Cisco 2691 Multiservice High-Performance Modular Access Router Full Product Description

1. Short Overview

Naming & Variant Breakdown

• C2691/K9: Standard AC-powered high-performance multiservice router with native K9 IPsec 3DES/AES crypto support
• C2691-DC/K9: 48V DC telecom-grade power variant for central office and industrial rack deployments
• C2691-RPS/K9: Variant supporting external redundant power supply systems for high-availability branch deployments
• -Vsuffix bundles: Pre-configured voice packages with AIM-VOICE DSP acceleration and Cisco CME/SRST licensing

Core Differentiators vs Cisco 2651XM

1. Dramatically higher forwarding throughput: Up to 70,000 pps mixed voice/data/security traffic vs 24,000 pps on the 2651XM (almost 2x performance gain)
2. Upgraded high-speed system bus optimized for high-density NM-HDV2 voice modules and high-bandwidth WIC DSL/T1/E1 cards
3. Expanded maximum memory ceiling: 256MB DRAM standard, expandable to 256MB; default Flash 32MB, max 48MB SIMM Flash
4. Optimized AIM slot supporting AIM-VPN/EP II high-performance encryption modules for high-volume multi-site VPN tunnels
5. Identical physical slot layout: 1 NM slot + 2 WIC slots + internal AIM daughtercard slot + dual Fast Ethernet LAN ports
6. Superior concurrent VoIP call capacity with NM-HDV2 DSP modules, supporting larger IP phone deployments via Cisco CallManager Express (CME)

2. Hardware Interface & Physical Specifications

Modular Expansion Architecture

1. 1 × NM (Network Module) slot: High-density universal slot cross-compatible with Cisco 2600, 3600, 3700 Series modules for voice, WAN, and terminal server deployments:
   • Dual T1/E1 PRI channelized trunk modules for PBX interconnection
   • NM-HDV / NM-HDV2 high-density DSP voice modules supporting up to 192 concurrent VoIP calls, T.38 fax relay, multi-party conferencing
   • ATM, Frame Relay, and 16-port analog modem terminal server modules for remote dial access
2. 2 × WIC (WAN Interface Card) slots: Interchangeable low-density WICs for primary broadband and redundant backup WAN links:
   • Synchronous/asynchronous serial leased lines, ISDN BRI
   • ADSL2+, G.SHDSL, VDSL2 copper broadband WICs (Annex A/M POTS, Annex B/J ISDN)
   • Dual-port serial and analog modem WICs for Dial-on-Demand Routing (DDR) failover
3. Internal AIM (Advanced Integration Module) daughtercard slot: Supports AIM-VPN/EP II encryption accelerators, AIM-VOICE DSP offload, AIM-ATM SAR processing, and AIM-COMPRESS data compression modules to offload CPU-intensive multi-service workloads without consuming external expansion slotsCisco.

Fixed Built-in Rear Panel Ports

1. 2 × 10/100BASE-TX autosensing Fast Ethernet LAN ports (RJ45)
   Auto-negotiates 10/100 Mbps full/half duplex; fully supports both Cisco ISL and IEEE 802.1Q VLAN trunking and inter-VLAN routing to isolate independent internal subnets (corporate staff, finance, guest Wi-Fi, POS payment networks).
2. RJ45 Console port (blue)– Local out-of-band CLI management, maximum baud rate 115.2 kbps
3. RJ45 AUX port (black)– Remote out-of-band management via external PSTN analog modem, asynchronous speed up to 115.2 kbps
4. Power inlet: Standard IEC AC socket (DC variant uses 48V terminal block telecom input)
5. Kensington anti-theft lock slot for physical rack chassis security

