1 Blockchain-based Decentralized Applications for Multiple Administrative Domain Networking Raphael Vicente Rosa and Christian Esteve Rothenberg Abstract—Evolving networking scenarios include multi- administrative domain network services as drivers of novel business opportunities along emerging operational challenges. As a potential approach to tackle upcoming requirements providing basic primitives to encompass analytics, automation, and distributed orchestration, we investigate blockchain-based Decentralized Applications (DApps) in the context of operational phases in support of multi-administrative domain networking. We present and discuss a generalized framework for multi- domain service orchestration using blockchain-based DApps and then showcase proof of concept prototype experiments based on best of breed open source components that demonstrate DApp functionalities as candidate enablers of multi-domain network services. We then analyze three use case scenarios pursued by ongoing work at Standard Development Organizations (SDOs), namely MEF, 3GPP, and ETSI NFV, discussing standardization opportunities around blockchain-based DApps. I. I NTRODUCTION Diverse 5G services envisioned (e.g., augmented real- ity, vehicular communications, IoT) call for advanced multi- administrative domain service deployments, open challenges arising from vertical customers of communication service providers [1] leading to complex distributed SLA-based or- chestration hazards. Stakeholders at different administrative domains are looking for shared revenue models from roaming scenario and vertical businesses [2]. For a given end-to-end network service, its realization would benefit from every per- domain segment being able to distributively contribute to the delivery and assurance of a given service supply chain (e.g., proof-of-relay attesting intermediary flow attributes such as throughput, latency, packet loss ratio, etc.), in addition to contractual operational workflows in case of SLA breaches. To attend decentralized non-trusting administrative domains in need of chained smart contracts (inter-domain transactions and billing) for consensus (composed SLAs), we advocate for the opportunities unlocked by a shared ledger of abstracted capabilities (end-to-end service slices) via blockchain-based Decentralized Applications (DApps) for multi-administrative domain networking. Such natively distributed and dynamic scenarios built for robustness and fault-tolerance are hardly ad- dressable by trusted centralized databases or intermediate mar- ketplaces (see Table I), as recognized by pre-standardization The authors are with School of Electrical and Computer Engineering (FEEC), University of Campinas (UNICAMP), Brazil research efforts and early commercial solutions. The main contribution of this article is establishing a walk- through from background baselines, via motivating perspec- tives and potential candidate strategies and implementation options to incorporate blockchain-based DApps into multiple administrative domain scenarios. Our proof-of-concept proto- type experiments of blockchain-based Multi-Domain Orches- trators (MdOs), demoed in [3], showcase smart contracts for lifecycle management of network services across administra- tive domains. Such argumentative baggage sustains our stan- dardization outlook discussion towards feasibility prospects of incorporating blockchain-based DApps into three Standards Developing Organization (SDO) use case scenarios. II. BACKGROUND CONCEPTS AND DEFINITIONS Following the Next Generation Mobile Networks (NGMN) Alliance terminology [2], “provider” refers to any entity that provides a service (e.g., Infrastructure, Platform, or Network as-a-Service), including an “operator” of some administrative domain. A provider may obtain benefits from offering service spare capabilities or resources to/from 3rd parties to enrich the services provided to its end customer. Henceforth, we refer to an administrative domain as the scope of jurisdiction of a provider. A MdO stands for the entity responsible for providing network service lifecycle operation/management across administrative (and technology) domains. A network asset consists of any resource (e.g., net- work function, virtualized environment, connectivity) available for a network service. A. Beyond Traditional IP Peering Further than Border Gateway Protocol (BGP), possible bi/multi-lateral partnership agreements among providers im- plementing Software Defined Networking (SDN) and/or Net- work Function Virtualization (NFV) technologies can result in complex end-to-end service deployments covering various net- work assets. Next, we formalize generalized network service operational phases in a multi-administrative domain setting as follows (see Fig. 1): 1) Discovery: consists in perceiving provider boundaries and the interconnections that might exist with direct or Decentralized Internet Infrastructure Research Group (dinrg) at https://datatracker.ietf.org/rg/dinrg/about/ and ITU Focus Group on Application of Distributed Ledger Technology (DLT) at https://www.itu.int/en/ITU-T/focusgroups/dlt/ - Accessed on 2018-05-01 e.g., Blockstack, A New Internet for Decentralized Apps at https://blockstack.org and, NKN, New Kind of Network at https://nkn.org - Accessed on 2018-05-01