Communications of the ACM

DNS entirely. This is a fantastic wholesale change, but the tradeoff is that it will require users to dramatically modify how they access content.

Since a P2P design is dependent
on the total network size, this model
has difficulty growing until it reaches
critical mass. At Edgemesh, we want-
ed to focus on enhancing existing
Web-content delivery transparently
(for example, in the browser) without
requiring any changes to the user ex-
perience. This means ensuring that
the technology abides by the following
three restrictions:

˲ For users, the solution should be transparent.

˲ For developers, the solution should require zero infrastructure changes.

˲ For operations, the solution should be self-managing.

The next question is where exactly to focus.

Fully enabling peer-enhanced delivery of all content is difficult and dangerous, especially allowing for peer-delivered JavaScript to be executed. Is there an 80% solution? Trends posted by HTTP Archive reveal that static components (images/video/ fonts/CSS) make up roughly 81% of the total page weight. 9

Given these details, let’s narrow
the focus to enabling/enhancing edge
delivery of these more traditional
CDN assets and the associated chal-
lenges of moving and storing data.
Moving data: Building a new net-
work (overlay). To support P2P distribu-
tion, an overlay network needs to be de-
veloped to allow the P2P connections
to operate within the larger existing
Internet infrastructure. Luckily, such
a stack is available: WebRTC (Real-
Time Communications19). Started in
earnest in 2011 by Google, WebRTC is
an in-browser networking stack that
enables peer-to-peer communication.
WebRTC is primarily employed by
voice and video applications (Google
Hangouts/Dua/Allo, Slack, Snapchat,
Amazon Chime, WhatsApp, Facebook
Messenger) to facilitate peer-to-peer
video- and audioconferencing.

WebRTC is a big deal; in June 2016 Google provided several key milestones7 from stats it collected, with some additional updates six months later: 25

˲ Two billion Chrome browsers with WebRTC.

˲ One billion WebRTC audio/video minutes per week on Chrome.

˲ One petabyte of DataChannel traffic per week on Chrome (0.1% of all Web traffic).

˲ 1,200 WebRTC-based companies and projects (it was 950 in June).

˲ Five billion mobile app downloads that include WebRTC.

WebRTC support exists in the major browsers—Chrome, Firefox, Edge, and now Safari, 2 Comparing WebR TC’s five-year adoption against other VoIP-style protocols shows the scale. 8

Figure 6. Performance increased by routing preference.

100

80

60

40

20

0
Cum
u
lati
v
ePe
rce
nt
o
fS
amp
le
s
Latency Buckets (Ms)
cross_asintra_as
180-199,

0.490317052

380-399,
0.464235869

20–39 80–99140–159200–219260–279320–339380–399440–459500–519560–579620–639680–689740–759800–819880–899940–959 Figure 5. Flow diagram for WebRTC Enhanced asset delivery.