Cisco 1841 Integrated Services Router Full Product Description

1. Short Overview

Naming & Key Variants

• 1841: Base modular data ISR (no native voice DSP support, VWICs only usable for data)
• -K9: IOS Advanced IP Services crypto image with AES/3DES IPsec encryption
• No dedicated-Vvoice variant; this model lacks PVDM DSP slots and cannot run full VoIP telephony gateways

Core Differentiators vs Cisco 1751 / 1760

1. Over 5x faster packet forwarding throughput vs 1700 Series routers
2. Dual HWIC slots (higher-speed WAN expansion) + backward compatibility with 30+ legacy 1700 WIC/VWIC data cards
3. 1U rack-mount chassis with internal AC power supply (17xx desktop models use external DC adapters)
4. Larger maximum memory ceiling: 384MB DRAM / 128MB Flash vs 96MB DRAM / 64MB Flash on top 1700 models
5. Built-in hardware crypto engine on motherboard (optional AIM-VPN module for further VPN offloading)
6. No voice DSP/PVDM slots – strictly data routing (1751/1760 support VIC voice cards and DSP modules)
7. Two onboard Fast Ethernet ports vs single FE port on all 1700 routers

2. Hardware Interface & Performance Specifications

Modular Expansion Architecture

1. 2 × HWIC (High-Speed WAN Interface Card) slots: Support new-generation high-speed WAN modules, and are backward-compatible with all 1700-series WICs/VWICs (data-only use for VWICs). Supported HWIC/WIC types:
   • Serial synchronous/asynchronous, T1/E1/FT1 integrated DSU/CSU
   • ADSL, G.SHDSL, VDSL, G.FAST broadband DSL
   • ISDN BRI, analog modem WICs for dial backup
   • 4-port Fast Ethernet switch HWICs for extended LAN switching
2. 1 × AIM (Advanced Integration Module) internal slot: Accepts AIM-VPN/SSL-2 encryption accelerator modules to offload high-volume IPsec/SSL VPN traffic beyond the onboard crypto engine
3. No PVDM/DSP voice expansion slots – voice telephony workloads are not supported on the C1841 chassis

Fixed Built-in Ports (Rear Panel)

1. 2 × 10/100BASE-TX autosensing Fast Ethernet LAN ports (RJ45)
   Auto-negotiates 10/100 Mbps full/half duplex, supports IEEE 802.1Q VLAN trunking and inter-VLAN routing for multi-segment office LANs
2. RJ45 Console port (blue)– Local out-of-band CLI management, max 115.2 kbps baud rate
3. RJ45 AUX port (black)– Remote out-of-band management via external analog PSTN modem
4. 1 × USB 2.0 Type-A port– For USB flash storage (config/log archiving), USB LTE dongle auxiliary wireless backup
5. Internal universal AC power inlet (100–240V 50/60Hz, built-in power supply, no external DC adapter required)
6. Kensington security lock slot for physical rack anti-theft protection

Memory & Performance Benchmarks

• Default DRAM: 128MB; maximum expandable DRAM: 384MB SDRAM
• Default Flash memory: 32MB; maximum supported Flash: 128MB external compact Flash (dual-bank for primary/backup IOS images)
• Packet forwarding throughput: Up to 100,000 packets per second (pps)
• Onboard integrated hardware crypto accelerator: Native AES, 3DES, DES encryption support; AIM-VPN modules boost concurrent VPN tunnel capacity
• Maximum concurrent IPsec site-to-site VPN tunnels: Up to 200 (scales with DRAM and AIM crypto module)
• Supported IOS releases: Cisco IOS 12.4T, 15.0M Advanced IP Services K9 images; preloaded Cisco SDM web GUI for simplified deployment
• No native voice conference or fax relay support due to absent DSP hardware

Physical & Power Parameters

• Form factor: 1U standard 19-inch rack-mount metal chassis (integrated rack ears included)
• Internal universal AC power supply (100–240V 50/60Hz input, IEC power cord included)
• Front panel LEDs: System power, HWIC slot link/activity, dual Fast Ethernet port status, crypto module health, USB activity
• Operating environment: Dry indoor wiring closet use only; operating temperature range 0°C to +40°C, non-condensing relative humidity 10–85% RH
• Noise level: 34–42 dBA fan-cooled chassis (low-noise fan for rack deployments)
• No native PoE power output; all IP cameras, wireless APs, and PoE endpoints require external PoE injectors

