Downstream and upstream traffic continued to climb last year as apps like streaming dominated, but usage patterns began to revert back to pre-pandemic patterns, Comcast revealed in its "2021 Network Report."
Comcast said peak downstream traffic in 2021 rose 11% over 2020 levels, while peak upstream traffic rose just 5%. By comparison, 2020 network traffic levels spiked considerably – peak downstream traffic rose 38% while upstream traffic surged 56% – as millions of people worked and schooled from home.
Asymmetry still rules
Comcast's latest report also showed that traffic patterns remained highly asymmetrical, as peak downstream traffic grew about two-times faster than upstream traffic, mirroring pre-pandemic levels. That trend toward increased asymmetry continued throughout 2021, as total downstream traffic volumes were 12.4x higher than upstream traffic for the first six months of the year, then climbed to 14.5x higher for the last six months of the year.
Usage patterns have also begun to revert to pre-pandemic times as students started returning to schools and parts of the workforce made their way back to offices. Comcast found that daily peak times occurred at 10 a.m. in January 2021, moved to 3 p.m. in June 2021, and then shifted to 10 p.m. by December 2021.
Streaming dominates again in 2021
From a content standpoint, video streaming, at 71%, dominated peak network traffic on Comcast's network in 2021, compared to 11% for gaming apps, 9% for web browsing and 2% for software updates.
Comcast said it has been able to keep its network ahead of demand since the pandemic caused usage spikes. "We certainly haven't had time to sit still during the past two years, but thanks to billions of investment, continuous innovation, and most importantly the incredible team we have working on the network at every level, we have stayed well ahead of demand, which is really borne out by our performance delivering above-advertised speeds to customers throughout the pandemic," Elad Nafshi, EVP and chief network officer, said via email in response to questions.
Even as the traffic patterns remained relatively asymmetrical in 2021, there's already been a significant run-up into early 2022 of the deployment and expansion of multi-gigabit, symmetrical broadband services from telco competitors such as AT&T, Frontier Communications, Verizon and Ziply Fiber.
Comcast has an answer with Gigabit Pro, a targeted, residential fiber-to-the-premises (FTTP) service that was recently upgraded to deliver symmetrical speeds of 3 Gbit/s. The cable operator also offers up to 1.2Gbit/s downstream and 35Mbit/s upstream on its DOCSIS 3.1 network.
"We're always building our network in anticipation of whatever our customers may need in the future, so while traffic today remains heavily asymmetrical – with downstream accounting for 14.5x as much volume as upstream in the last six months of 2021 – we continue to be really excited about the multi-gig symmetrical capacity we are developing for our HFC plant, because it offers a unique path to provide those experiences to customers at scale," Nafshi explained.
Comcast and other cable operators are now starting to focus on DOCSIS 4.0, a new platform for hybrid fiber/coax (HFC) networks that can deliver up to 10Gbit/s downstream and 6Gbit/s upstream. Recent Comcast tests have generated symmetrical speeds of 4 Gbit/s. Comcast has not announced when it expects DOCSIS 4.0-based services to be ready for prime time.
— Jeff Baumgartner, Senior Editor, Light Reading
A version of this story first appeared on Light Reading.