the concept of
an icn does not
to take on host-
instead, it detaches
the application from
homed ICN node could seamlessly exploit these different interfaces without
needing to understand which interface
has actually been used.
Network address consistency.
Currently, many mobility mechanisms attempt to maintain consistency in the
node’s network address. This is vital
for many applications that may utilize
a node’s IP address for long-term usage. A typical example is BitTorrent,
which will see a node’s IP address being registered with a tracker for future
discovery. Mobile IP, 22 for instance, introduces the concept of a Home Agent
to allow hosts to change their physical
address, while still maintaining a constant public address. This, however,
creates undesirable overheads due to
the need to tunnel data through this
Home Agent. Unfortunately, the alternative requires greater intelligence in
applications to make them aware of
mobility, thereby allowing them to update their location information.
In contrast, the concept of an ICN
does not force applications to take on
host-centric information. Instead, it
detaches the application from such
concerns. This allows the application
to abstractly publish or consume content, without the need to store (or even
know) its own network-layer address.
In essence, it promotes content, which
is already an explicit application-layer
element, to an explicit network-layer
entity as well, thereby requiring the application to only maintain knowledge
that does not deviate from its own traditional knowledge base.
Removal of connection-oriented
sessions. A key problem with mobility in
host-centric networks is their frequent
dependency on connection-oriented
protocols (for example, TCP). Thus,
mobility can often require the reestab-
lishment of these connection-oriented
sessions so that both parties are aware
of the up-to-date network addresses,
as well as any pertinent parameters.
Generally, TCP sessions are used in
host-centric networks to establish re-
liability parameters (for example, se-
quence numbers) and configure flow/
congestion control (for example, win-
dow size). This is necessary because
the network stack does not have an
explicit understanding of the data it is
sending/receiving, therefore requiring
bilateral cooperation to ensure a re-
addresses). In contrast, ICNs route (or
bind) between points of consumption
and optimal content sources.
˲ Security: Host-centric networks attempt to secure communication channels between hosts. In contrast, ICNs
attempt to secure the integrity of individual content objects, regardless of
their delivery mechanism.
˲ API: Host-centric networks expose
APIs that allow data to be sent to a given location. In contrast, ICNs expose
APIs that allow content to be published
In the remainder of this article, we
explore the benefits of the differences
mentioned here, specifically from the
viewpoint of improving node mobility.
What are the Benefits
of icn for mobility?
The proposed improvement in mobility support is achieved by refocusing
network routing on content objects,
rather than hosts. Consequently, in an
ICN, changes in a node’s physical location do not necessarily need changes
in its related network information (for
example, routing state). This high-level
concept therefore opens up many potential benefits. Here, we look at some
of the possible advantages that could
be gained if the theoretical principles
of ICN were realized.
Host multihoming. A long-standing
challenge in host-centric networks is
allowing mobile hosts to exploit multiple network interfaces (for example,
Bluetooth, UMTS, Wi-Fi, among others). This is because typically most protocols rely on establishing individual
connections using each host’s address.
However, because an address is bound
to a specific network interface, it is difficult to easily switch between them.
For example, a HTTP GET request is always received over a single TCP connection from a single source address. Consequently, during mobile hand-offs, it
is difficult to exploit multiple potential
network interfaces that might be available when using HTTP.
In contrast, the concept of an ICN
detaches itself from host-to-host connections. Instead, communications
within an ICN are typically based
around a request/reply model. As such,
requests can easily be multiplexed
over multiple interfaces. This means
that applications running on a multi-