Белая книга для Cisco Cisco Prime Virtual Network Analysis Module (vNAM) 6.1

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2-2
Cisco Virtualized Multiservice Data Center (VMDC) Virtual Services Architecture (VSA) 1.0
Design Guide
Chapter 2      VMDC VSA 1.0 Design Overview
  Design Principles
Modularity—Unstructured growth is at the root of many operational and CAPEX challenges for data 
center administrators. Defining standardized physical and logical deployment models is the key to 
streamlining operational tasks such as moves, adds and changes, and troubleshooting performance issues 
or service outages. VMDC reference architectures provide blueprints for defining atomic units of growth 
within the data center, called PoDs.
High Availability—The concept of public and private “Cloud” is based on the premise that the data 
center infrastructure transitions from a cost center to an agile, dynamic platform for revenue-generating 
services. In this context, maintaining service availability is critical. VMDC reference architectures are 
designed for optimal service resilience, with no single point of failure for the shared (“multi-tenant”) 
portions of the infrastructure. As a result, great emphasis is placed upon availability and recovery 
analysis during VMDC system validation.
Differentiated Service—Generally, bandwidth is plentiful in the data center infrastructure. However, 
clients may need to remotely access their applications via the Internet or some other type of public or 
private WAN. Typically, WANs are bandwidth bottlenecks. VMDC provides an end-to-end QoS 
framework for service tuning based upon application requirements. This release adds consideration of a 
set of tools for application visiibility, control and optimization, enhancing the ability to provide 
application-centric differentiated services.
Multi-tenancy—As data centers transition to Cloud models, and from cost centers to profit center, 
services will naturally broaden in scope, stretching beyond physical boundaries in new ways. Security 
models must also expand to address vulnerabilities associated with increased virtualization. In VMDC, 
“multi-tenancy” is implemented using logical containers, also called “Cloud Consumer” that are defined 
in these new, highly virtualized and shared infrastructures. These containers provide security zoning in 
accordance with Payment Card Industry (PCI), Federal Information Security Management 
Act (FISMA), and other business and industry standards and regulations. VMDC is certified for PCI and 
FISMA compliance.
Service Orchestration—Industry pundits note that the difference between a virtualized data center and 
a “cloud” data center is the operational model. The benefits of the cloud – agility, flexibility, rapid 
service deployment, and streamlined operations – are achievable only with advanced automation and 
service monitoring capabilities. The VMDC reference architectures include service orchestration and 
monitoring systems in the overall system solution. This includes best-of-breed solutions from Cisco (for 
example, Cisco Intelligent Automation for Cloud) and partners, such as BMC and Zenoss.
VMDC VSA 1.0 leverages FabricPath as the Unified Data Center fabric. FabricPath combines the 
stability and scalability of routing in Layer 2 (L2), supporting the creation of simple, scalable, and 
efficient L2 domains that apply to many network scenarios. Because traffic forwarding leverages the 
Intermediate System to Intermediate System (IS-IS) protocol, rather than Spanning Tree (STP), the 
bi-sectional bandwidth of the network is expanded, facilitating data center-wide workload mobility.
For a brief primer on FabricPath technology, refer to:
http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/white_paper_c11-687554.pdf 
FabricPath benefits include:
Simplified Network, Reducing Operating Expenses
  •
FabricPath is simple to configure. The only necessary configuration consists of distinguishing core 
ports, which link the switches, from edge ports, to which end devices are attached. No parameters 
need to be tuned to achieve operational status, and switch addresses are assigned automatically.
  •
One control protocol is used for unicast forwarding, multicast forwarding, and VLAN pruning. 
Networks designed using FabricPath require less combined configuration than equivalent networks 
based on STP, further reducing the overall management needed for the solution.