Amaru: Plug&Play Resilient In-Band Control for SDN

Abstract

Software-Defined Networking (SDN) is a pillar of next-generation networks. Implementing SDN requires the establishment of a decoupled control communication, which might be installed either as an out-of-band or in-band network. While the benefits of in-band control networks seem apparent, no standard protocol exists and most of setups are based on ad-hoc solutions. This article defines Amaru, a protocol that provides plug&play resilient in-band control for SDN with low-complexity and high scalability. Amaru follows an exploration mechanism to find all possible paths between the controller and any node of the network, which drastically reduces convergence time and exchanged messages, while increasing robustness. Routing is based on masked MAC addresses, which also simplifies routing tables, minimizing the number of entries to one per path, independently of the network size. We evaluated Amaru with three different implementations and diverse types of networks and failures, and obtained excellent results, providing almost on-the-fly rerouting and low recovery time. INDEX TERMS SDN, OpenFlow, in-band control, resilient networks, path exploration.

Reliability Aware Multiple Path Installation in Software-Defined Networking

“…Amaru [29] is a protocol that works for failure handling. It incarcerates the multi objectives (i.e., fast bootstrapping, topological scalability) in in-band SDN control.…”

Scalable and Reliable Data Center Networks by Combining Source Routing and Automatic Labelling

“…Furthermore, RSTP did not allow the synchronization of the HLMAC suffixes, which is explained in the following paragraphs as one of the enhancements provided by eTorii. Therefore, this labelling is performed by GA3 [10] in eTorii instead, which follows the principles of meshed trees [22,23]. The control frames of both RSTP and GA3 are illustrated in Figure 1.…”

“…The flooding of GA3 frames is performed until all network nodes are reached. This process is not performed if the switches receive HLMACs longer than the ones previously obtained, as they discard them to avoid loops [22,23]. The resulting assignment is illustrated in Figure 2.…”

Fast Fail-Over Technique for Distributed Controller Architecture in Software-Defined Networks

“…Sharma et al [55], [56] compared the protection and recovery approaches for inband OpenFlow networks and concluded that only protection grants a recovery period under the required 50 ms as stipulated by Multiprotocol Lable Switching Transport Profile (MPLS-TP) requirements for network restoration after failure detection with spans less than approximately 746 miles [41]. A recent work by Lopez-Pajares et al [37], proposed Amaru, a protocol that provides plug-and-play resilient in-band control for SDN with low-complexity and high scalability. The protocol uses hierarchical labeling to mask MAC address to simplify the routing tables and minimize the number of entries to one per path.…”

“…In this work, we trade off the simplicity of out-ofband for the quick update advantage of in-band operational mode [4], [12]. As summarized in [37], in-band control can easily scale with the size of the network without incurring high routing cost, and less prone to congestion due to the high capacity nature of the data plane links when compared to the out-of-band control. Further, the resiliency of in-band networks to link failure comes with no extra cost (i.e., providing secondary paths) since both data path and control path share the same link.…”