Testing Network Virtualization For Data Center and Cloud VERYX TECHNOLOGIES
Table of Contents Introduction... 1 Network Virtualization Overview... 1 Network Virtualization Key Requirements to be validated... 2 Intra Data Center Requirements... 2 1. Interaction between Virtual Environments and Non-Virtual Environments... 2 2. Traffic Isolation... 2 3. Stateful VM Migration... 3 4. Assuring Network Performance Guarantees... 4 5. High Availability and Resiliency... 4 6. Assuring Quality of Service... 5 7. Addressing Scalability Issues... 5 8. Ensuring Security and Applying Access Control policies... 5 9. Validating Auto Provisioning... 5 10. Ensuring Communication with Storage Area Networks... 6 1. Subnet Extension... 6 2. Assuring Network Performance... 6 3. Path Optimization... 7 4. VM Live Migration... 7 Conclusions... 8 Copyright 2002-2013 Veryx Technologies. Page ii
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Introduction In recent years, the demand for cloud-based data centers has grown dramatically, taking advantages provided by the cloud in terms of scalability and better operational efficiencies. But due to the growing and dynamic nature of the cloud paradigm, cloud service providers have been facing flexibility and scalability bottlenecks in providing elastic, multi-tenant cloud operations. Network virtualization has emerged as compelling solution to overcome these bottlenecks. This mandates that the providers of such solutions perform specialized testing to ensure that the network meets the cloud data center demands. This document discusses the key testing requirements for reliable network virtualization infrastructure and how Veryx assists the equipment vendors comprehensively verify their products and solutions for data center and cloud infrastructure requirements. Network Virtualization Overview Network Virtualization provides the capability to run multiple virtual networks infrastructure on the same physical network, thereby making the virtual network independent of the underlying physical network. This feature enables the cloud to provide better flexibility and scalability by reusing the addresses between virtual subnets. This flexibility motivates many enterprises to consolidate their workloads and create a private cloud data centers where they can easily move their workloads anywhere in the network which in turn increases their operational efficiencies. Further, this flexibility enables customers to easily move towards various cloud services such as Infrastructure as a Service (IaaS) and Software as a Service (SaaS) in public cloud infrastructure. Figure 1 - Network Virtualization Overview Copyright 2002-2013 Veryx Technologies Page 1
Network Virtualization Key Requirements to be validated Intra Data Center Requirements 1. Interaction between Virtual Environments and Non-Virtual Environments Network virtualization gives enterprise and data center infrastructure providers a high level of flexibility, scalability and programmability to meets their growing demands. Still there exists an interaction between virtual networks and legacy physical network for example, to connect to Storage Area Network (SAN) or to users connecting to data center. In all these cases, traffic needs to be forwarded through an Edge device across segments for appropriate transformation. It is critical to verify the data center performance bottlenecks and security polices, so that enterprises and virtualized data center infrastructure providers can ensure committed Service Level Agreements (SLAs) to their end-consumers. Figure 2 Interaction between Virtual Aware and Virtual Unaware Environments 2. Traffic Isolation Network virtualization significantly reduces both the capital expenditure (CAPEX) and operational expenditure (OPEX) through deployment of multiple tenant networks over a single physical network. To enable multi-tenant data center infrastructure, there needs to be complete address space isolation between tenant networks to provide logical separation for traffic sent by one virtual machine (VM) by the other. Virtualized data Copyright 2002-2013 Veryx Technologies Page 2
center infrastructure must implement the same services that are available over traditional dedicated networks, on logically partitioned networks with overlapping IP addresses. It is crucial to measure that the traffic forwarding is limited according to the defined traffic isolation policies. Figure 3 Traffic Isolation between Virtual Subnets 3. Stateful VM Migration Network virtualization enables enterprise and data center infrastructure providers to place workloads anywhere in the network and migrate dynamically across physical IP subnets The key challenge is that the existing IP configurations of workload need to be retained during/after migration for session continuity while still maintaining complete isolation between tenant networks. Virtualized data center infrastructure must assure continuity of services to consumers without disruption to current operations, when such migrations occur. It is crucial to measure the quality of experience (QoE) during migration process, in order to ensure that this does not suffer de-gradation beyond the acceptable limit. Copyright 2002-2013 Veryx Technologies Page 3
