Ensuring end-user quality in NFV-based infrastructures Leveraging distributed NFV cloud nodes to provide instant assessment of end-user experience EXECUTIVE SUMMARY Compute resources for virtual network functions are becoming available not only inside data centers, but also on mobile base stations, access network devices and dedicated rack nodes providing cloud-in-a-box functionality. For efficient service assurance and troubleshooting in these distributed and virtual environments, it is recommended to utilize virtualized test and measurement tools that eliminate field engineer efforts and save substantial hardware expenditures, reducing total cost to an order of magnitude less. Netrounds is such an NFV-based toolbox that is easily deployed at any remote location through ordinary NFV cloud orchestration. With a minimum of efforts, and in just a few minutes, any organization can initiate instant NFV service chaining assurance or perform long-term end-user quality assessment and monitoring, all in line with relevant international standards from ITU, IETF and the Metro Ethernet Forum (MEF).
INTRODUCTION Practically every IT professional, including network engineers, have embraced virtualization technologies these days. Network providers and operators, as well as enterprise IT, are now discovering the great benefits by virtualizing not only the actual servers in their data centers, but also the whole infrastructure including resources for networking, storage and compute. This is what Network Functions Virtualization (NFV) is all about. NFV and Software Defined Networks (SDN) promise to make life easier and more efficient for network engineers by hiding the underlying complexity through abstraction layers. However, the underlying complexity still increases exponentially and problems that affect end-users experience of services are still likely to occur. Finding and fixing these problems is a challenge that has to be addressed. No service provider has a strong preference towards spending resources on quality assurance and troubleshooting. But as long as problems occur, these efforts are necessary to keep and develop the business. So rather than cutting these unwanted costs for service quality assurance completely, a more preferred way is to find solutions that drastically reduce them. Netrounds enables substantial cost savings thanks to: Elimination of hardware costs by using downloadable appliance software, suitable for NFV deployments Reduction of manual tasks through built-in automation support Enhancement of productivity thanks to unparalleled ease of use Alongside NFV and SDN as being very strong trends, the IT industry has also seen an increasing momentum for using Software-as-a-Service (SaaS), rather than deploying traditional on-premise software. The main drivers for SaaS have been alleviation of internal staff for platform maintenance and centralized management and access, as well as savings in up-front investment costs. SaaS, combined with virtual network functions, is a use case identified by ETSI and referred to as Virtual Network Function-as-a-Service, VNFaaS. ETSI has had the enterprise customer in mind as the actual end-consumer of the VNF service, for instance a virtual firewall. However, with Netrounds it is now possible for network operators themselves to become users and consumers of virtualized network testing and monitoring as a service. When it comes to professional service assurance and troubleshooting solutions suitable for telco environments, there have not been any SaaS alternatives available on the market until Netrounds was launched. Based on a subscription-based SaaS offering, Netrounds transforms the test and measurement industry in the same way as Salesforce did for Customer Relationship Management (CRM) solutions more than 10 years ago.
THE CHALLENGE In order to reduce churn, operators need to deliver high service quality and performance to their end-users. Therefore, real-time network performance metrics are needed to understand how quality demanding services such as IPTV, video conferencing and unified communications are experienced by their end-users. Existing 5 minute aggregate performance statistics available on network devices lack granularity and do not correlate well with delivered service quality. Hand-held or portable tools, on the other hand, are better suited for measuring end-user experience. However, these are built on custom hardware making them very expensive and difficult to distribute in larger scale. In a virtualized network, another complicating factor is that it is difficult, or even impossible, to attach physical hardware test devices into a virtual switch, for instance. In addition, these hardware tools are often tailored for one single service (like IPTV), making complete assessment and measurements of all offered services even more costly since multiple hardware devices are needed at each location of interest. Not to mention that with hand-held tools there is a need for hands holding them on-site, leading to expensive travelling and costly field efforts. The consequence of the above is that it often takes several weeks before problems are diagnosed and fixed, leading to lower customer satisfaction and increased risk of churn. Therefore, operators need tools that can be instantly deployed at strategic locations on their networks, quickly providing insights into end-user quality experience, delivered at a price point that is affordable.
