Cisco 2951 Integrated Services Router (ISR Generation 2) Full Product Description

1. Short Overview

Naming & Variant Breakdown

• CISCO2951/K9: Standard AC-powered flagship router with universal IOS image and embedded K9 crypto hardware
• CISCO2951-SEC/K9: Pre-bundled Security license variant with Zone-Based Firewall, IOS IPS, full DMVPN/IPsec/SSL VPN enabled
• CISCO2951-V/K9: Unified Communications bundle pre-licensed for CME/SRST embedded voice call processing
• CISCO2951-VSEC/K9: All-in-one integrated Voice + Security branch bundle
• CISCO2951-AX/K9: Advanced services bundle supporting SRE virtualization, WAAS wide-area optimization
• CISCO2951-AC-IP/K9: AC PoE power supply variant with high-wattage inline power for IP phones via switch EHWICs
• CISCO2951-DC/K9: 24–60V negative DC autoranging telecom-grade power model for central office cabinet deployments
• -HSEC+/K9: High-security enhanced bundle optimized for hundreds of concurrent IPsec tunnels; FIPS 140-2 Level 2 compliant with optional FIPS shield kit
• -RPS: Variant compatible with external redundant power supply systems for mission-critical high-availability branches

Core Differentiators vs Cisco 2921

1. Dual independent DRAM DIMM slots (2921 has one soldered base DRAM slot) supporting asymmetric memory configurations up to 2GB total
2. Dual separate CompactFlash storage slots (Slot0 + Slot1, max 4GB per slot, total 8GB) – single CF slot on 2921 for IOS image redundancy and separate log/app storage
3. Higher aggregate multi-service throughput up to 170 Mbps vs 130 Mbps on the 2921 for heavy mixed voice/security/VPN workloads
4. Larger maximum chassis power budget (340W fully loaded) supporting full complement of high-power EHWIC, triple PVDM3, and SRE ISM modulesCisco
5. Identical core expansion layout: 4 universal EHWIC slots, 1 ISM internal service module slot, 3 motherboard PVDM3 DSP slots, 3 Gigabit RJ45 + shared SFP fiber port, dual USB 2.0, dual console ports, native RPS support, DC power option
6. Same multi-core PowerQUICC CPU architecture, triple PVDM3 DSP capacity, shared SFP fiber uplink, triple out-of-band management interfaces

2. Hardware Interface & Physical Specifications

Modular Expansion Architecture

1. 4 × Rear Universal EHWIC (Enhanced High-Speed WAN Interface Card) slots
   Each slot accepts single-wide EHWIC, double-wide EHWIC-D, legacy HWIC, WIC, analog VIC, multi-flex VWIC voice cards; two slots support double-wide high-bandwidth EHWIC-D modules:
   • EHWIC: ADSL2+, VDSL2, G.SHDSL, synchronous serial, 4-port GE switch, cellular 3G/4G wireless WAN cards
   • WIC: ISDN BRI, synchronous/asynchronous serial, analog modem WICs for Dial-on-Demand Routing (DDR) backup failover
   • VIC/VWIC: FXS/FXO/E&M analog station/trunk cards, fractional T1/E1 multi-flex voice trunks, multi-port PRI channelized trunk modules
2. 1 × ISM (Internal Service Module) internal slot
   Replaces ISR 1-generation AIM slots; supports SRE (Services Ready Engine) virtualization modules, WAAS wide-area bandwidth optimization, ISM-CUE voice mail storage, and embedded application services to offload CPU-intensive tasks without occupying external EHWIC slots.
3. 3 × Motherboard PVDM3 DSP slots
   Host Packet Voice Digital Signal Processor modules to handle VoIP codecs, wideband G.722 audio, G.168 echo cancellation, T.38 fax relay, and multi-party audio conferencing without consuming external expansion slots; triple DSP capacity enables large-scale IP phone deployments up to 200+ endpoints.

