Cisco 1941 ISR G2 Full Product Description

1. Short Overview

Suffix & Variant Breakdown

• C1941/K9: Base wired modular router with permanent K9 crypto licensing
• C1941W-A/K9,C1941W-E/K9: Wireless variants with integrated 802.11a/b/g/n Wi-Fi AP
• C1941DC/K9: 48V DC power input variant for telecom rack and industrial deployments
• -SEC: Pre-activated security license bundle

Core Differentiators vs Cisco 1921

1. Dedicated 1 × ISM (Internal Services Module) slot (absent on 1921) for virtualized application hosting, storage, or advanced security servicesCisco
2. Dual independent CompactFlash slots (slot0 + slot1) for redundant IOS image and config storage (1921 has only one CF slot)Cisco
3. Higher multi-service throughput: Up to 45 Mbps mixed voice/data/security vs 15 Mbps on the 1921Cisco
4. Larger maximum memory: 2GB ECC DRAM / 4GB per CF slot (1921 max 2GB DRAM / 2GB single CF)Cisco
5. Optional factory-integrated 802.11n dual-band wireless AP variants (no wireless option for base 1921)Cisco
6. Dual EHWIC slots support double-wide EHWIC-D modules; ISM slot adds extensible service virtualization
7. Identical dual Gigabit Ethernet ports, dual USB 2.0 ports, and dual console access as the 1921

2. Hardware Interface & Performance Specifications

Modular Expansion Architecture

1. 2 × EHWIC (Enhanced High-Speed WAN Interface Card) slots: Accept two single-wide EHWIC/HWIC/WIC/VWIC cards or one double-wide EHWIC-D module, fully backward compatible with ISR 1800 Series modules:
   • Serial synchronous/asynchronous, T1/E1/FT1 integrated DSU/CSU
   • ADSL2+, VDSL2, G.SHDSL broadband DSL WANs
   • ISDN BRI, analog modem WICs for dial backup
   • 4-port Fast Ethernet switch HWICs for extended LAN segmentation
   • Voice VWICs for analog/digital trunk telephony (requires separate PVDM DSP modules for VoIP/fax)
2. 1 × ISM (Internal Services Module) slot (wired C1941 only; removed on 1941W wireless models): Hosts service modules for virtualized applications, centralized storage, or advanced security processing (e.g., ISM-160GB storage modules, application hosting blades)Cisco
3. No internal AIM crypto slots; AES-256/3DES IPsec acceleration is fully integrated on the motherboard

Fixed Built-in Physical Ports (Rear Panel)

1. 2 × Auto-MDI-X 10/100/1000BASE-T Gigabit Ethernet (GE0/0, GE0/1)
   Auto-negotiates 10/100/1000 Mbps full/half duplex, supports IEEE 802.1Q VLAN trunking, inter-VLAN routing, and LACP link aggregation for redundant primary/secondary LAN/WAN uplinks
2. Dual Console Access:
   • RJ45 serial console port (115.2 kbps max baud rate)
   • Mini Type-B USB 2.0 console port for direct PC out-of-band management without rollover cables
3. RJ45 AUX port: Remote out-of-band management via external analog PSTN modem
4. 2 × USB 2.0 Type-A host ports: For external CAT4/CAT6 USB LTE cellular dongles (third independent wireless failover), USB flash storage for offline config/log archiving, or authentication tokens
5. Power inlet: Standard IEC AC socket (DC variant uses terminal block 48V DC input)
6. Kensington anti-theft lock slot for physical rack chassis security

Integrated Wireless Subsystem (1941W Variants Only)

• Internal dual-band 802.11a/b/g/n concurrent Wi-Fi radio (2.4 GHz + 5 GHz)
• Two RP-TNC external antenna jacks for high-gain antenna extension
• Supports multiple SSID segmentation, WPA2-Enterprise, wireless QoS (WMM), rogue AP detection, and wireless VLAN mapping