Memory & Performance Benchmarks

• Processor: Enhanced high-speed PowerQUICC RISC CPU optimized for multi-service voice, security, and VPN workloads
• DRAM: 3.3V SDRAM; factory default 256MB, maximum expandable to 256MB
• Flash memory: Single SIMM Flash slot; default 32MB, maximum supported Flash: 48MB 3.3V SIMM Flash
• Mixed voice/data packet forwarding throughput: Up to 70,000 packets per second (pps) under full multi-service load
• Hardware crypto acceleration: Onboard encryption engine + AIM-VPN/EP II module support for AES-256, 3DES, DES IPsec and SSL VPN offloading
• Maximum concurrent site-to-site IPsec tunnels: Up to 200+, scalable with DRAM and AIM crypto modules
• Supported IOS releases: Cisco IOS 12.2T, 12.3 mainline / 12.3T multiservice maintenance trains, fully compatible with advanced voice, security, carrier-grade feature sets unavailable on lower-tier 2600XM models
• Voice capacity: NM-HDV2 DSP modules support up to 192 concurrent VoIP calls, multi-party audio conferencing, T.38 real-time fax relay; Cisco CME supports up to 72 IP phones with SRST survivable remote site telephony

Physical & Power Parameters

• Form factor: 1U standard 19-inch rack-mount metal chassis with integrated rack ears
• Standard power supply: Internal universal AC power supply (100–240V 50/60Hz input; no external DC wall adapter required)
• DC variant (C2691-DC): 48V DC terminal block input for telecom central office racks
• Typical chassis power draw: ~65W under fully loaded NM/WIC/AIM module configuration
• Front panel status LEDs: System power, fault alarm, NM slot activity, two WIC slot link/activity, dual Fast Ethernet link/activity, AIM module health
• Operating environment: Dry indoor wiring closet / office deployments only
  • 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
• Dimensions (H × W × D): 4.3 × 44.5 × 30 cm (1.69 × 17.5 × 11.8 inches)
• Weight: ~4.9 kg (10.8 lbs) fully loaded with expansion modules
• No native chassis PoE output; IP cameras and wireless access points require external PoE injectors.

3. Cisco IOS Multiservice Full Feature Suite

Core Routing & Multi-WAN Connectivity

• Complete IPv4 routing stack: Static routes, RIP v1/v2, OSPF, EIGRP, BGP (IP Plus enterprise feature set)
• WAN encapsulation support: PPP, HDLC, Frame Relay, ATM, ISDN, PPPoE for DSL, Dial-on-Demand Routing (DDR) for redundant backup links
• HSRP/VRRP for router high availability failover; NHRP for DMVPN hub-spoke multi-site overlay VPN architectures
• NAT services: Static NAT, dynamic NAT, PAT overloading, NAT pool management for multi-user Internet access
• Dual VLAN trunking standards (ISL + IEEE 802.1Q) for inter-VLAN routing across dual onboard Fast Ethernet ports and downstream switches.

Multiservice Voice & Fax Integration (High-Density Voice Flagship Feature)

1. VoIP call control protocols: H.323, SIP, MGCP, SCCP native support for Cisco Unified IP Phone integration
2. Analog/digital telephony via NM-HDV2 DSP + VIC voice cards: FXS station ports, FXO PSTN trunk ports, E&M PBX tie-line support, T1/E1 PRI trunk interworking with third-party PBX vendors (Avaya, Siemens, Nortel)
3. T.38 real-time fax relay over IP, fax passthrough, store-and-forward fax routing
4. Voice compression codecs: G.711, G.729a, G.726 with hardware DSP acceleration to minimize WAN bandwidth consumption
5. Multi-site scalable dial plans, voice hunt groups, toll bypass to eliminate expensive long-distance PSTN charges
6. Cisco CME embedded call processing, SRST survivable remote telephony, Unity Express voice messaging via AIM storage modules

Enterprise QoS & Bandwidth Management

• Base QoS tools: Weighted Fair Queuing (WFQ), per-interface traffic shaping
• Advanced QoS (IP Plus image): Low Latency Queuing (LLQ), Frame Relay Traffic Shaping (FRTS), WRED congestion avoidance, DSCP/802.1p marking, Link Fragmentation and Interleaving (LFI) to eliminate voice jitter on low-speed WAN circuits
• cRTP VoIP header compression to reduce packet overhead on DSL and ISDN backup links.

