Community Research and Development Information Service - CORDIS


ACINO Report Summary

Project ID: 645127
Funded under: H2020-EU.

Periodic Reporting for period 1 - ACINO (Application Centric IP/Optical Network Orchestration)

Reporting period: 2015-02-01 to 2016-01-31

Summary of the context and overall objectives of the project

Applications and verticals that support specific business processes, with their peculiar requirements and targets, will ultimately drive the evolution of telecommunications towards 5G and beyond. In the transport networking area, relevant business applications could be, for example, virtual machine migration, data backup (e.g. sensitive financial or social network data), distributed content delivery (e.g. video-on-demand, TV broadcasting), etc. In the last few years, they have evolved from simple requirements, that can be easily and cheaply met with a best-effort network and a reliable end-to-end transport protocol, to stringent requirements in terms of latency and jitter (e.g. financial transactions), bandwidth (e.g. video production over IP), reliability, security, etc.

Such applications operate on top of a three-layer structure. They generate traffic that is groomed at the IP/MPLS and/or OTN layers and finally transported at the optical layer. Despite these diverse requirements, the application’s traffic usually passes through a grooming layer, typically IP/MPLS, which aggregates multiple small flows into larger ones that can be cost-effectively supported by the bottom optical layer (sometimes there is also OTN, another grooming layer between the IP and photonic layers). The existence of these grooming layers results in an indirect relationship between the application layer and the transport layer, which implies an inaccurate mapping of application needs to the transport layer, since the requirements imposed by the grooming layer to the optical layer are the result of an aggregation of diverse applications with different needs. While offering the best possible service characteristics at the optical transport layer to each application is theoretically achievable (e.g. by using a fully meshed optical bypass virtual topology), it would be prohibitively expensive and energy-hungry. Therefore, a smarter approach is needed.

The ACINO (Application Centric IP/optical Network Orchestration) project proposes an application-centric approach, where the traffic of each application receives a tailored service at each layer of the transport network (potentially, all the way down to the optical layer), thereby overcoming the gap that the grooming layer introduces between application service requirements and their fulfillment in the lowers layer of the stack. This way the network becomes more efficient, since the grooming process is minimized and the optical resources are used efficiently to meet but not needlessly exceed the requirements of the applications. The applications, in turn, could exploit – and even be engineered to take advantage of – the on-demand and personalized reservation of network connectivity, resources, reliability, security, etc. As a result, the needs of emerging medium-large bandwidth-consuming applications will be catered to, while small flows that do not match the granularity of an optical service, can still be groomed together with other flows having similar requirements (i.e., classes). The ACINO concept is outlined in Figure 1.

ACINO focuses on the control aspects of networking, while trying to achieve its outcomes by leveraging the state of the art of transport technologies (both IP and optical). For this reason, the project exploits the Software-Defined Networking (SDN) approach in the context of multi-layer dynamic network control. Indeed, with its strong focus on the programmability aspects, SDN can produce evident benefits on the network operations and provide a powerful interface towards the applications, in line with the needs of the project. Such a joint control of different sets of network technologies spanning multiple layers has been referred by the project to as network orchestration.

In order to bring the envisioned concept to reality, the overall objective of ACINO is to develop and experimentally demonstrate an open-source IP/optical orchestrator that includes online planning and computation software modules exploiting advanced application-centric methods and algorithms, and exposes specific primitives towards the applications to easily map their needs to the service they will receive.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The project started with the investigation and characterization of the most relevant ACINO applications. As a target for the first year activity, the ACINO consortium decided to focus on three groups of applications: 5G (enhanced mobile broadband, massive machine-type communications, fronthaul services to enable Cloud RAN deployments), video (IPTV, Video on Demand, OTT video) and cloud (virtual machine migration or replication, database synchronization). These applications were analyzed, their requirements were identified and classified. To give an understanding of the different requirements, with a bird’s eye view, 5G applications may be very demanding in terms of latency, video applications may require specific features such as encryption and multicast services (beyond being bandwidth-consuming), while cloud applications may be very demanding in terms of peak capacity.

In order to satisfy the outlined requirements, the network resources should be configured and adapted accordingly. Therefore, the consortium identified the main network multi-layer operations that can be applied. The project looked at the technical advances observed in data plane technologies, by considering scenarios like Optical Transport Network (OTN) Wavelength Switched Optical Networks (WSON), Spectrum Switched Optical Networks (SSON) or Spatial Division Multiplexing (SDM). Furthermore, the project defined the reference network that will be used in the planning and techno-economic studies of the project.

The consortium then identified some case studies that can help in demonstrating the innovations produced by the ACINO project. Each case study is given by a combination of applications that receive a tailored service from the orchestrator, by resorting to one or more multi-layer network operations. As a result, six case studies were defined, which will show how the adoption of the ACINO concept can help to cater the needs of the applications in multiple scenarios (e.g. data centers, ultra-dense 5G networks, virtual CDN deployments), by enforcing the most proper configuration both at the packet and the circuit layers and by executing operations such as provisioning, in-operation planning, survivability, encryption.

