Robert Szabo

Resource Management in Diffserv (RMD): A Functionality and Performance Behavior Overview

The flexibility and the wide deployment of IP technologies have driven the development of IP-based solutions for wireless networks, like IP-based Radio Access Networks (RAN). These networks have different characteristics when compared to traditional IP networks, imposing very strict requirements on Quality of Service (QoS) solutions, such as fast dynamic resource reservation, simplicity, scalability, low cost, severe congestion handling and easy implementation. A new QoS framework, called Resource Management in Differentiated Services (RMD), aims to satisfy these requirements. RMD has been introduced in recent publications. It extends the IETF Differentiated Services (Diffserv) architecture with new admission control and resource reservation concepts in a scalable way. This paper gives an overview of the RMD functionality and its performance behavior. Furthermore, it shows that the mean processing delay of RMD signaling reservation messages is more than 1330 times smaller then the mean processing delay of RSVP signaling reservation messages.

Towards Unified Programmability of Cloud and Carrier Infrastructure

The rise of cloud services poses considerable challenges on the control of both cloud and carrier network infrastructures. While traditional telecom network services rely on rather static processes (often involving manual steps), the wide adoption of mobile devices including tablets, smartphones and wearables introduce previously unseen dynamics in the creation, scaling and withdrawal of new services. These phenomena require optimal flexibility in the characterization of services, as well as on the control and orchestration of both carrier and cloud infrastructure. This paper proposes a unified programmability framework addressing: the unification of network and cloud resources, the integrated control and management of cloud and network, the description for programming networked/cloud services, and the provisioning processes of these services. In addition proofs-of-concept are provided based on existing open source control software components.

Nonrate-proportional weighting of generalized processor sharing schedulers

This paper is concerned with GPS-based packet schedulers which are very important elements of guaranteed QoS networks. After recalling the basic properties of generalized processor sharing we introduce a novel approach to calculate tighter delay bounds than given in the former works of Parekh et al. (1993, 1994). This not only allows better utilization of networks resources but supports basis for arbitrary weighting of sessions. An efficient and numerically inexpensive algorithm for computing these bounds is also presented herein. Further we relax the rate-proportional weighting constraint and show that our delay bound calculation is applicable for any arbitrary (nonrate-proportional) weighted GPS system. Numerical examples demonstrate the flexibility of our algorithm in terms of adjusting delay and bandwidth easily between theoretical bounds. This approach is a very important step towards avoiding bandwidth-delay coupling which is a well-known problem of GPS-based rate-proportional servers.

Elastic network functions: opportunities and challenges

Network function virtualization (NFV) and software defined networking (SDN) are key technology enablers for cost reductions and new business models in networking. The possibility to automatically and dynamically scale network services at run time is one of the main claims of NFV. Elastic NFV could be similar to what elastic cloud services provide for compute, with pay-per-use cost models for customers. However, control of resources for elastic services is far from trivial. We show how current NFV and SDN architectures could support elastic resource services for network functions (NFs). We reveal that the current NFV architecture does not allow recursive resource orchestration, therefore preventing resource scaling requests from being handled by a resource orchestrator overseeing the entire domain where an NF is executed. We introduce a logical centralization of joint compute and network resource orchestration as a UNIFY framework, which enables direct control of elastic resources for the NFs. We show opportunities and challenges associated with such an architecture.

Severe Congestion Handling with Resource Management in Diffserv on Demand

Quality of Service (QoS) for the Internet has been discussed for a long time without any major breakthrough. There are several reasons, the main one being the lack of a scalable, simple, fast and low cost QoS solution. A new QoS-framework, called resource management in differentiated services (RMD), aims to correct this situation. This framework has been published in recent papers and is extending the IETF differentiated services (diffserv) architecture with new admission control and resource reservation concepts in a scalable way. This paper focuses on proposing and investigating two resource reservation solutions on the problem of severe congestion situation within a diffserv-aware network utilizing an admission control scheme called Resource Mananagement in Diffserv (RMD). The different severe congestion solutions are compared using extensive simulation experiments.