Integrated Self-Defending Network Security

1. IOS Context-Based Access Control (CBAC) stateful zone-based firewall: Deep application-layer inspection for HTTP, FTP, SIP, H.323, and all mainstream enterprise business applications
2. Optional IOS signature-based inline IDS for real-time intrusion detection and automated threat mitigation
3. Hardware-accelerated VPN suite (with AIM-VPN/EP II module):
   • 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
   • L2TP/L2F remote worker user VPNs
4. AAA security framework: PAP/CHAP authentication, RADIUS/TACACS+ centralized access control and full audit logging
5. Standard/extended ACLs, dynamic ACLs, anti-DDoS traffic policing, and security zone segmentation to isolate sensitive payment and finance subnets.

Management & Operations

• Dual out-of-band management interfaces: RJ45 serial Console and AUX modem port for remote emergency access
• Secure remote management: SSHv2, HTTPS, SNMP v1/v2c with RMON traffic statistics collection
• Graphical configuration utility: Cisco Configuration Professional (CCP) for simplified zero-touch branch deployment
• AutoInstall automated remote configuration download over WAN links for mass branch rollouts
• Single Flash bank storage for IOS image hosting (no dual-bank redundant boot partition)
• Syslog persistent event logging, NTP time synchronization for consistent audit log timestamps.

4. Typical Deployment Scenarios

1. Large regional enterprise multi-service edge gateway: Dual fiber Metro Ethernet primary/secondary WAN uplinks, VDSL2 WIC copper backup, NM-HDV2 high-density DSP voice module supporting dozens of office IP phones and analog fax machines, dual Fast Ethernet ports to segregate finance, engineering, staff, and guest subnets, high-volume DMVPN IPsec tunnels to corporate headquarters, CBAC firewall for enterprise compliance.
2. Flagship multi-store retail voice gateway: T1 PRI NM leased-line primary voice trunk, ISDN BRI WIC dial backup, integrated firewall for PCI DSS payment security, CME embedded call processing for on-site store IP phones, USB modem/AUX port remote out-of-band maintenance for IT teams.
3. Global carrier managed high-capacity business CPE: Universal dual-standard DSL WIC copper broadband access, dual Fast Ethernet multi-segment enterprise LAN, AIM-VPN encryption module for mass customer VPN offloading, DMVPN overlay to carrier central service hub, integrated IDS/firewall for tenant threat protection.
4. Advanced networking training lab core router: Universal NM/WIC modularity to teach high-density T1/E1 PRI voice trunking, dual-standard ISL/802.1Q VLAN trunking, high-throughput IPsec VPN, and enterprise voice gateway labs; 256MB large DRAM fully supports full-featured IOS 12.3T images unavailable on all lower-tier 2600XM routers.

5. Standard Package Contents of C2691 / C2691-DC / C2691-RPS

Separately Sold Optional Accessories

• WAN Interface Cards (WIC-1B-S/T, WIC-T1-DSU, WIC-VDSL2, WIC-2SERIAL, etc.)
• Network Modules (NM-2T1, NM-HDV, NM-HDV2, NM-16AM analog modem terminal server, etc.)
• VIC voice interface cards for analog/digital telephony trunking
• AIM daughtercards: AIM-VPN/EP II encryption, AIM-VOICE DSP offload, AIM-ATM, AIM-COMPRESS data compression modules
• 3.3V SIMM Flash memory upgrades (32MB / 48MB)
• CAT5e/CAT6 Fast Ethernet patch cords, RJ11 DSL/ISDN telephone line cables
• External PoE injectors for IP cameras and wireless access points
• External redundant power supply units (RPS-compatible variants)

Software Licensing Information

Short Commercial Catalog Summary