 2025 with $140 million in revenue, of which CDN-specific revenue was $27 million.

From November 2024 to November 2025, CDN revenue grew month over month by close to 55%. The company said that over the past two years, it had reduced CDN pricing in some regions, but strong demand and new large customers drove rapid traffic growth, making streaming one of Gcore’s fastest-growing CDN segments. Gcore has 550+ employees, raised a $70 million Series A in 2024, and says both the company as a whole and the CDN business are cash flow positive.

Gcore also said that, with several providers exiting the market, the redistribution of a portion of customers’ traffic to new CDNs contributed to meaningful growth. The company ended 2023 with just under $76 million in revenue, up nearly 60% from two years earlier. The company ended the year with 200 Tbps of network capacity across 210 CDN PoPs globally. Gcore says it has $12 million in customer commitments to expand its network next year and expects to add 65 Tbps in the first half of 2026.

The company also provided a detailed regional breakdown of Gcore’s global traffic, with the largest being North America at 29.4%, Europe at 27%.3%, Asia at 13.5% and South America at 13.3%. The company says its proprietary caching engine enables ~0.9 Gbps per server core, and Gcore supports HLS/DASH, LL-HLS/LL-DASH, WebRTC, QUIC/gQUIC transport and GPU-accelerated encoding. The company was founded in 2014 and has been offering CDN services and compute at the edge since then, with DAZN and Microsoft among its clients. If you are attending the NAB Show, you can see them at the NAB Show Streaming Summit.

In one of the most detailed blog posts yet [3,200 words], Netflix describes the custom Origin Server it built for live. The sentence I like most states that Netflix took a platform originally built for VOD and simply “extended nginx’s proxy-caching functionality to address live-specific needs.” This goes against those who claim that Netflix can’t deliver live streaming at scale because it “wasn’t built for live,” and of course, contradicts all the public viewership data, with Netflix having successfully streamed live events with an AMA number in the tens of millions. There is so much great info in the post, so here’s just a few things I wanted to highlight:

➡️ Leveraging Netflix’s microservice platform priority rate limiting feature, the origin prioritizes live edge traffic over DVR traffic during periods of high load on the storage platform. To mitigate traffic surges, TTL cache control is used alongside priority rate limiting. When low-priority traffic is impacted, the origin instructs Open Connect to slow down and cache identical requests for 5 seconds by setting max-age = 5s, and returns an HTTP 503 error code. This strategy effectively dampens traffic surges by preventing repeated requests to the origin within that 5-second window.

➡️ Netflix’s combination of cache and highly available storage has met the demanding needs of its Live Origin for over a year, and the solution they built was significantly more expensive, but minimizing cost was not a key objective, and low latency with high availability was.

➡️ Netflix uses failover orchestrated at the server-side to reduce client complexity, with resilience achieved through redundant regional live streaming pipelines and implements epoch locking at the cloud encoder, which enables the origin to select a segment from either encoding pipeline.

➡️ Netflix’s redundant cloud streaming pipelines operate independently, encompassing distinct cloud regions, contribution feeds, encoder, and packager deployments to substantially mitigate the probability of simultaneous defective segments across the dual pipelines.

➡️ Millisecond grain caching was added to nginx to enhance the standard HTTP Cache Control, which only works at second granularity, a long time when segments are generated every 2 seconds.

➡️ Netflix’s enhanced cache invalidation and origin masking enable live streaming operations to hide known problematic segments from streaming clients once the bad segments are detected, protecting millions of streaming clients during the DVR playback window.

You can read the entire Netflix blog post here.

Stats Perform acquired the assets of the ultra-low-latency tech company Phenix Real Time Solutions for approximately $7 million, including 21 patents. Stats Perform also rehired most of the former employees, with approximately nine coming over. In June of 2025, VC firm KB Partners put the assets of Phenix Real Time Solutions up for sale after the company continued to lose money, to the tune of almost $10 million last year, on sales of about $4 million.

No vendor can survive by selling a low/ultra-low latency solution as a stand-alone offering, as it must be sold as part of a larger video platform. This is exactly why the asset acquisiton makes sense for Stats Perform, which offers data collection and predictive analysis services tied to fantasy sports and sports betting. Ultra-low-latency tech can also help prevent piracy, a topic Stats Perform is discussing with leagues, OTT platforms and rights holders.

In the betting world, ultra-low-latency tech is needed to improve fan engagement, and Stats Perform has customers including the Premier League, WTA, FIBA, La Liga, and Serie A. Stats Perform is also FIFA’s first-ever official global distributor for betting data and live streaming rights, so it will be interesting to watch if FIFA wants to leverage any of the tech within their services. I can also think of how the ULL tech might be used to keep video in sync within a multiview feed.

Stats Perform tells me that while Phenix’s WebRTC-based tech works really well, Phenix never built the platform to scale or be cost-effective. Phenix never shared many details about its costs, but it once admitted that its platform was not designed to support more than 500,000 concurrent streams and that the overhead was expensive, even when it wasn’t being used.

Stats Perform has relaunched the Phenix tech within its platform, having already cut operating costs in half and continues to scale the tech, further reducing costs. This is exactly how ULL technology should be deployed, as a feature of a larger platform, not as a stand-alone service. Stats Perform will be well-positioned to monetize the tech across its entire platform for teams, leagues, broadcasters, betting companies, and social media. Stats Perform dominates its industry with an annual run rate of more than $550 million, nearly 2,800 employees and owns more than 560 patents.