The main resiliency goals of a network provider are (1) producing as little failures as possible and (2) reducing the impact of each remaining failure, given that some failures are unavoidable.
Securing a software-defined network imposes additional challenges, but also additional flexibility over a traditional network. In a network without controller most routings will be either entered manually or a routing protocol like Open Shortest Path First (OSPF, \cite{Moy.1998}) or Intermediate System to Intermediate System (IS-IS) would be used. In case a routing protocol is used, the routers themselves handle the routing in accordance to the definition of specified routing protocol. In the subsection \ref{ospf} we explain one of the traditional routing protocols OSPF and its implications. We put this into contrast in subsection \ref{sdn_advantages} where we discuss benefits and drawbacks of a SDN. After we established a basic overview over the differences of architectures, we shift our focus on resilience on the control plane and data plane specifically in subsection \ref{resilience_data_plane} and subsection \ref{resilience_control_plane}. While fast recovery methods (FRMs) mostly work on the data plane they take a role somewhere in between the data and control plane and are often used in addition to methods on the data and control plane. This is why we devote the subsection \ref{FRM} to the explanation of multiple FRMs and their applications.
Securing a software-defined network imposes additional challenges, but also additional flexibility over a traditional network. In a network without controller most routings will be either entered manually or a routing protocol like Open Shortest Path First (OSPF) (\cite{Moy.041998}) or Intermediate System to Intermediate System (IS-IS) (\cite{Callon.121990}) would be used. In case a routing protocol is used, the routers themselves handle the routing in accordance to the definition of specified routing protocol. In the subsection \ref{ospf} we explain one of the traditional routing protocols OSPF and its implications. We put this into contrast in subsection \ref{sdn_advantages} where we discuss benefits and drawbacks of a SDN. After we established a basic overview over the differences of architectures, we shift our focus on resilience on the control plane and data plane specifically in subsection \ref{resilience_data_plane} and subsection \ref{resilience_control_plane}. While fast recovery methods (FRMs) mostly work on the data plane they take a role somewhere in between the data and control plane and are often used in addition to methods on the data and control plane. This is why we devote the subsection \ref{FRM} to the explanation of multiple FRMs and their applications.
\subsection{Traditional routing protocols by taking the example of OSPF}
In the following chapter we will implement an examplary network in Mininet, including routing between hosts and routers.
Additionally we will implement fast re-routing as well as ShortCut. In section \ref{sec:test_network} we explain the test framework that we built for performing tests. In section \ref{implementation_rrt} we then explain how we implemented FRR in the test framework.
In the following chapter we implement an examplary network in Mininet, including routing between hosts and routers.
We also implement fast re-routing as well as ShortCut. In section \ref{sec:test_network} we explain the test framework that we built for performing tests. In section \ref{implementation_rrt} we then explain how we implemented FRR in the test framework.
Lastly we talk about our implementation of ShortCut in \ref{implementation_shortcut}
In recent years, especially during the COVID-19 pandemic, network usage has risen exponentially. In Germany alone the per capita data usage on the terrestrial network has risen from \SI{98}{\giga\byte} per month in 2017 to \SI{175}{\giga\byte} in 2020 (\cite{BundesnetzagenturDeutschland.2021}).
Many workers stayed at home, worked from home or were otherwise limited in their movement which has contributed to this rise in data usage. But this development is not limited to the pandemic. Data usage has been constantly rising due to the popularity of streaming services, increased internet usage in daily life and the rising popularity of cloud based services.
A large part of the population suddenly had to spent additional time in their homes which has contributed to this rise in data usage. But this development is not limited to the pandemic. Data usage has been constantly rising due to the popularity of streaming services, increased internet usage in daily life and the rising popularity of cloud based services.
Because of the increased usage, failing networks cause an increasingly severe amount of social and economic costs. This is why the reliability of networks is as important as ever.
Frederik Maaßen
2 years ago