SOLUTION OVERVIEW Netrounds is a SaaS solution that leverages public cloud infrastructure for central control and storage, combined with distributed x86 probe appliances to provide IP network insight and on-demand testing capabilities. These probe appliances are suitable for bare metal machines as well as for virtual hardware. In Figure 1, an overview of Netrounds system architecture is shown. The components shown as orange boxes labeled Netrounds Probe and Netrounds NFV Probe are in fact identical machine images. Remote control Active test traffic Live traffic monitoring Figure 1. Overview of the Netrounds system architecture. By downloading and launching one or several Netrounds probe machine images on any x86 targets, a network engineer can quickly and conveniently work through Netrounds' cloudbased GUI/portal to remotely perform distributed troubleshooting tests and even monitor quality proactively over time (SLA monitoring). Probes can be located on any physical or virtual Ethernet port in the network for interactive testing in labs and field trials with in-production monitoring. The probe image could be seen as a remotely controlled toolbox for network engineers. Tools included in the image support Metro Ethernet Forum and ITU-T Y.1564 service activation tests, access security tests, as well as tools for IPTV MPEG analysis, synthetic traffic generation of IPv4/IPv6 and a full stack SIP implementation with both signaling and media streams. Netrounds probes are purely software-based making them well suited as a virtual network function for test, measurement and monitoring.
SOLUTION DETAILS Unlike traditional handheld devices and hardware network testing tools, Netrounds is a complete system. This means it has multi-user support, as well as a centralized server for providing a single location to manage a large number of distributed measurement probes, as well as for storing and analyzing measurement results. The centralized server also provides a software repository for automatic updates of all probes, alleviating internal IT staff to manually maintaining and upgrading the embedded software. Netrounds leverages public cloud infrastructure for hosting its centralized servers. This means that the service is always accessible, regardless of location, as long as there is ordinary Internet connectivity. The solution is based on a multi-tenant model, which in turn allows for highly competitive pricing for accessing the service. For security reasons, all probes utilize encrypted communications for interacting with the server through a firewall-friendly scheme. Netrounds and its relation to SDN and NFV In a completely virtual world, there are no suitable physical interfaces where traditional test and measurement devices could be connected. Therefore, measurement devices implemented in software are required instead of their traditional hardware counterparts. As shown in the upper part of Figure 2, Netrounds NFV probe appliances can be launched with direct interface attach toward virtual switches, such as Open vswitch. Figure 2. Overall view of Netrounds and how it relates to SDN and NFV.
An orchestrator component typically handles deployment of machine images on the compute resources of the NFV infrastructure, as shown in green in Figure 2. This orchestration is also responsible to launch Netrounds NFV probe appliances at requested infrastructure locations. Note that these locations could extend far beyond the datacenter, to include network devices such as LTE base stations with available NFV compute resources. As also shown in Figure 2, configuration and provisioning of network connections between VMs or end hosts in an SDN environment is normally done by incorporating an SDN controller, such as OpenDaylight. The actual configurations are executed over the OpenFlow protocol towards both physical and virtual switches. In an SDN/NFV environment, a considerable portion of the bits is shuffled directly between VMs and VNFs without ever leaving the infrastructure. However, a real-world deployment still relies on an underlying interconnecting physical network, built on hardware. This means that any test and monitoring system has to be capable of measuring both across the virtual domains, as well as across the physical hardware domains. As shown in Figure 2, Netrounds is a solution that supports the combination of physical and virtual deployment. Measuring inside the virtual domain ( East-West ) In some real-world scenarios, traffic might not ever leave to the outer world. An example of this could be traffic between distributed back-office servers handling post-processing of customer data. In this scenario, the performance of the vswitch could quickly become the critical factor if the bandwidth requirements exceed the capacity of the vswitch. As shown in Figure 3, Netrounds probe appliances could be launched either on the same or on different hypervisors to measure achieved performance and long-term behavior of the traffic through the vswitch (blue arrow). The same probes can also be used to request and analyze response times and other performance metrics from services produced by other appliances in the same virtualization (green arrow). Figure 3. Measuring in the "East-West" direction between VMs.