4. Assuring Network Performance Guarantees Network Performance is crucial for the data center network. With network virtualization, it becomes more crucial as workloads can dynamically join the virtual subnet from any of the locations. Virtualized data center infrastructure must be able to support the network performance characteristics according to the committed Service Level Agreements (SLAs) to consumers. It is crucial to measure the performance characteristics such as Jitter, Latency and Throughput of network under various instances such as migrating VMs and dynamically adding VMs. 5. High Availability and Resiliency High Availability and Resiliency are some of the key attributes for the virtualized data center network. The network should be highly fault tolerant and robust enough to handle any link or network component failure, through distributed architecture with support for multi-pathing and failover. Further, the network needs to support fast convergence and traffic re-routing functionalities. Virtualized data center infrastructure must ensure that the service down time is kept within the agreed limits. It is crucial to validate the robustness and resiliency of the devices in the network. Figure 4 High Availability and Resiliency support Copyright 2002-2013 Veryx Technologies Page 4
6. Assuring Quality of Service In the virtualized data center network, traffic handling and prioritization within and across virtual networks is crucial where the data center requires maintaining of Quality of Service (QoS) policy per tenant and per application. Virtualized data center infrastructure should meet the required performance guarantees for various tenants and service types. It is crucial to validate that the network provides proper Quality of Service (QoS) differentiation to various applications in a virtual network and appropriate Quality of Service (QoS) isolation between virtual networks. 7. Addressing Scalability Issues Network virtualization has emerged as a solution to overcome the scalable limitation imposed by a legacy physical network, especially VLANs (which are limited to 4,096). The virtualized data center infrastructure has to support scalability from a single server to tens of thousands of servers and from single virtual network to thousands of virtual networks and thus support very large scale deployments. It is crucial to measure the degree of scalability, while maintaining the required performance guarantees and the path isolation. 8. Ensuring Security and Applying Access Control policies Unlike a physical network where the topology is fixed, the virtualized network is dynamic. The virtual network is expected to undergo changes often due to VMs coming up, going down or moving to another location. The providers of virtualized data center infrastructure must ensure that the security policies are always up-to-date to eliminate any security flaws. It is crucial to validate the equipment enforces the necessary security policies and not be vulnerable to any attacks when the VMs are on the move. 9. Validating Auto Provisioning Since the virtualized data center is dynamic, manual provisioning and maintaining of the network adds more complexity to the network management team and highly error prone. The virtual network is expected to support programmatic provisioning when there are any changes in the network, which typically could be the case when VMs are migrated from one location to another. The providers of virtualized data center infrastructure must ensure that the network state is updated according to the changes. It is crucial to validate how equipment does the necessary provisioning dynamically without disrupting the existing services and policies upon any network changes. Copyright 2002-2013 Veryx Technologies Page 5
10. Ensuring Communication with Storage Area Networks With growing number of VMs in virtualized data center, the access to storage space is also proportionally growing either for data storage or for data recovery purpose. The virtual network is expected to provide a lossless connectivity to the storage network regardless of the location of the VMs in the data center. Since the Storage Area Network (SAN) is highly sensitive to latency, the providers of virtualized data center infrastructure must ensure the required performance guarantees for storage traffic as compared to server traffic. It is crucial to validate the equipment provides differential treatment to storage area access traffic, while preventing it from malicious attacks and support for resiliency. Data Center Interconnect Requirements 1. Subnet Extension Figure 5 Subnet Extension across Data Center 2. Assuring Network Performance Network Performance is the key in inter data center communications. It is especially critical when VM access the storage space from a different location. This typically happens when a VM that is provisioned to access a dedicated storage volume within the data center and moved to another location, is required to maintain the session state with the same storage area network. Further, since SAN is highly sensitive to latency, the providers of virtualized data center infrastructure must ensure the required performance metrics to keep the latency to its minimal value. It is crucial to measure that the data center equipment meets the performance characteristics such as Jitter, Latency and Throughput during virtual machines (VMs) migration across sites. Copyright 2002-2013 Veryx Technologies Page 6
