1. Introduction
1.1 About the Cisco 1841 Integrated Services Router
The Cisco 1841 Integrated Services Router is designed for secure, wire-speed delivery of concurrent data, voice, and video services. This modular router integrates data and security features into a single, resilient system, ensuring fast and scalable delivery of critical business applications.
Key features of the Cisco 1841 router include:
- Modular Design: Allows for flexible network expansion and advanced application support.
- Embedded Hardware-Based Encryption: Enhances security, enabled by an optional Cisco IOS Software security image.
- VPN Performance Enhancement: Achieved with an optional VPN acceleration module.
- Integrated Real-Time Clock: Provides accurate timekeeping for network operations.

Figure 1: The Cisco CISCO1841 Integrated Services Router, showcasing its compact design and port layout.
2. Safety Information
Please read and understand all safety instructions before installing or operating the Cisco 1841 Integrated Services Router. Failure to follow these guidelines may result in injury or damage to the equipment.
- Electrical Safety: Connect the router only to a grounded power outlet. Do not operate the router with a damaged power cord.
- Ventilation: Ensure adequate airflow around the router to prevent overheating. Do not block ventilation openings.
- Handling: Handle the router with care. Avoid dropping or subjecting it to strong impacts.
- Environment: Operate the router in a clean, dry environment within the specified temperature and humidity ranges.
3. Package Contents
Verify that your package contains the following items. If any items are missing or damaged, contact your vendor.
- Cisco 1841 Integrated Services Router Unit
- Power Cable
- Quick Start Guide and other documentation
- Console Cable (may be included depending on vendor)

Figure 2: Included in the package are essential documents such as the Quick Start Guide and a console cable for initial configuration.
4. Setup Guide
4.1 Physical Installation
- Choose a Location: Select a stable, flat surface with adequate ventilation. Ensure the location is free from excessive dust, moisture, and extreme temperatures.
- Rack Mounting (Optional): If rack mounting, ensure you have the correct rack-mount ears for the Cisco 1841 model. Attach the ears to the router and secure it within a standard equipment rack.
- Connect Power: Connect the power cable to the router's power input and then to a grounded electrical outlet. Do not power on the device yet.

Figure 3: The Cisco CISCO1841 router is shown securely packaged with protective foam, illustrating its form factor before installation.
4.2 Initial Configuration
- Connect Console Cable: Connect one end of the console cable to the router's console port and the other end to a serial port on your computer.
- Establish Terminal Connection: Use a terminal emulation program (e.g., PuTTY, Tera Term) with the following settings: 9600 baud, 8 data bits, no parity, 1 stop bit, no flow control.
- Power On: Connect the power cable to the electrical outlet and power on the router. Observe the boot sequence in your terminal program.
- Basic Configuration: Follow the on-screen prompts to perform initial setup, including setting hostname, passwords, and basic interface configurations. Refer to the Cisco IOS Software documentation for detailed command-line interface (CLI) instructions.
- Cisco Security Device Manager (SDM): For graphical configuration, install and use Cisco SDM, if available for your IOS version. This tool assists in avoiding common misconfigurations.
5. Operation
5.1 Basic Network Functions
Once configured, the Cisco 1841 router facilitates network connectivity and traffic management.
- Connecting Devices: Connect your local area network (LAN) devices to the router's Ethernet ports. Connect your wide area network (WAN) connection (e.g., DSL, cable modem) to the appropriate WAN interface.
- Routing: The router will forward data packets between connected networks based on its routing table.
- Firewall: Utilize the integrated firewall features to protect your network from unauthorized access.
5.2 Advanced Features
- Virtual Private Network (VPN): Configure VPN tunnels for secure remote access or site-to-site connectivity, leveraging the router's encryption capabilities.
- Quality of Service (QoS): Implement QoS policies to prioritize critical network traffic, such as voice and video, ensuring optimal performance.
- Modular Expansion: Install various modules (e.g., WAN interface cards, voice modules) into the available slots to expand the router's functionality as needed.
6. Maintenance
6.1 Software Updates
Regularly updating the Cisco IOS Software is crucial for security and performance. However, please note that Cisco typically requires a maintenance contract to download software updates. Always back up your current configuration and IOS image before performing any updates.
6.2 Hardware Maintenance
- Cleaning: Periodically clean the router's exterior with a soft, dry cloth. Ensure ventilation openings are free from dust and debris.
- Fan Inspection: Check the cooling fan for proper operation. If the fan becomes noisy or fails, it may require replacement (e.g., a 60mmx60mmx15mm fan with a 3-pin connector).
- Internal Battery: The router contains an internal battery that may need replacement over time. Consult Cisco documentation for specific procedures.
7. Troubleshooting
This section provides general guidance for common issues. For detailed troubleshooting, refer to Cisco's official documentation and support resources.
7.1 Common Issues
- No Power: Ensure the power cable is securely connected and the power outlet is functional. Check the power supply unit.
- No Network Connectivity: Verify cable connections, check interface status (using CLI commands like `show ip interface brief`), and review IP addressing and routing configurations.
- Slow Performance: Check CPU utilization, memory usage, and interface errors. Review QoS policies if implemented.
- Configuration Errors: Incorrect configurations can lead to network issues. Use `show running-config` to review your current settings and `show startup-config` to see the saved configuration.
7.2 Support Resources
For advanced troubleshooting or technical assistance, visit the official Cisco support website or contact your authorized Cisco reseller.
8. Technical Specifications
| Feature | Specification |
|---|---|
| Product Dimensions | 10.8 x 13.5 x 1.73 inches |
| Item Weight | 6.1 pounds |
| Model Name | CISCO1841 |
| Manufacturer | Cisco |
| Connectivity Technology | Wired |
| Compatible Devices | Personal Computer |
| Recommended Uses | Security |
| Included Components | Fan |
| Date First Available | October 28, 2004 |
9. Warranty and Support
9.1 Manufacturer's Warranty
The Cisco 1841 Integrated Services Router is covered by a manufacturer's warranty. For specific warranty terms and conditions, please refer to the documentation provided with your product or visit the official Cisco website.
9.2 Customer Support
For technical support, product information, or service inquiries, please contact Cisco customer support through their official website or your authorized reseller. Ensure you have your product model and serial number available when seeking support.
9.3 Legal Disclaimer
Please be aware that certain vendors may apply specific terms regarding returns and restocking fees. For example, a 30% restocking fee may be charged to the buyer, and the buyer may be responsible for return shipping costs and ensuring returned items are insured. Always review the seller's return policy before purchase.





