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types are marked with the name of the
content. A user interested in specific
content creates an interest packet and
sends it into the network. The NDN
routing protocol is based on a name-prefix strategy, which, in some ways,
is similar to prefix aggregation in IP
routing. An NDN router, however, differs from IP routers in two important
ways: it maintains a temporary cache
of data that it has seen so far, so that
any new interests from downstream
nodes can be responded to directly
without going to an upstream router;
and only one request is sent to the upstream router for multiple interests to
the same name by a number of downstream nodes. Multiple paths for the
same content are also supported.
The security in NDN is also data-centric. The producer of the data cryptographically signs each data packet,
and a consumer can reason about data
integrity and provenance from such
signatures. In addition, encryption of
data packets can be used to control access to information.
Using human-readable names allows for the creation of predictable
names for content, which is useful for
a certain class of applications. The
paper also describes how applications would look with NDN by using
a number of examples such as video
streaming, real-time conferencing,
building automation systems, and vehicular networking.
NDN is not the first ICN, and it isn’t
the last. Earlier ICNs were based on flat
cryptographic identifiers for addresses, compared to NDN’s hierarchical
human-readable names. A more detailed overview of ICNs, their challenges, commonalities, and differences
can be found in a 2011 survey paper by
Ghodsi et al. ( https://dl.acm.org/cita-
tion.cfm?id=2070563).
To provide a little historical context, NDN was one of several future
Internet architectures (FIAs) funded
by the National Science Foundation.
It is instructive to look at a few other
projects, such as XIA ( https://dl.acm.
org/ citation.cfm?id=2070564) and
MobilityFirst ( https://dl.acm.org/cita-
tion.cfm?id=2089017), which share the
goals of cleaner architectures for the
future Internet.
The key lesson for practitioners is
that choosing the right level of abstrac-
cloud, and everywhere in between
form a continuum. Thus, for power
users such as factory floors, city infra-
structures, corporations, small busi-
nesses, and even some individuals,
edge computing means making ap-
propriate use of on-premises resourc-
es together with their current reliance
on the cloud. In addition to existing
cloud providers, a large number of
smaller but more optimally located
service providers, that handle the
overflow demand from power users as
well as support novice users, are likely
to flourish.
Creating edge computing infrastructures and applications encompasses quite a breadth of systems
research. Let’s take a look at the academic view of edge computing and a
sample of existing research that will be
relevant in the coming years.
A Vision For Edge Computing:
Opportunities And Challenges
Let’s start with an excellent paper that
introduced the term fog computing and
highlights why practitioners should
care about it:
Fog Computing and Its Role in
the Internet of Things
F. Bonomi, R. Milito, J. Zhu, and S. Addepalli
In Proceedings of the First Edition of the
ACM Workshop on Mobile Cloud Computing,
(2012) 3–16; https://dl.acm.org/citation.
cfm?id=2342513
Although short, this paper provides a
clear characterization of fog computing and a concise list of the opportunities it provides. It then goes deeper
into the discussion of richer applications and services enabled by fog computing, such as connected vehicles,
smart grid, and wireless sensor/actua-tor networks. The key takeaway is that
the stricter performance/QoS requirements of these rich applications and
services need: better architectures for
compute, storage, and networking;
and appropriate orchestration and
management of resources.
While this paper is specifically about
the Internet of Things and fog com-
puting, the same ideas apply to edge
computing in the broader sense. Un-
surprisingly, the opportunities of edge
computing also come with a number of
challenges. An in-depth case study of
some of these challenges and possible
workarounds is illustrated in the Farm-
Beats project that was discussed in the
RfP “Toward a Network of Connected
Things” featured in the July 2018 issue
of Communications, p. 52–54.
A World Full of Information:
Why Naming Matters
One of the hurdles in using resources
at the edge is the complexity they bring
with them. What can be done to ease
the management complexity? Are existing architectures an attempt to find
workarounds for some more fundamental problems?
Information-centric networks
(ICNs) postulate that most applications care only about information, but
the current Internet architecture involves shoehorning these applications
into a message-oriented, host-to-host
network. While a number of ICNs have
been proposed in the past, a recent notable paper addresses named data networking (NDN).
Named Data Networking
L. Zhang et al.
ACM SIGCOMM Computer Communication Rev.
44,
3 (2014), 66–63; https://dl.acm.org/citation.
cfm?id=2656887
NDN, like many other ICNs, considers named information as a first-class
citizen. Information is named with
human-readable identifiers in a hierarchical manner, and the information
can be directly accessed by its name
instead of through a host-based URL
scheme.
As for the architecture of the routing network itself, NDN has two types
of packets: interest and data. Both