Cover of the 2021 Network Report.
Network and Engineering 

Comcast 2021 Network Report: Traffic Increased Over Historic 2020 Levels, Even as Usage Shifted Toward Pre-Pandemic Patterns

Key Takeaways

In 2021 alone, Comcast invested more than $4.2 billion to strengthen, expand and evolve the network – more than any previous year.
Traffic patterns remained highly asymmetrical, as peak downstream traffic grew 2x faster than upstream traffic, more closely mirroring pre-pandemic trends.
Similar to last year, entertainment activities dominated peak network traffic, with video streaming accounting for 71 percent of downstream traffic.

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After hitting historic peaks in 2020, traffic on the Comcast network grew again in 2021, according to the Comcast 2021 Network Report, released today.

Backed by billions in strategic investment and groundbreaking advances in network technology, the Comcast network continued to thrive and delivered above-advertised speeds to customers throughout this unprecedented era.

 

The data show a gradual shift throughout the year toward pre-pandemic traffic patterns. This included peak downstream traffic once again increasing faster than upstream traffic, and peak usage times shifting from earlier in the day to later in the evening. Peak downstream (download) traffic increased 11 percent over 2020 levels, while peak upstream (upload) traffic increased 5 percent. While less dramatic than the historic spikes of 2020 – when peak downstream traffic rose 38 percent and upstream traffic grew 56 percent – it is noteworthy that demand continued to increase even from historic 2020 highs.

+11%

Increase in peak downstream download traffic over 2020 levels

“Over the past two years, our network has been a powerful and reliable pillar for our customers as they’ve navigated dramatic changes in how we live, learn, play and work,” said Charlie Herrin, President of Technology, Product, Experience at Comcast Cable. “The outstanding performance of the network throughout this time is a testament to our commitment to strategic investment, unceasing innovation, and the incredible talent and dedication of our technology teams across the country.”

2021 at a glance

Traffic was Asymmetrical

  • Traffic patterns remained highly asymmetrical, as peak downstream traffic grew 2x faster than upstream traffic, more closely mirroring pre-pandemic trends
  • Network asymmetry increased throughout the year, with total downstream traffic volumes 12.4x higher than upstream for the first 6 months of the year, and 14.5x higher for the last six months
  • Daily peak times shifted toward pre-pandemic norms throughout the year – peak upstream traffic times were 10am in January, 3pm in June, and 10pm in December

    2021 Network Traffic

    • Streaming, web browsing, and gaming all saw the largest increases in network consumption with a 10-20 percent increase for all three categories
    • Similar to last year, entertainment activities dominated peak network traffic, with video streaming accounting for 71 percent of downstream traffic (same as 2020)
    • Other activities that contributed to peak downstream traffic include both online gaming and web browsing which both increased their share of network usage by 1 percentage point over 2020 levels
    • Videoconferencing as a share of peak network traffic decreased slightly in 2021, remaining less than 5 percent

    Continuous network innovation has been essential not just to managing the pandemic traffic surge, but also in future-proofing the network as demand continues to grow. In addition to smart software and virtualization technologies that increase performance and reliability, Comcast took major steps in 2021 toward the next phase of network evolution: 10G.

    “Network investment is important, but the network architects and software engineers across Comcast are also innovating at the speed of software,” said Elad Nafshi, EVP & Chief Network Officer at Comcast Cable. “Our colleagues leading these innovations are creating the future for our customers.”