Page 84 - 5G Basics - Core Network Aspects

1 Core network aspects

framework of software-defined networking (SDN), which is characterized by a well-defined separation
between user and control planes.

8 Migration
Implementation of each service scenario is subject to the migration from current networking to DAN.
Nevertheless, the migration can be gradual. There are two deployment options.

One deployment option is based on network virtualization technology, which includes an overlay model and
slice model. In the overlay model, DAN elements are selectively placed inside the current network. This model
is cost-effective due to the use of IP networks for networking remote DAN elements. As the number of DAN
elements increases, DAN can provide more efficiency and scalability. DAN elements can be used as gateway
nodes next to the conventional network elements and serve the desired functions for each service scenario
like caching, aggregation and protocol translation between DAN and the existing network, etc. In the slice
model, a network slice is created on the current network and DAN is deployed on the slice. This model has
the merit of easy extension by horizontal or vertical cooperation with other slices.

The other option is based on a clean-slate mechanism, where the IP layer of the current network is totally
replaced by the name or ID layer of DAN for name-based routing. This option can utilize DAN capabilities
most effectively. However, it is realistic to use network technology properly according to network usage and
service requirements, rather than replacing hastily all networks by DAN. Actually, this replacement could be
done gradually on the basis of management domain. For example, a newly introduced network may be
constructed on pure DAN technology. DAN elements on the edge should provide gateway functions as well,
so that DAN and existing networks can communicate with each other.

9 Environmental considerations
Environmental considerations in this Supplement are mainly subject to those provided by DAN: its extra
energy consumption due to the requirement for additional resources (e.g., cache or storage) for its operation.
Thus, the environment considerations specified in [ITU-T Y.3033] would be sufficient for this Supplement.

10 Security considerations

The security consideration in this Supplement are mainly subject to the security mechanism provided by DAN,
which secures each data object based on the signature of its publisher rather than securing the connection
between two end points. This security mechanism assumes that users can access the public key
infrastructure. However, this assumption may not be valid in some DAN service scenarios, such as networking
in a disaster area where users are isolated from the public key infrastructure. Therefore, an additional
security mechanism may be required for a particular DAN service scenario.

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