Fixed Built-in Rear Panel Ports

1. 3 × Auto-MDI-X 10/100/1000BASE-T Gigabit Ethernet (GE0/0, GE0/1, GE0/2) + 1 shared SFP mini-GBIC fiber slot
   The SFP port shares hardware with GE0/0; activating the SFP disables the corresponding RJ45 port. All Gigabit ports fully support IEEE 802.1Q VLAN trunking, inter-VLAN routing, LACP link aggregation to isolate corporate, finance, engineering, guest, and sensitive POS payment subnets.
2. RJ45 Serial Console port (115.2 kbps max baud) – primary local out-of-band CLI management
3. Mini-USB Type-B Console port – lightweight secondary local management without RJ45 cables
4. RJ45 AUX port – remote emergency access via external PSTN analog modem
5. 2 × USB 2.0 Type-A ports– high-speed offline config/log backup storage, two-factor crypto authentication tokens
6. Dual removable external CompactFlash slots (CF0 + CF1) – independent persistent storage for IOS universal images, running configurations, persistent event logging, and ISM application data
7. Power inlet: Standard IEC AC socket (DC variant uses 24–60V negative terminal block telecom input)
8. Dedicated RPS redundant power supply connector for fault-tolerant mission-critical branch deployments
9. Chassis ground lug + Kensington anti-theft lock slot for physical rack security

Memory & Performance Benchmarks

• Processor: Multi-core PowerQUICC RISC CPU with dedicated embedded hardware crypto FPGA acceleration
• DRAM: 3.3V ECC SDRAM; factory default 512MB split across dual DIMM slots, maximum expandable to 2048MB (2GB) with asymmetric DIMM combinationsCisco
• Flash memory: Dual independent CompactFlash slots; default CF0: 32MB, maximum supported Flash per slot: 4GB, total aggregate CF capacity up to 8GBCisco
• Multi-service mixed voice/data/security throughput: Up to 170 Mbps aggregate wire-speed performance, highest among all 2900 series routers
• Hardware crypto acceleration: Native AES-256, 3DES, DES IPsec, SSL/TLS, GRE VPN offloading; compatible with high-density SRE security modules for massive concurrent site-to-site tunnels
• Maximum concurrent site-to-site IPsec tunnels: Up to 350+, scalable with full 2GB DRAM and ISM security virtualization modules
• Supported IOS releases: Cisco IOS 15.0(1)M through 15.7(3)M universal multi-service maintenance images; feature functions unlocked via permanent chassis-bound software licenses (SL-29-DATA-K9, SL-29-SEC-K9, SL-29-UC-K9)
• Voice capacity: PVDM3 DSP modules support up to 144 concurrent VoIP calls, multi-party conferencing, T.38 fax relay; Cisco CME embedded call processing for up to 200 IP phones, SRST survivable remote branch telephony, Unity Express voice mail hosted via ISM-CUE storage modules

Physical & Power Parameters

• Form factor: 2U standard 19-inch rack-mount metal chassis with integrated rack ears
• Standard AC power supply: 100–240V 50/60Hz universal autoranging internal power supply (hot-swappable with external RPS support)
• DC variant (C2951-DC): 24–60V autoranging negative DC telecom input for central office cabinet deployments
• PoE variant (C2951-AC-IP): Integrated inline power distribution delivering up to 200W PoE budget, expandable to 750W with PoE boost accessory
• Maximum chassis power draw: 340W under fully loaded EHWIC/PVDM3/ISM module configurationCisco
• Front panel status LEDs: System power, fault alarm, dual CompactFlash activity, dual USB port status, PVDM/ISM health indicators, four EHWIC slot link/activity, three Gigabit Ethernet + SFP link/activity
• Operating environment
  • Operating temperature: 0°C to +40°C below 1800m altitude; 0°C to +25°C above 1800m up to 3000m
  • Relative humidity: 5–85% RH non-condensing
• Dimensions (H × W × D): 88.9 × 438.2 × 469.9 mm (3.5 × 17.25 × 18.5 inches)Cisco
• Weight: 13.2 kg empty chassis, up to 15.5 kg fully loaded with all expansion modulesCisco
• No native chassis PoE output except for dedicated -AC-IP power supply variant.