In ACINO, such operations will be carried out by the network orchestrator. The consortium defined the overall architecture and the requirements of the orchestrator, as well as its interfaces and supporting network controllers. Moreover, a set of requirements for the controllers of the IP layer and of the optical layer that will enable multi-layer control were defined.

An overview of the main elements of the ACINO orchestrator platform is shown in Figure 2. The orchestrator interfaces with the outside world through two main interfaces. A North-Bound Interface (NBI) towards applications gives them the possibility to request network services with specific requirements such as latency, reliability, capacity etc., in the form of “intents”. Special applications, such as a Network Management System (NMS), may even interface with the online planning functionalities exposed by the orchestrator. Application intents provided over the NBI are then translated into a multi-layer service configuration utilizing both IP/MPLS and optical resources, which is pushed down to the underlying network layers through the use of South-Bound Interfaces (SBI) that are exposed by the control planes of the optical and the IP networks. The SBIs are used to push configurations to the network and to pull the network state or relevant alarm states from the networks being controlled.

More specifically, the orchestrator platform performs the following operations: (A) it gathers information on the underlying network layers using the SBI and stores it into a multi-layer network model; (B) it receives intents from applications through the NBI, maps them into an installable configuration for the underlying networks, and pushes such configuration down to the underlying network control planes via the SBI; (C) it receives planning requests from one or more Network Management System class applications through the NBI, computes the effects of the proposed changes and replies back to the requestor with the outcomes of the computation; optionally, it may also push the resulting configuration to the underlying network layer via the SBI.

With respect to the interaction with the applications, the consortium worked on a common definition of the key parameters that allow applications to explicitly specify requirements for the network services without delving into the details of the underlying technologies. Furthermore, a list of network primitives to be exposed to the applications has been provided. Such primitives can be combined to form intents in order to let the applications express their needs. Finally, the protocol requirements for the north-bound interface were studied and an intent engine/compiler design, including a finite state machine, has been suggested to process incoming intent requests from applications.

The intents are thus transformed into service requirements, then an optimal solution for the allocation of resources, based on the applications’ requirements, shall be found. To this account, the project spent some effort on the review of relevant approaches for multi-layer IP-optical resource allocation schemes. The strategy for the mapping of service requirements to multi-layer network resources was the main investigated aspect, since it is the heart of the application-aware allocation and optimization processes. The overall strategy has also defined the interfacing and exchange of information between the resource allocation and online planning modules with the remaining modules of the architecture. Moreover, the project activities led to the definition of the simulation platform to be used and the implementation of the simple networking scenarios that utilize the defined allocation options. The open source Net2Plan simulation platform has been chosen for the development and testing activities.

In parallel to such activities, the consortium reviewed the state of the art of SDN frameworks, in an effort to identify the best SDN framework that should be used as a basis to develop the ACINO orchestrator. Four framework solutions, namely the ABNO, OpenDayLight, ONOS and ODENOS, emerged as the most promising for the development of the ACINO concept. The consortium identified ONOS to be the most suitable framework for serving as the basis of the implementation of the ACINO orchestrator. Moreover, the elements of the ACINO architecture were mapped on existing ONOS components, and the required new components that would be developed in the ACINO project were identified. Furthermore, a review of different multi-layer network models (proposed in multiple standardization bodies) was performed.

This latest effort led to the start of the implementation activities, with the setup of an emulation platform. Furthermore, different environments that provide optical and packet systems were identified. The initial implementation work was focused on the network primitives for the designed intent-driven interface, the multi-layer network model and the southbound interfaces towards the IP and the optical data planes.

The ACINO orchestrator will be finally demonstrated on top of a physical testbed, according to the defined case studies. The testbed has been designed and validated. The project partners also performed an initial study where the various case studies were mapped to potential configurations over the testbed setup to ensure that the infrastructure can be successfully used to validate the ACINO concept.

Lastly, the consortium has been very active in dissemination and communication, with more than fifteen different dissemination activities (articles, presentations, tutorials, etc.) in the first reporting period.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The ACINO project aims at addressing the mismatch between the service provided by the transport layer and the needs of verticals/applications, by creating multi-layer services tailored to the requirements of the applications. In order to concisely present the impact of the project, we will follow a top-down description.

Verticals and applications owners will definitely benefit from a transport ecosystem that is capable of “talking their language”. ACINO’s concept, based on application-driven transport services, will open the door for European verticals, content providers and web service providers to better compete with today’s US-based service companies thanks to the higher efficiency of the proposed solution, without requiring any detailed knowledge on how the network is operated. This will ultimately affect the experience of end users, predominantly due to the better ability to control the required service characteristics all the way down to the optical layer.

ACINO will help European service providers, like TID, to identify new application-centric service offerings specifically geared towards high throughput applications, such as cloud applications, video applications, and social network applications. Indeed, they will be able to offer more cost effective services, with a local scope, relying on European data centers, instead of today’s web services that require a more global scope, a context in which US data centers are predominant. This will also allow service providers to rise up in the food chain and provide value-added services instead of just transport services, increasing their profitability.

