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How to select your core routers?

This question comes to my mind every time we are faced by choosing a new device for our network or whenever I read about hardware architecture of networking devices. However, when the time comes for  choosing routers for a large network migration I thought it will be wise to have a checklist or a model for comparing and evaluating the different options. I came out with the following list to start with, read it and let me know us your ideas. My Core routers evaluation checklist: Packet forwarding capacity: The main function of routers in the core network is to …

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CRS-1 Hardware Overview

After introducing the Cisco  CRS-1 router in a previous post, We are going to delve more into the hardware architecture of this router. I believe we have to start by defining the main hardware components of the CRS-1 router and briefly describe their functions. In later posts we are going to study each part in more details. Now lets continue our baby steps. Note: I will be focusing on single chassis configurations.

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Carrier Routing System (CRS-1) Overview

We have finished the physical installation of our CRS-1 routers this week, so I thought it would be nice to have some discussions about CRS-1, Juniper T-series and some general high end platform concepts. I believe this will be a series of posts, we can start with the CRS-1 overview. The CRS-1 is a carrier class router as its name implies, it comes in 4, 8  and 16 slots chassis. The system can be configured as a single or multi-shelf system (Currently only 16 slots supports multi-shelf configuration).

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Routers’ Operating systems

The router operating system is a piece of software responsible for managing the router resources by controlling and allocating memory, prioritizing system requests and processes, controlling I/O devices and managing file systems. The most two famous router operating systems are Cisco IOS and Juniper JUNOS. Cisco IOS is a monolithic OS which means it runs as a single operation with all processes sharing the same memory space. This means a bug in o­ne process can impact or corrupt other processes also means that adding new features to the OS requires upgrading the full IOS image itself. JUNOS is a modular …

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Routers’ Memory types

The memory come in many forms for several storage purposes such as to store the operating system , the configuration, the bootstrap, packets, and so forth. Below is a detailed description of all memory types used in routers and the purpose of each. BootROM BootROM is used for permanently the storage of the startup diagnostic code (ROM Monitor). The main task for the BootROM is to perform some hardware diagnostics during bootup on the router, Power On Self Test (POST), and to load the Cisco IOS software from the Flash to the Memory. Flash Flash memory is a non-volatile memory …

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