Specifications

2 Copyright © 2009, Juniper Networks, Inc.
DESIGN GUIDE - Data Center LAN Connectivity Design Guide
Table of Contents
Executive Summary .................................................................................5
Introduction ........................................................................................5
Trends and Challenges........................................................................... 6
Centralization of Data Centers................................................................. 6
Server Consolidation ........................................................................ 7
Virtualization ............................................................................... 7
Storage.................................................................................... 7
Service Oriented Architecture (SOA) ............................................................ 7
Software as a Service (SaaS) .................................................................. 8
An Increasingly Decentralized Workforce........................................................ 8
Green and Environmentally Friendly Data Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
The Proliferation of Unified Communications .................................................... 8
Increasing Focus on Security.................................................................. 8
Data Center Network Design Considerations ........................................................ 9
Services Required in the Data Center........................................................... 9
High Availability (HA)......................................................................... 9
Visibility .................................................................................. 10
Network Connectivity ....................................................................... 10
Security .................................................................................. 10
Policy and Control .......................................................................... 11
Quality of Service (QoS) ..................................................................... 11
High Performance.......................................................................... 11
Juniper Network Design Approach ................................................................ 11
Data Center Architecture Overview ....................................................................13
Layered Approach .............................................................................. 13
Benefits .................................................................................. 13
Challenges................................................................................ 13
A Network Revolution ...............................................................................14
Data Center Access Layer ...........................................................................14
Access Layer Design Considerations .............................................................. 15
Application and Server Architectures .......................................................... 15
Benefits and Challenges of the Three-Tier Model................................................ 15
Server Virtualization ........................................................................ 16
Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Power over Ethernet (PoE)................................................................... 16
High Availability (HA)........................................................................ 16
VLAN and Spanning Tree Protocol (STP) ....................................................... 17
Using Layer 2 versus Layer 3 at the Access Layer................................................ 18
Physical Deployment: Top-of-Rack vs. End-of-Row .............................................. 19
Storage Connectivity........................................................................ 19