A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Brand New Design <s> In the absence of end-to-end quality of service (QoS), overlay routing has been used as an alternative to the default best effort Internet routing. Using end-to-end network measurement, the problematic parts of the path can be bypassed, resulting in improving the resiliency and robustness to failures. Studies have shown that overlay paths can give better latency, loss rate, and TCP throughput. Overlay routing also offers flexibility as different routes can be used based on application needs. There have been very few proposals of using bandwidth as the main metric of interest, which is of great concern in media applications. We introduce our scheme BARON (Bandwidth-Aware Routing in Overlay Networks) that utilizes capacity between the end hosts to identify viable overlay paths and measures available bandwidth to select the best route. We propose our path selection approaches, and using the measurements between 174 PlanetLab nodes and over 13,189 paths, we evaluate the usefulness of overlay routes in terms of bandwidth gain. Our results show that among 658,526 overlay paths, 25% have larger bandwidth than their native IP routes, and over 86% of (source, destination) pairs have at least one overlay route with larger bandwidth than the default IP routes. We also present the effectiveness of BARON in preserving the bandwidth requirement over time for a few selected Internet paths. <s> BIB001 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Brand New Design <s> The concurrent use of multiple paths through a communications network has the potential to provide many benefits, including better utilisation of the network and increased robustness. A key part of a multipath network architecture is the ability for routing protocols to install multiple routes over multiple paths in the routing table. In this paper we propose changes to local BGP processing that allow a BGP router to use multiple paths concurrently without compromising loop-freeness. <s> BIB002 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Brand New Design <s> Software Defined Networking (SDN) separates the tightly coupled network control and data forwarding functions. During the past years, it has been applied in all kinds of intra-domain networks, such as enterprise networks, data centers and content provider networks. However, it is a big challenge to extend SDN to inter-domain networks. In this paper, we extend the advantage of SDN to an inter-domain network federation to improve the Internet routing flexibility. To achieve this goal, we propose a Multi-dimension Link Vector network view exchange mechanism (MLV) to exchange the fine-grained inter-domain routing information and enable programmable inter-domain routing. MLV can support flexible inter-domain routing control by exchanging multiple fields of the IP header. Based on MLV, innovations in inter-domain routing can be deployed as applications over SDN controllers. In order to validate the MLV design, we analyzed its performance with BGP-derived Internet AS topology. Finally, we implemented a prototype of MLV and tested it on an internationally collaborative inter-domain SDN testbed. <s> BIB003 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Brand New Design <s> The Internet reserves numerous potential path diversity among densely connected autonomous systems (ASes). However, the Internet routing is controlled by Border Gateway Protocol (BGP), which has limitations in the path diversity expression and cooperation between ASes. The emergence of software defined networking (SDN) scheme provides flexible control over networks. In this paper, we leverage the programmability of SDN, and propose a new routing control plane, named RCS. It can support flexible inter-domain forwarding control, and enable network functions chaining along inter-domain paths. In RCS, network functions are abstracted and disseminated between SDN ASes. Customer networks can set up their desired routing paths for particular applications, such as multipath routing. RCS can be deployed incrementally to apply SDN to current inter-domain settings. In our primary analysis based on BGP data, the provision of customizable forwarding control at only a few ASes can lead to a large of potential path diversity. <s> BIB004 </s> A Survey on Efforts to Evolve the Control Plane of Inter-Domain Routing <s> Brand New Design <s> Software-defined networking (SDN) scheme decouples network control plane and data plane, which can improve the flexibility of traffic management in networks. OpenFlow is a promising implementation instance of SDN scheme and has been applied to enterprise networks and data center networks in practice. However, it has less effort to spread SDN control scheme over the Internet to conquer the ossification of inter-domain routing. In this paper, we further innovate to the SDN inter-domain routing inspired by the OpenFlow protocol. We apply SDN flow-based routing control to inter-domain routing and propose a fine-granularity inter-domain routing mechanism, named SDI (Software Defined Inter-domain routing). It enables inter-domain routing to support the flexible routing policy by matching multiple fields of IP packet header. We also propose a method to reduce redundant flow entries for inter-domain settings. And, we implement a prototype and deploy it on a multi-domain testbed. <s> BIB005
