The **CRS-A16-R** is a high-performance, chassis-based router component, specifically a **Fabric Card** (or Switch Fabric) designed for the Cisco Carrier Routing System (CRS). It acts as the "brain" of the switching architecture, ensuring data packets are moved efficiently between different line cards. --- ### 1. Key Electronic Components and Specifications The electronic architecture of the CRS-A16-R is centered around high-speed ASIC (Application-Specific Integrated Circuit) technology and high-density interconnects. | Component Category | Description | | :--- | :--- | | **ASIC Type** | Uses custom Cisco Silicon (S13/S2/S3) for cell-based switching. | | **Throughput** | Supports up to 400 Gbps to 1.2 Tbps per slot depending on the chassis generation. | | **Memory** | Integrated high-speed SRAM/DRAM for packet buffering and lookup tables. | | **Interface** | High-density backplane connectors for integration with the 16-slot chassis. | | **Power Consumption** | Approximately 275W to 350W depending on traffic load. | --- ### 2. Functional Electronic Blocks The CRS-A16-R functions through several specialized electronic subsystems: #### A. Switch Fabric ASICs The heart of the card consists of fabric ASICs that implement a **multi-stage Benes architecture**. Instead of switching whole packets, the electronics break data into fixed-size "cells." This prevents head-of-line blocking and ensures low latency. #### B. Power Management Circuitry Because the card resides in a carrier-grade chassis, it features: * **DC-to-DC Converters:** To step down the chassis backplane voltage to the low voltages required by high-speed chips. * **Hot-Swap Controllers:** Allows the card to be inserted or removed without powering down the entire system. #### C. Thermal Sensors and Management The card includes multiple embedded thermal sensors that communicate with the chassis's fan control system via the I2C bus to manage heat dissipation across the dense silicon arrays. --- ### 3. Comparison of CRS Fabric Generations The "R" in CRS-A16-R often denotes a specific revision or performance tier within the CRS-1 or CRS-3 lineage. | Feature | CRS-1 (Standard) | CRS-A16-R (Enhanced/Refurb) | | :--- | :--- | :--- | | **Slot Bandwidth** | 40 Gbps | Up to 140+ Gbps | | **Efficiency** | Standard | Improved Power-per-Watt | | **Compatibility** | CRS-1 Chassis | CRS-1 and CRS-3 (Multigenerational) | --- ### Summary of Physical Characteristics * **Form Factor:** Vertical blade for 16-slot chassis. * **LED Indicators:** Status LEDs for Power, Alarms, and Fabric Load. * **Connectivity:** Blind-mate connectors on the rear for the midplane.