3. Cisco IOS Universal Image Multiservice Feature Suite

Core Routing & Multi-WAN Connectivity

• Full dual-stack IPv4 / IPv6 routing suite: Static routes, RIP v1/v2, OSPF, EIGRP, BGP, IS-IS, PIM multicast suite, BFD bidirectional forwarding detection
• WAN encapsulation support: PPP, HDLC, Frame Relay, ATM, ISDN, PPPoE/PPPoA for DSL, Dial-on-Demand Routing (DDR) for automatic backup failover, MPLS L2/L3 VPN, GETVPN
• HSRP/VRRP for router high availability redundancy; NHRP DMVPN hub-spoke multi-site overlay VPN architecture
• NAT services: Static NAT, dynamic NAT, PAT overloading, multi-address NAT pools, NAT64 IPv4-IPv6 transition support
• Dual VLAN trunking standards support: IEEE 802.1Q for inter-VLAN routing across three onboard Gigabit Ethernet ports and shared SFP fiber uplinks.

Unified Communications Voice & Fax Integration (Flagship High-Density Voice Differentiator)

1. VoIP signaling protocols: H.323, SIP, MGCP, SCCP native support for large-scale Cisco Unified IP Phone deployments
2. Analog/digital telephony via VIC/VWIC + triple PVDM3 DSPs: FXS station ports, FXO PSTN trunk lines, E&M PBX tie connections, fractional T1/E1 multi-flex voice trunks, multi-port PRI channelized trunk interworking with third-party PBX platforms
3. T.38 real-time fax relay over IP, fax passthrough, store-and-forward fax routing
4. DSP-accelerated voice codecs: G.711, G.729a, G.726, wideband G.722 high-fidelity audio, video conferencing codec support
5. Enterprise telephony tools: Scalable multi-site dial plans, voice hunt groups, toll bypass to eliminate expensive long-distance PSTN charges
6. CME embedded call manager, SRST survivable remote telephony, Unity Express voice mail/auto-attendant hosted via ISM-CUE storage modules.

Enterprise QoS & WAN Optimization

• Base QoS tools: Weighted Fair Queuing (WFQ), CBWFQ, per-interface traffic shaping
• Advanced QoS (Data/UC license): Low Latency Queuing (LLQ), Frame Relay Traffic Shaping (FRTS), WRED congestion avoidance, DSCP/802.1p traffic marking
• Link Fragmentation and Interleaving (LFI), cRTP VoIP header compression to eliminate voice jitter over low-speed DSL/ISDN backup links
• NBAR2 next-generation deep packet inspection for application-aware traffic prioritization of business-critical software; ISM WAAS module for end-to-end WAN bandwidth optimization and deduplication.

Integrated Self-Defending Network Security Suite

1. Zone-Based Stateful Firewall (ZBFW): Deep application-layer inspection for HTTP, FTP, SIP, H.323 and all mainstream enterprise business protocols
2. IOS IPS inline signature-based intrusion prevention with real-time threat detection and automated connection blocking
3. Embedded hardware-accelerated VPN stack:
   • AES-256/3DES/DES IPsec site-to-site branch tunnels
   • Cisco Easy VPN Remote centralized security policy provisioning for remote branch locations
   • DMVPN scalable hub-spoke multi-site overlay networks
   • SSL VPN for browser-only remote worker access without client software
4. AAA security framework: PAP/CHAP authentication, RADIUS/TACACS+ centralized access control and complete audit logging
5. Standard/extended ACLs, dynamic ACLs, anti-DDoS traffic policing, security zone segmentation to isolate sensitive POS payment and finance subnets
6. FIPS 140-2 Level 2 certified with optional FIPS-SHIELD-2951 physical security shield kit for government regulated deployments.

