Chapter 3. Juniper Networks Router Architecture


When the routers produced by Juniper Networks first hit the market in 1998, they brought simplicity of design, a logical UNIX-style CLI, and robust troubleshooting tools. The engineers who designed the routers wanted to build a device that made sense. In doing so, they filled a void in the market and appealed to other engineers who wanted a router that moved packets through as quickly as possible.

Juniper Networks' product offerings come in the form of the M-Series routers. The M40 was the first router of its kind capable of scaling to meet current Internet needs. The initial M40 release was based on the Internet Processor I. The Internet Processor I was the fundamental core of the packet forwarding engine (PFE). The PFE consisted of a shared memory, a single forwarding table, and a one-write, one-read architecture. The entire PFE was capable of forwarding 40Mbps, more than 100 times the capacity of other available router architectures at the time.

Although the M40 was quite progressive, Juniper Networks was able to improve on its available functionality by upgrading the processor, raising the available memory, adding redundancy, and including the ability to filter traffic through ACLs in later iterations of the product.

This chapter introduces you to the router models and architectural differences of each product. In addition, we will describe each hardware and software piece of the router and explain how that piece contributes to the overall logic of the device. This will include the routing engine, the PFE, the switching fabrics and control boards , the interfaces available, and the differences between the available router models. It will also include an explanation of the router's boot process and how to upgrade the JUNOS software.

Since the architecture and operating-system commands of these routers differs from those of other vendors , such as Cisco, with which you may already be quite familiar, the material covered here should help you to understand the rest of the material in this book. It will also undoubtedly help in your pursuit of Juniper Networks career certifications.



Juniper Networks Reference Guide. JUNOS Routing, Configuration, and Architecture
Juniper Networks Reference Guide: JUNOS Routing, Configuration, and Architecture: JUNOS Routing, Configuration, and Architecture
ISBN: 0201775921
EAN: 2147483647
Year: 2002
Pages: 176

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net