Memory & Performance Benchmarks

• DRAM: ECC DDR2 memory; default 512MB, maximum expandable to 2GBCisco
• Flash: Dual CompactFlash slots (Slot0 + Slot1); default Slot0: 256MB, max 4GB per slotCisco
• Multi-service throughput: Up to 45 Mbps under full mixed voice/data/security workloadsCisco
• Onboard dedicated hardware crypto accelerator: Native AES-256, 3DES, DES IPsec and SSL VPN offloading
• Maximum concurrent site-to-site IPsec tunnels: 200+, scalable with DRAM upgrades
• Supported IOS releases: Cisco IOS 15.x Universal images; feature sets (IP Base, Security, Unified Communications, Data) activated via permanent software license keys
• Voice capacity: Compatible with PVDM2/PVDM3 DSP modules on VWIC slots for VoIP, T.38 fax relay, and multi-party voice conferencing

Physical & Power Parameters

• Form factor: 1U standard 19-inch rack-mount metal chassis with integrated rack ears
• Internal high-efficiency universal AC power supply (100–240V 50/60Hz); DC variant supports 48V telecom-grade DC input
• Max chassis power draw: 130W (AC model)
• Front panel LEDs: System power, fault alarm, dual GE link/activity, EHWIC slot status, ISM module health, USB activity, Wi-Fi radio (W variants), VPN crypto engine status
• Operating environment: Indoor wiring closet / office deployments
  • Operating temperature: 0°C to +40°C below 1800m altitude; 0°C to +25°C above 1800m up to 3000m
  • Relative humidity: 10–85% RH non-condensing
• Acoustic noise: Typical 34 dBA, max 59 dBA under full load
• No native chassis PoE output; PoE-capable EHWIC modules deliver IEEE 802.3af inline power to connected endpoints

3. Cisco IOS Universal Image Feature Suite

Core Routing & Multi-WAN Connectivity

• Full IPv4 routing stack: Static routes, RIP v1/v2, OSPF, EIGRP, BGP
• WAN encapsulations: PPP, HDLC, Frame Relay, PPPoE, PPPoA, ISDN, Dial-on-Demand Routing (DDR) for redundant backup links
• HSRP/VRRP for router failover redundancy; NHRP DMVPN hub-spoke multi-site overlay VPN architectures
• NAT services: Static NAT, dynamic NAT, PAT overloading, NAT64 for IPv4-IPv6 transition
• IEEE 802.1Q VLAN trunking, inter-VLAN routing, LACP Ethernet link aggregation, storm control

Unified Communications & VoIP Features

• Voice call control protocols: H.323, SIP, MGCP, SCCP (Cisco Unified IP Phone integration)
• Analog/digital telephony via VWIC + PVDM DSP modules: FXS/FXO/E&M trunk and station line support
• T.38 real-time fax relay, fax passthrough, G.711/G.729a/G.726 voice compression, built-in echo cancellation
• Multi-site dial plans, voice hunt groups, toll bypass to reduce long-distance PSTN telephony costs, video over IP support

Enterprise QoS & WAN Optimization

• Full layered QoS toolkit: Low Latency Queuing (LLQ), CBWFQ, WFQ, WRED, DSCP/802.1p traffic marking
• Link Fragmentation and Interleaving (LFI), cRTP VoIP header compression for low-speed backup WAN links
• WAN traffic shaping for Frame Relay, DSL, and Metro Ethernet; bandwidth policing for guest/non-business traffic
• NBAR2 next-generation deep packet inspection for application-aware QoS prioritization of business-critical apps

Integrated Self-Defending Network Security

1. Zone-Based Firewall (ZBFW): Stateful application-layer deep inspection for HTTP, FTP, SIP, H.323, and other business protocols
2. Embedded IOS IPS signature-based inline intrusion prevention and real-time threat mitigation
3. Hardware-accelerated VPN suite:
   • AES-256/3DES/DES IPsec site-to-site branch tunnels
   • Cisco Easy VPN Remote for centralized security policy push to remote branch locations
   • DMVPN 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/wireless port authentication, Network Admission Control (NAC) endpoint compliance
5. URL filtering, dynamic ACLs, anti-DDoS traffic policing, security zone segmentation to isolate sensitive subnets (e.g., POS payment VLANs)