Multi-Domain Service Orchestration Over Networks and Clouds: A Unified Approach

End-to-end service delivery often includes transparently inserted Network Functions (NFs) in the path. Flexible service chaining will require dynamic instantiation of both NFs and traffic forwarding overlays. Virtualization techniques in compute and networking, like cloud and Software Defined Networking (SDN), promise such flexibility for service providers. However, patching together existing cloud and network control mechanisms necessarily puts one over the above, e.g., OpenDaylight under an OpenStack controller. We designed and implemented a joint cloud and network resource virtualization and programming API. In this demonstration, we show that our abstraction is capable for flexible service chaining control over any technology domains.

VBaaS: VNF Benchmark-as-a-Service

When rolling out Network Function Virtualization (NFV) services, resource monitoring becomes a critical task subject to different cost-accuracy tradeoffs depending on whether continuous monitoring or more static infrastructure resource views are taken. In this context, we propose Virtualized Network Functions (VNF) Benchmark-as-a-Service (VBaaS) to enable not only run-time resource evaluation but also test-before-deploy opportunities for VNFs and NFV Infrastructures. We describe the motivation behind VBaaS and its main value proposition for a number of use cases around the orchestration tasks of VNF Forwarding Graphs We present the main components of VBaaS along their system interactions and interfaces, discussing the main benefits of adopting VBaaS and open research issues. Addressing the identified challenges and finalizing our proof of concept VBaaS are our main ongoing work activities.

State correction after re-routing with reduced state resource reservation protocols

Recently, a new working group - Next Steps In Signalling (NSIS) - was established within the IETF to develop a general signalling protocol primarily to support QoS resource reservation. Two main operation modes have been clarified: stateful and reduced state. The first mode relies on per flow-state information in all interior nodes while the other uses aggregated states. Stateful operation is based on the resource reservation protocol (RSVP), while reduced state operation will be similar to the resource management in a Diffserv (RMD) framework. With the use of aggregated states instead of per-flow granularity, one looses fine control over resources but derives a scalable and more efficient protocol. However, some problems need new handling mechanisms. In this paper, we discuss the problem of re-routing from the aspect of reduced state resource reservation. We show how quickly and easily RSVP handles such situations but reduced state solutions like RMD require new mechanisms for a quick reaction. We propose and analyse several solutions.

Analysis of end-to-end multi-domain management and orchestration frameworks for software defined infrastructures: an architectural survey

Over the last couple of years, industry operators associations issued requirements towards an end-to-end management and orchestration plane for 5G networks. Consequently, standard organisations st ...

Orchestration of Network Services across multiple operators: The 5G Exchange prototype

Future 5G networks will rely on the coordinated allocation of compute, storage, and networking resources in order to meet the functional requirements of 5G services as well as guaranteeing efficient usage of the network infrastructure. However, the 5G service provisioning paradigm will also require a unified infrastructure service market that integrates multiple operators and technologies. The 5G Exchange (5GEx) project, building heavily on the Software-Defined Network (SDN) and the Network Function Virtualization (NFV) functionalities, tries to overcome this market and technology fragmentation by designing, implementing, and testing a multi-domain orchestrator (MdO) prototype for fast and automated Network Service (NS) provisioning over multiple-technologies and spanning across multiple operators. This paper presents a first implementation of the 5GEx MdO prototype obtained by extending existing open source software tools at the disposal of the 5GEx partners. The main functions of the 5GEx MdO prototype are showcased by demonstrating how it is possible to create and deploy NSs in the context of a Slice as a Service (SlaaS) use-case, based on a multi-operator scenario. The 5GEx MdO prototype performance is experimentally evaluated running validation tests within the 5GEx sandbox. The overall time required for the NS deployment has been evaluated considering NSs deployed across two operators.