Clean-slate redesigns seem to be a very attractive approach to make a new control plane for inter-domain routing without the cumbersome backward compatibilities requirements. For traditional networks, a new protocol for inter-domain routing has the potential to overcome the limitations and drawbacks of the BGP. Table 3 compiles works with a brand new design for inter-domain routing using the criteria presented in Section 5.1. Feedback-Based Routing (FBR)  was inspired by standard engineering practice of design dynamic systems with feedback control theory. Thus, instead of using just connectivity information for routing like the BGP, FBR creates the network state based on connectivity and structural information (such as quality and state of inter-domain links) received from routers that composed the final solution. FBR developed and used its own protocol for inter-domain routing, the Wide-area Relay Addressing Protocol (WRAP). With WRAP, FBR applies a sourcing routing scheme where the core routers of the Internet should be in charge of propagating structural information while the routing decisions occur at the routers at the edge of the network, in which they compute the network routing to achieve the end-to-end performance requirements. Bandwidth-Aware Routing in Overlay Networks (BARON) BIB001 was a proposal to overcome the limitations of the default best effort Internet routing. Hence, overlay routing was used to improve end-to-end performance parameters, especially the bandwidth requirement. Furthermore, to create a feasible and scalable solution, BARON explores the Distributed Information Nodes (DINs) database that was used to distribute the node information across the network. The major drawback of overlay solutions for evolving inter-domain routing is that they normally imply additional complexity regarding the overhead that the tunnels introduce in order to be properly managed. Fujinoki  proposed the Multi-Path BGP (MBGP) to improve the network bandwidth utilization and avoid dis-connectivity when an external link fails. MBGP was a new network protocol to explore the multipath with a solution based on BGP updates. Furthermore, to overcome a single route for a destination network, the Multipath BGP BIB002 proposed a change in the BGP's path selection and path dissemination rules to explore the utilization of multiple paths in concurrence without compromising loop-freeness. Although MBGP and Multipath BGP are solutions to increase the exploration of path diversity on the Internet, the proposals were only tested in simulations, and how the network traffic should be split across multiple paths was not appropriately discussed. Another Multipath Interdomain Routing (AMIR)  was a proposal for a new AS-level routing scheme to explore the use of concurrent multiple paths on the Internet. AMIR was designed to compute primary and alternative paths based on negotiating path provisioning among neighboring ASs. The AMIR scheme explores the best available paths for forwarding data in a source routing fashion. Thereby, a given domain can receive multiple paths from its inter-domain partners and choose the best one. Hence, AMIR had the potential to improve the experience of user applications from the network perspective and had the benefit of allowing a more intensified business relationship between ASs that deploy the solution. Regarding the architecture scheme, the work of Yang et al.  presents a new inter-domain routing architecture called NIRA ("New Internet Routing Architecture") that gives the end-host (users) and stub ASs the ability to choose the sequence of ISPs that their packets can take. On the current Internet, the routes are chosen by ASs running the BGP without considered the network source to make routing decisions. The main idea of NIRA was to give the users the ability to choose routes for the Internet from a source routing approach. Thus, the users could select routes that lead to improvement of their network performance, reliability or user satisfaction. Although the NIRA's objective was to transform the Internet architecture, it requires the adoption of a new network protocol called the Topology Information Propagation Protocol (TIPP) to work properly. Applying the SDN concepts, the Multi-dimension Link Vector (MLV) BIB003 presented a new mechanism to exchange the network view. MLV uses the OpenFlow protocol  in its data plane elements and enables flexible inter-domain routing in an SDN network federation. MLV is a solution based on a link vector algorithm for representing the inter-domain state of the network. With the exchanging of the link vector data structure and the fine-grained rules provided by OpenFlow, the network operator could make decisions regarding paths combining that information. Despite the fact that MLV was a proposal to evolve inter-domain routing among SDN networks, the link vector data structure imposes scalability concerns. The Route Chaining System (RCS) BIB004 follows the concept of SDN networks to allow ASs to select routes that do not follow the standard BGP algorithm and explore the possibility of diversity paths of the Internet. RCS focuses on control traffic on transit ASs from the AS source to destinations and also requires an inter-domain communication layer between ASs to enable the multiple and distributed control planes to be connected to compose the solution. Software-Defined Inter-domain (SDI) routing BIB005 advances into the inter-domain support of flexible routing policies to forwarding packets, where multiple fields of the IP packet header could be used for matching (flow-level), instead of just using the BGP's destination-based forwarding paradigm. SDI also provides a mechanism to treat a large number of flow table entries required to represent the forwarding fine-grained flows. For the control plane placement, the SDI solution keeps each domain with its own control plane, which computes paths individually. To explore the path diversity between SDI domains, flow schemes are exchanged. Summary: Clean-slate proposals are suitable for a very specific application, when used, and cannot be broadly adopted because they are incompatible with the current control plane of the Internet. In addition to traditional solutions, a new protocol proposal must be executed inside network devices or all network devices that utilize such solutions need to be modified, and such a situation may require CAPEX (CAPital EXpenditure) and OPEX (OPerational EXpenditure) to be operational. For example, the network staff would need to be trained for new proposals or protocols, as well as acquire new network devices that support those clean-slate solutions. For the inter-domain routing system with the SDN solutions, those whose approaches are not compatible with the BGP have little practical appeal for wide adoption (such as MLV BIB003 ), and solutions that propagate a detailed representation of the network state suffer from scalability limitations.