A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Backward Compatibility <s> This document, together with its companion document, "Application of the Border Gateway Protocol in the Internet", define an inter- autonomous system routing protocol for the Internet. <s> BIB001 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Backward Compatibility <s> This article surveys several research challenges in interdomain routing. We introduce and describe these challenges in a comprehensible manner, along with a review of the most compelling contributions and ongoing research efforts addressing each of the exposed issues. During this analysis we identify the relation between these research challenges and now they influence each other. We also present our perspectives on why these issues remain largely unsolved, and point out why some of the proposals made so far have not yet been adopted. We hope this can provide some insight on future directions in this complex research area. <s> BIB002 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Backward Compatibility <s> In this paper, we review why BGP is a poor candidate to facilitate the next generation of Software Defined Networks (SDN) and propose the Interdomain Management Layer (IML) architecture, a framework for facilitating interdomain resource sharing between these networks. IML uses a concept we call horizontal slicing, that allows SDN networks to become autonomous peers with other ASes, while maintaining centralized, operator-facing policy control and end-to- end flow control across interdomain boundaries. <s> BIB003 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Backward Compatibility <s> The Border Gateway Protocol (BGP) was designed almost three decades ago and has many limitations relating to its fully distributed nature, policy enforcement capabilities, scalability, security and complexity. For example, the control plane can take several minutes to converge after a routing change; this may be unacceptable for real-time network services. Despite many research proposals for incremental improvements and clean-slate redesigns of how inter-domain routing should work, BGP is likely one of the most ossified protocols of the Internet architecture and it has not retrofitted the proposed ideas. In this work, we propose a radical, incrementally deployable Internet routing paradigm in which the control plane of multiple networks is logically centralized. This follows the Software Defined Networking (SDN) paradigm, although at the inter-domain level involving multiple Autonomous Systems (AS). Multi-domain SDN centralization can be realized by outsourcing routing functions to an external contractor, which provides inter-domain routing services facilitated through a multi-AS network controller. The proposed model promises to become a vehicle for evolving BGP and uses the bird's eye view over several networks to benefit aspects of inter-domain routing, such as convergence properties, policy conflict resolution, inter-domain troubleshooting, and collaborative security. In addition to the proposed paradigm, we introduce a publicly available emulation platform built on top of Mininet and the Quagga routing software, for experimenting on hybrid BGP-SDN AS-level networks. As a proof of concept, we focus specifically on exploiting multi-domain centralization to improve BGP's slow convergence. We build and make publicly available a first multi-AS controller tailored to this use case and demonstrate experimentally that SDN centralization helps to linearly reduce BGP convergence times and churn rates with expanding SDN deployments. <s> BIB004 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Backward Compatibility <s> The Border Gateway Protocol (BGP) is the current standard protocol for the inter-domain routing system. Although BGP makes easy to manipulate the output traffic by an Autonomous System (AS), it lacks other desired features such as convenient management of incoming traffic to an AS. Thus, we propose a framework to evolve the control plane routing system that is compatible with BGP (smooth transition), uses SDN technologies and can be used to management the incoming traffic of multihomed ASes. Based on our framework, a load balancing application was developed and applied to a scenario to depict the proof of concept of our framework. The results were compared and discussed with BGP AS-Path Prepending technique, shown an improvement of inbound traffic bandwidth utilization. <s> BIB005
A new feature for the BGP has to have a minimum integration within heterogeneous networks and operate through different administrative domains (e.g., the Internet). Those requirements frustrated new proposals to evolve the BGP and the ecosystem of inter-domain routing BIB005 . One of the main reasons for this is new proposals that have to be maintained with the infrastructure already built, and ASs will not rely on immature technologies that do not prove to be profitable or are not operable with other ASs on which they depend BIB003 . Thus, the difficult-to-change architecture of the Internet creates a mandatory requirement for integration among different proposals and the BGP. The backward compatibility imposes a limitation to "clean-slate" proposals. Brand new and incompatible BGP proposals are considered unrealistic BIB004 . In fact, in the more than two decades since the first version of the BGP protocol BIB001 , much scientific and industrial effort have been made to overcome the BGP limitations and failed to make it a flexible protocol. The backward compatibility with the BGP for the new approaches in the inter-domain environment continues to be a mandatory requirement. However, a major criticism of the BGP is that it is not suitable for the next generation of inter-domain networks BIB003 . The main argument to sustain that claim is any new proposal for inter-domain routing has to be part of traditional networks to operate on the Internet and those proposals will be restricted by the limitations of the BGP. Moreover, the BGP is a widely-adopted protocol used in the infrastructure of the major part of the Internet. It is an inflexible protocol, and it is difficult to incorporate new changes into the network infrastructure. Therefore, the control plane of the inter-domain routing must be evolved instead of receiving a revolution. Evolving the Internet control plane is not an easy task because to be practical and useful, it is almost mandatory to have backward compatibility with the current technologies BIB002 .