Specifications

DESIGN GUIDE - Data Center LAN Connectivity Design Guide

Figure 19: JUNOS Software—The three ones: one source code, one train, and one modular architecture

Modular Processes

The JUNOS Software is a completely modular operating system, enabling a functional division of labor for seamless

development and operation of many advanced features and capabilities. By partitioning the software system, tasks

are broken into manageable subsets that interact infrequently and provide new levels of fault-tolerance. Unlike

monolithic operating systems, each key JUNOS Software function executes as an independent process and runs

in its own protected memory space. Loading or executing one doesn’t affect the others. One daemon can restart

independently without disrupting another or forcing a full system crash or restart. A benefit of this approach is the

ability to maintain full control of the switch or router at all times. Because of the separation of control, forwarding

and services, filters can be added in real-time to thwart a Distributed Denial of Service (DDoS) attack.

Rollback Capability

JUNOS Software also offers error-resilient configuration that prevents operators from inadvertently bringing

down the data center network. IT must explicitly commit changes after entering and reviewing all modifications.

If a configuration change causes loss of connectivity to the device and no follow-up confirmation is provided, the

device automatically reverts back to the previous configuration, restoring connectivity—saving time and ensuring

Link-level HA. In addition to automatically checking for errors or incorrectly constructed configurations that could

cause potential problems, JUNOS Software provides a rollback command to quickly restore any of the 50 prior

configurations.

Advanced Features

The JUNOS Software also provides a broad spectrum of advanced routing and security software features such as

stateful firewall, IPsec, MPLS and IPv6 without requiring an additional software license. In addition, the JUNOS

Software provides comprehensive QoS functions to classify, prioritize and schedule traffic for applications such as

VoIP. When Virtual Chassis technology is used, the JUNOS Software enables bidirectional forwarding detection for

early detection of node or link failures.

Benefits

By running a common operating system, these Juniper solutions dramatically reduce maintenance and management

overhead while ensuring a consistent feature set across all products, as well as a consistent implementation and

management of those features. This equates to time savings in all categories of operations. In addition to a reduction

in training time, the inherent interoperability across all platforms greatly simplifies new feature deployment,

software upgrades and other network modifications. A single consistent code set also enables customers to

qualify and deploy just one release. For many customers, the testing time of a new release is cut from what was

months down to just a few weeks. JUNOS Software also provides features to facilitate fast restoration of previous

configurations.

Impact

In an independent study conducted in 2007, Lake Partners quantified the time savings Juniper Networks customers

experienced using the JUNOS Software across a number of common network operational tasks. The results are

presented in Table 2:

J Series

TX Matrix

ONE OS ONE RELEASE ONE ARCHITECTURE

9.0

9.1 9.2

Module

Frequent releases

API