Specifications

Copyright © 2009, Juniper Networks, Inc. 13
DESIGN GUIDE - Data Center LAN Connectivity Design Guide
Data Center Architecture Overview
Layered Approach
The typical enterprise network is built upon multiple levels of switches deployed in three general layers: access,
aggregation and LAN core.
Figure 4: The layered approach
Providing vital LAN services, these layers exist at various locations throughout the network, including data centers,
campus buildings and the data center. This document focuses primarily on the layers deployed in the data center.
Areas outside of that scope are presented when relevant to the discussion. For example, some data centers may
choose to collapse the aggregation layer into the core.
The access layer provides connectivity to the servers, applications, storage devices, and any IP or office automation
devices required in the data center facility.
The aggregation layer aggregates connections and traffic flows from multiple access-layer switches to core-layer
switches.
The core layer provides secure connectivity between aggregation-layer switches and the routers connecting to the WAN.
The WAN edge provides connectivity to the Internet and the WAN to enable remote connectivity.
Benefits
A multilayered architecture facilitates network configuration by providing a modular design that can rapidly and
economically scale. It also creates a flexible network on which new services can be easily added without redesign.
The layered approach also delivers separated traffic, balances load across devices and simplifies troubleshooting.
Challenges
Over the years, networks have grown bloated trying to address emerging bandwidth, throughput and port density
requirements by deploying multiple layers of low density, single-function legacy hardware, many of which are
redundant. These old solutions not only fail to meet the current data center requirements, but also add considerable
management complexity, reduce network availability, and drive up capital and operational expenses.
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Device Connectivity
Data Center Connectivity
DATA CENTER CAMPUS OR BRANCH
WAN
(MULTIPLE SPS)