According to the envisioned approach, network operators will be able to transfer, protect and secure large amounts of data generated by applications in a more effective way, by executing operations initiated by the applications themselves. Thanks to the proposed SDN-based orchestration solution, they will be able to easily deploy network applications using the bare minimum of resources needed, thus adding value to their offering. Network operators will also reduce the cost of running the network by taking advantage of the increased energy efficiency promised by the ACINO approach. Indeed, when possible, applications’ traffic will be mapped directly onto a spectrum slice. Even when the grooming layer is still used, its use is limited to grooming of similar classes of traffic from one location to another location over a dedicated spectrum slice. This will typically imply a single hop in the grooming layer, since intermediate grooming will not be needed. Such a limited use of the grooming layer will drive the solution away from large multi-chassis grooming nodes, and towards smaller, less power hungry nodes. Since the electrical grooming layer (especially the IP layer) accounts for a significant fraction of the energy consumed by the network, the ACINO approach will significantly reduce the energy consumed by the network.

From the technological perspective, ACINO is based on the most advanced state of the art of packet and circuit networking capabilities, in the form of adaptive networks, which can use the network resources in a flexible manner. The desired flexibility can be obtained either at the electrical layer, by leveraging the capabilities of IP routing or OTN switching, or at the optical layer, by introducing novel technologies such as “sliceable transponders”. Regarding the former, a promising impact of ACINO is the reduced need for very scalable grooming nodes, opening the door for European equipment vendors building routers and OTN switching but lacking the scaling capabilities provided by leading vendors in this space (which are predominantly US based). With respect to the latter, sliceable transponders represent a method for splitting up a single transponder to form multiple “virtual transponders” that can provide separate optical connections at a finer granularity than the full physical transponder. One of the factors slowing down the adoption of sliceable transponders is that they require significant commercialization effort, but do not provide sufficient value in many networks, since the aggregation layer (IP or OTN) can create large links and fill them up with aggregated traffic. ACINO can justify the application of sliceable transponders as an effective mechanism to perform service differentiation at the optical layer, without requiring a traditional service grooming layer, such as OTN or IP. Conceptually, this can prove the value of sliceable transponders and drive their commercialization; however, given the lack of availability of these components within the project, their usage will not be demonstrated in the physical testbed. Furthermore, while ACINO does not aim at increasing the speed of interfaces beyond the state of the art as its research focus is not the hardware of such transponders, it does aim at better utilizing those interfaces by allowing them to be shared between multiple applications with different requirements. As a result, the business case for building higher speed interfaces could be stronger with ACINO since such interfaces can be well utilized from the beginning.

Therefore, a successful ACINO project will provide strong motivation for increasing the capabilities of the network, giving European system vendors such as ADVA and subsystems/component vendors an advantage in building an alternative food chain geared towards more flexible solutions. Of course, the knowledge gathered in the project on this topic will also be guide network operators in their investments.

ACINO spans different technological domains (application, IP/OTN, DWDM). The proposed solution is based on a network orchestration software built upon an open-source framework that will exploit the designed algorithms to satisfy the requirements of the applications and will dynamically control the data plane of the aforementioned domains. The data plane control will either happen by direct interaction with the network devices or by relying on the control software provided by the equipment vendors. The development of the control framework will provide a valuable feedback to equipment vendors about the relevant control features that are useful for external orchestrators. Moreover, the knowledge gathered with the development of the orchestrator will give to control plane vendors and consultancy providers, such as CREATE-NET and ACREO, and SDN application developers, such as SEDONA, an advantage in understanding the commercial viability of various multi-layer application use-cases and the know-how to develop the required control software for them. Also, research institutions like AIT and CREATE-NET will be able to identify promising research directions in algorithms for optimization of networks that are application centric. It should also be noted that the usage of and the contribution to open source tools, such as the ONOS controller, is expected to foster the emergence of industry open standards.

With respect to the applicability of the ACINO concept, this is not limited to backbone transport networks: in fact, it can ensure that specific 5G requirements can be satisfied end-to-end, on a per-application basis. From the operational perspective, this can be done either by coordinating the ACINO network orchestrator with the controller and resource manager of the mobile network, or by adopting (and adapting) it for the transport segments of the 5G network (i.e., fronthaul and backhaul).

To summarize, the expected impact of ACINO can be decomposed into the following points:
● Enable transport network services directly satisfying the application’s needs;
● Prove the value of dynamic and elastic optical technologies;
● Tackle the lack of dynamic control of transport networks by means of automated SDN-based multi-layer resource orchestration;
● Reduce energy consumption by bypassing the grooming layer;
● Foster the emergence of open industry with an open source and vendor-agnostic approach;
● Disseminate the results in high-impact journals and major conferences.

Related information

Record Number: 186604 / Last updated on: 2016-07-14
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