Wireless LAN Features (1941W Only)

• Concurrent dual-band 802.11a/b/g/n AP operation
• Multiple SSID segmentation with separate VLAN mapping for staff, guest, and IoT wireless clients
• WPA2-Enterprise/Personal encryption, 802.1X EAP authentication
• Rogue wireless AP detection and containment
• WMM wireless QoS for voice/video over Wi-Fi
• Wireless client isolation to block peer-to-peer traffic between wireless endpoints

Management, Automation & Operations

• Dual console management: RJ45 serial + mini USB Type-B console port
• Secure remote access: SSHv2, HTTPS, SNMP v3 (backward compatible with SNMP v1/v2c)
• Web-based Cisco Configuration Professional (CCP) graphical GUI for simplified zero-touch provisioning and security policy management
• Syslog event logging, NTP time synchronization for consistent audit log timestamps, RMON traffic statistics collection
• AutoInstall remote configuration download over WAN links
• Dual Flash bank storage for primary and backup IOS image disaster recovery (unique to 1941 series)
• USB mass storage support for offline configuration archives and persistent logging
• EnergyWise intelligent power monitoring and idle module power reduction to cut energy consumption

4. Typical Deployment Scenarios

1. Regional medium enterprise multi-service edge router: Dual Gigabit Ethernet primary/secondary Metro Ethernet uplinks, T1 EHWIC leased-line tertiary backup, ISM storage module for local config/log archiving, PVDM DSP modules for dozens of office VoIP phones, ZBFW firewall + IPsec DMVPN tunnel to corporate headquarters, multi-VLAN segmentation for finance, HR, engineering, and guest subnets
2. Global DSL/G.FAST carrier managed high-capacity business CPE: VDSL2 EHWIC copper broadband access, dual GE ports for multi-segment enterprise LAN, ISM security module for advanced threat analytics, integrated security suite for customer compliance, DMVPN overlay to carrier central service hub
3. Large retail flagship rack router: PoE-capable EHWIC switch module powering dozens of POS security cameras and multi-line IP phones, dual redundant fiber WAN uplinks, universal DSL backup, USB LTE dongle fourth-layer wireless failover, 1941W wireless variant for multi-floor guest/employee Wi-Fi segmentation
4. Multi-building campus central aggregation router: 12-port PoE EHWIC for distributed building surveillance cameras and intercoms, dual combo fiber WAN primary/secondary backhaul to campus core network, ISDN/POTS DSL copper backup, ISM virtualized service hosting for local campus IoT management
5. Remote industrial M2M central wiring closet router: Serial EHWIC for leased-line SCADA connectivity, DC power variant for telecom cabinet deployment, AUX-port modem out-of-band management, encrypted IPsec tunnels for secure industrial data transmission, optional wireless AP for on-site technician BYOD access

5. Standard Package Contents of C1941 / C1941W

Separately Sold Optional Accessories

• EHWIC/HWIC/WIC/VWIC WAN and switch interface cards
• PVDM2/PVDM3 DSP voice compression modules for VoIP/fax relay
• ISM service/storage modules (compatible with wired C1941 only)
• PoE-enabled EHWIC modules for inline 802.3af/ePoE power delivery
• CompactFlash memory upgrades (512MB / 1GB / 4GB for dual CF slots)
• CAT5e/CAT6 Gigabit Ethernet patch cords, RJ11 DSL/ISDN telephone line cables
• CAT4/CAT6 USB LTE cellular dongles for auxiliary wireless backup WAN
• USB flash storage drives for offline configuration and log archiving
• High-gain external Wi-Fi antennas (for 1941W wireless variants)
• External PoE injectors for non-PoE endpoint devices

Software Licensing Information

Short Commercial Catalog Summary