3. Cisco IOS Advanced IP Services Feature Suite

Core Routing & WAN Connectivity

• IPv4 routing protocols: Static routes, RIP v1/v2, OSPF, EIGRP, BGP (Advanced IP Services image)
• WAN encapsulations: PPP, HDLC, Frame Relay, ISDN, PPPoE for DSL broadband, Dial-on-Demand Routing (DDR) for redundant backup links
• HSRP for router failover redundancy; NHRP for DMVPN hub-spoke multi-site overlay VPN architectures
• Network Address Translation (NAT): Static NAT, dynamic NAT, PAT overloading for multi-user Internet access
• IEEE 802.1Q VLAN trunking and inter-VLAN routing; LACP for Ethernet link aggregation

QoS & Bandwidth Management

• Full enterprise QoS toolkit: Low Latency Queuing (LLQ), CBWFQ, WFQ, WRED, DiffServ DSCP marking, Link Fragmentation and Interleaving (LFI)
• Traffic shaping for Frame Relay, DSL, and Metro Ethernet WAN links; cRTP header compression for low-speed backup circuits
• QoS classification based on source/destination IP, port numbers, DSCP tags, and application signatures

Integrated Self-Defending Network Security

1. Stateful Context-Based Access Control (CBAC) firewall: Deep application-layer inspection for HTTP, FTP, SIP, H.323, and other business protocols
2. Embedded inline Intrusion Prevention System (IPS): Signature-based threat detection and real-time traffic mitigation
3. Hardware-accelerated VPN stack (onboard + AIM offload):
   • IPsec site-to-site tunnels with AES/3DES/DES encryption
   • Cisco Easy VPN Remote for centralized security policy push to remote branch locations
   • DMVPN for scalable hub-spoke multi-site overlay networks
   • SSL VPN for browser-based remote worker access without client software
4. AAA security framework: RADIUS/TACACS+, PAP/CHAP, 802.1X wired port authentication, Network Admission Control (NAC) endpoint compliance
5. Standard/extended ACLs, dynamic ACLs, URL filtering, and traffic policing for granular threat containment

Management & Operations

• CLI command-line management via Console/AUX ports or SSH v2 remote access
• Web-based Cisco SDM graphical GUI for zero-touch simplified provisioning and security policy management
• SNMP v1/v2c for network monitoring, RMON traffic statistics collection, syslog event logging, NTP time synchronization for audit log consistency
• AutoInstall: Automated remote configuration download over WAN links
• Dual Flash bank storage for primary and backup IOS image disaster recovery
• USB mass storage support for offline configuration archives and persistent logging

4. Typical Deployment Scenarios

1. Regional medium enterprise rack edge router: Dual T1 HWIC redundant leased-line primary/secondary WANs, ADSL WIC dial backup, inter-VLAN routing for finance, HR, and engineering office subnets, hardware VPN acceleration for dozens of concurrent site-to-site IPsec tunnels to corporate headquarters
2. Global DSL/G.FAST carrier managed CPE: G.SHDSL HWIC copper broadband access, dual Fast Ethernet ports for multi-segment enterprise LAN, integrated stateful firewall and IPS for customer threat protection, DMVPN overlay to carrier central hub
3. Networking training lab core router: Flexible HWIC/WIC modularity for teaching serial, T1, DSL, ISDN WAN connectivity, multi-VLAN routing, IPsec VPN, and IOS security labs; cross-compatible with legacy 1700-series WIC training inventory
4. Multi-building campus central data aggregation router: Dual fiber media-converter FE uplinks for primary/secondary campus core backhaul, serial HWICs for remote building SCADA M2M connectivity, NAT for multi-subnet Internet sharing

5. Standard Package Contents of C1841

Separately Sold Optional Accessories

• HWIC high-speed WAN interface cards (HWIC-1T, HWIC-T1-DSU, HWIC-ADSL, HWIC-4ESW, etc.)
• Legacy WIC/VWIC data cards from Cisco 1700 Series
• AIM-VPN/SSL-2 encryption accelerator module for high-volume VPN offloading
• CAT5e/CAT6 Ethernet patch cords, RJ11 DSL/ISDN telephone line cables
• CAT4/CAT6 USB LTE cellular dongles for auxiliary wireless backup WAN
• Compact Flash memory cards (32MB / 64MB / 128MB) for IOS image expansion
• USB flash storage drives for offline configuration and log archiving
• External PoE injectors for IP cameras and wireless access points

Software Licensing Information

Short Commercial Catalog Summary