Comcast made good today on its obligations to tell the FCC exactly how it's currently managing its network and how it plans to manage it in the future. In an August 20 that rapped Comcast for interfering with P2P applications, the Commission ordered the operator to offer up details about its current and future traffic management practices, among other things.
Comcast submitted three documents to the FCC, one of which (PDF) delves into technological detail on how Comcast interferes with P2P traffic today and one of which (PDF) spells out how its "protocol agnostic" system will work. Although network engineers will no doubt find both of these documents fascinating, the most striking difference between the two network management practices is that the first, the current system which affects only P2P traffic, focuses solely on upstream bandwidth management, while the new protocol-agnostic method focuses on both upstream and downstream management.
The implications of this shift in focus could be significant for consumers, although it's too soon to tell. As Comcast explains to the FCC, its current P2P-oriented management system targets upstream traffic-only, presumably because the "asymmetric" nature of cable's Internet architecture makes the upstream, which has less capacity, more vulnerable to congestion.
But the new protocol agnostic system, which is contingent on bandwidth used regardless of application, throws users into what Comcast is calling an "extended high consumption state" if they exceed 70% consumption thresholds on either the upstream or downstream, i.e., if they use more than 70% of their allocated bandwidth in a fifteen-minute interval.
The User Consumption Threshold is measured as a user’s consumption of a particular percentage of his or her total provisioned upstream or downstream bandwidth (the maximum speed that a particular modem can achieve based on the tier (personal, commercial, etc.) the customer has purchased, e.g., if a user buys a service with speeds of 8 Mbps downstream and 1 Mbps upstream, then his or her provisioned downstream speed is 8 Mbps and provisioned upstream speed is 1 Mbps). The User Consumption Duration is measured in minutes.
If users are classified as "extended high consumers" by the system, their Internet traffic could be subject to delays, although Comcast says that packets will get delayed by about only 1/10th of a second. In market trials where Comcast has deployed the new system (Chambersburg, PA; Warrenton, VA; Lake City, FL; East Orange, FL; and Colorado Springs, CO), no one has complained about the traffic delays, the company contends.
Moreover, Comcast says that the consumption threshold is set high enough to cover much of what consumers do today on the Internet. Comcast’s standard-level service provisions downstream bandwidth at 6 Mbps, while streaming video from Hulu uses less than 2.5 Mbps, a Vonage or Skype VoIP call uses less than 131 Kbps, and streaming music uses less than 128 Kbps, the company says.
Still, if two users in a household are simultaneously watching Hulu on two different computers, then they'd be pushing up against the threshold and potentially subject to delays. (Comcast stresses that the new system affects users only when traffic is truly congested. If the network isn't being taxed, then no one should experience delays.) And as consumers continue to ramp up their use of online video and other bandwidth-intensive applications, it's possible that an increasing number of Comcast users would become frequently classified as "extended high consumers" and experience delays.
Whether that happens or not, the new system is clearly aimed at dowstream bandwidth consumption in addition to upstream traffic congestion. It makes a lot of sense to factor downstream capacity into any network management system. Comcast even states that "consumers still download much more than they upload."
But until now, Comcast hasn't been "managing" traffic to limit any kind of downstream capacity focusing instead on P2P via the upstream. For better or worse, that's about to change.
Posted by Cynthia Brumfield at 9:10 PM | Print | Comments (0)
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