Measuring across virtual and physical domains ( North-South ) In many cases, traffic originates from end-users (or clients) in the physical world. To resemble this scenario, a combination of physical and virtual probes is required. The physical probes could either be attached close to the end-user in the access or aggregation networks. For instance, a probe could be attached on the same aggregation switch as base stations or DSLAMs are connected. Probes could also be connected to unused switch ports of the top-of-rack (ToR) switches in the data center. Regardless of actual deployment, the main purpose of North-South measurements is to gain knowledge about end-user experience by measuring traffic traversing many different physical network devices as well as a potentially complex chain of various virtual network functions, such as WAN accelerators, firewalls and deep packet inspection devices. The physical part could include Internet core routers, peering routers, distribution switches, data center aggregation switches, mobile backhaul networks and even top-of-rack switches. Figure 4. Measuring in the "North-South" direction. Data plane tests and measurements Regardless of the East-West or North-South scenarios as explained above, there are three different types of data plane measurements that could be performed: 1. Using active synthetic traffic between probes Hub and spoke or mesh topologies High performance and reliable multi-stream generation of TCP and UDP using IPv4 and IPv6, up to 10 Gbit/s Metrics for loss, jitter, one-way delay Useful for QoS validation and service turn up testing according to ITU-T Y.1564 and Metro Ethernet Forum
2. Measuring actively towards real-world services Measuring like an end-user, from the end-users perspective Requesting content from IPTV streaming servers for MPEG analysis Measuring uptime response times and latencies towards common services such as HTTP and DNS Initiating sessions through SIP servers to measure signaling performance as well as media quality (MOS) 3. Passively capturing and analyzing traffic Remote traffic capturing on any probe interface, attached to either physical or virtual switches Processing of packet capture files in Wireshark Analysis and statistics of network traffic content In Netrounds, all these three types can be performed concurrently. BUSINESS BENEFITS Netrounds is instantly deployed, easy to use and quickly helps to solve IP network issues. Network operators with NFV-based network infrastructures can start remote troubleshooting within minutes, anywhere in the world. Automated tests and diagnostics can be initiated centrally, alleviating physical delivery of test equipment and involvement of staff in the field. This instant troubleshooting reduces time and cost to solve complicated customer issues with up to 90%. Vendors of cloud infrastructures can easily leverage Netrounds as a powerful virtual network function in their NFV ecosystem to improve the ability to test and monitor services, shorten time for acceptance testing and overall strengthen its portfolio. For end-users, Netrounds helps ensuring that their everyday connected lives go on without any interruptions. In any unexpected situation, end-users can rest assured that their service providers have the best available tool to quickly find and fix any problem.
SUMMARY Compute resources for virtual network functions are becoming available not only inside data centers, but also on mobile base stations, access network devices and dedicated rack nodes providing cloud-in-a-box functionality. For efficient service assurance and troubleshooting in these distributed and virtual environments, it is recommended to utilize virtualized test and measurement tools that eliminate field engineer efforts and save substantial hardware expenditures, reducing total cost to an order of magnitude less. WHERE TO GET FROM HERE Gone are the days when it took enormous field efforts to initiate remote troubleshooting and measurements of end-user experience. This is now part of the history. Within just minutes, you are able to get started with your own end-user quality assurance. Just navigate to www.netrounds.com and signup for your own account and leave the history behind.
Netrounds offers a reliable and easy-to-use network quality assurance solution, available from the cloud as a SaaS subscription. Netrounds helps getting in-depth understanding of network performance and provides actionable metrics on end-user experience. More than 170 network operators, enterprises and consultants worldwide use Netrounds to increase operational efficiency, reduce capital expenditures and deliver high end-user experience Founded in 2007, Netrounds is headquartered in Luleå, Sweden, with offices in Singapore and Boston. NETROUNDS SOLUTIONS AB Storgatan 7 972 38 LULEÅ, SWEDEN Phone +46 920 420015 www.netrounds.com Copyright 2014, Netrounds. All rights reserved. This document is issued to provide information only and the content is subject to revision without notice due to continued development. The product and services described are subject to availability and change without notice.