Figure 6 VM Migration and native Data Center Connectivity 3. Path Optimization Due to Geo-Clustering and Subnet Extension across data centers, path optimization is crucial for VMs migrating across data centers. This is important for VM mobility in order to overcome sub-optimal routing issues, especially the bandwidth consumption intended for Data Center Interconnection. The providers of virtualized data center infrastructure must be able to track the virtual machines (VMs) movement and provide appropriate traffic forwarding path to reduce traffic black-holing. It is crucial to verify that the data center equipment ensures the path optimization for traffic between client to server or server to client or server to server when virtual machines (VMs) are on the move. 4. VM Live Migration Network virtualization provides a high level of flexibility where the virtual machines (VMs) can move to any servers in any locations. The providers of virtualized data center infrastructure are required to perform the required virtual machine migration procedures to maintain the session state of virtual machine (VMs) during its migration to/from a different site. Further, it is necessary to perform the required network policy enforcements and traffic re-routing support. It is crucial to verify that the data center ensures session continuity, network performance and policy enforcements during virtual machine (VM) live migration. Veryx Testing Approach for Network Virtualization Veryx helps in validating all the key requirements that are discussed in the above sections to ensure that the equipment vendor s equipment is ready for deployment in the virtualized network infrastructure. This is achieved through a unique testing approach. Some of them include Copyright 2002-2013 Veryx Technologies Page 7
Emulating topologies with several tenant networks, virtual machines (VMs) and Storage Area Networks (SAN) for various use case scenarios and measuring how well the device scales. Creating various real-time traffic profiles, simulating East-West and North-South traffic patterns to measure the performance characteristics of the device such as throughput and latency, load balancing through link aggregation hashing algorithms including MC-LAG, traffic isolation per domain using domain identifiers including VLANs, Virtual Subnet Identifiers (VXLAN and NVGRE), traffic prioritization based on the defined QoS policies etc. Simulating live migration of virtual machines (VMs) within the data center and verifying the continuity of VM sessions using various Network Virtualization Endpoint (NVE) technologies like NVGRE, VXLAN etc. Ensuring continuity in enforcement of security and access control policies, when VMs are dynamically migrated. Emulating network with multi-path support and verifying the support for subnet extension, end-to-end loop free layer 2 domain with any of the Layer 2/Layer 3 virtualization technologies including TRILL, SPB, and BGP/MPLS IP VPN. Simulating live migration of virtual machines (VMs) across data centers and verify virtual machines (VMs) session continuity, path optimization support, traffic re-routing support, enforcement of on the fly network polices etc. Simulating dynamic addition, removal and migration of virtual machines (VMs) and verifying the automatic provisioning of network state using automated network state management technologies including IEEE 802.1Qbg and VMTracer (Arista). Simulating network impairments and measure the service availability (High Availability) and system resiliency support. Conclusions Network equipment vendors are racing to provide their customers the service providers and enterprises the capability to take advantage of the speed and efficiency of cloud paradigms using network virtualization solutions. However, they face numerous challenges in ensuring adequate and quicker testing of their products without sacrificing quality. Veryx Technologies provides innovative Verification and Measurement Solutions for the global communications industry. Veryx Professional Services effectively complements and supplements customer testing teams efforts and also delivers higher efficiency and flexibility with its execution models. For more information regarding testing services for network virtualization and SDN technologies, contact Veryx. Copyright 2002-2013 Veryx Technologies Page 8
Veryx Technologies (www.veryxtech.com) is an innovative enterprise providing solutions that enhance product quality and testing efficiency. Veryx offers flexible, cost-effective products that enhance the Service Assurance capabilities of Ethernet Service Providers. Leading equipment vendors, rely on the ATTEST range of products for testing applications in Access, Carrier Ethernet, Data Center, Edge, Enterprise, Industrial Networking and Security domains for over a decade. The unique offerings from Veryx enable customers to reduce the timerequired-to-test and enhance their time-to-market www.veryxtech.com info@veryxtech.com AMERICAS: +1-408-850-1247 ASIA: +91 (44) 45 67 22 22 EUROPE: +44-203-371-8691 2002-2013 Veryx Technologies. Veryx and Veryx ATTEST are trademarks of Veryx Technologies. All other trademarks of respective owners are acknowledged. Copyright 2002-2013 Veryx Technologies Page 9