Management, Automation & Operations

• Triple out-of-band management interfaces: RJ45 Serial Console, Mini-USB Console, and AUX modem port for emergency offline IT maintenance
• Secure remote management: SSHv2, HTTPS, SNMP v1/v2c/v3, TR-069 automated remote provisioning
• Graphical configuration utility: Cisco Configuration Professional (CCP) for simplified zero-touch mass branch deployment
• AutoInstall automated remote IOS image and configuration download over WAN links for nationwide branch rollouts
• Dual independent CompactFlash storage for easy IOS upgrade redundancy, configuration backup, and centralized log archiving
• Persistent syslog event logging, NTP time synchronization for consistent audit log timestamps
• Dual USB 2.0 ports for offline config storage and two-factor authentication security tokens
• Cisco EnergyWise power management for intelligent energy consumption control of attached network devices.

4. Typical Deployment Scenarios

1. Large regional enterprise headquarters multi-service edge gateway: Multiple aggregated T1/E1 PRI trunks via high-density VWIC EHWIC, dual fiber Metro Ethernet primary/secondary WAN uplinks via shared SFP slot, VDSL2 EHWIC copper backup link, triple PVDM3 DSP modules supporting over 140 concurrent VoIP calls, three Gigabit Ethernet ports to segregate finance, engineering, staff, and guest VLANs, ISM SRE virtualization module for local application hosting, high-volume DMVPN IPsec tunnels to corporate headquarters, integrated ZBFW/IPS security stack for enterprise compliance.
2. National multi-chain retail flagship voice gateway: ADSL2+ EHWIC primary broadband WAN, ISDN BRI WIC dial backup, CME embedded call processing for 150–200 on-site IP phones, ISM-CUE voice mail storage module, PCI DSS compliant zone firewall for payment network isolation, embedded hardware encryption for hundreds of store site-to-site VPN connectivity.
3. Global mixed POTS/ISDN DSL carrier managed high-capacity enterprise CPE: Universal dual-standard DSL EHWIC copper broadband access, DC power variant for central office rack deployment, ISM WAAS optimization module for tenant bandwidth control, DMVPN overlay to carrier central service hub, integrated firewall/IPS for tenant threat isolation and network segmentation.
4. Advanced enterprise networking training lab flagship core router: Universal EHWIC/WIC/VIC modularity to teach fiber SFP uplinks, high-density multi-T1/E1 PRI voice trunking, triple Gigabit multi-VLAN inter-routing, hardware-accelerated high-volume IPsec VPN, full unified communications gateway, and virtualized SRE application labs; dual CF slots and full 2GB DRAM fully support feature-rich IOS 15.x M images unavailable on all lower-tier 2901/2911/2921 routers.

5. Standard Package Contents of CISCO2951 / 2951-DC / 2951-AC-IP

Separately Sold Optional Accessories

• EHWIC/WIC/VIC/VWIC WAN and analog/digital voice interface cards
• PVDM3 DSP voice compression modules for VoIP, wideband audio and T.38 fax relay
• ISM Internal Service Modules: SRE virtualization, WAAS wide-area optimization, CUE voice mail storage
• DRAM memory expansion DIMMs (512MB / 1GB / 2GB)
• CompactFlash memory upgrades (32MB / 1GB / 4GB)
• CAT5e/CAT6 Gigabit Ethernet patch cords, RJ11 DSL/ISDN telephone line cables
• External PoE injectors for non-PoE IP cameras and wireless access points
• External redundant power supply units (RPS) for high-availability branch deployments
• FIPS-SHIELD-2951 physical security shield kit for FIPS 140-2 compliance

Software Licensing Information

1. SL-29-DATA-K9: Base routing, dual-stack IPv6, MPLS, advanced QoS, NBAR2 application classification, EnergyWise
2. SL-29-SEC-K9: Zone-based firewall, IOS IPS, full IPsec/SSL/DMVPN encryption, advanced threat mitigation, anti-DDoS policing
3. SL-29-UC-K9: CME/SRST embedded voice call processing, Unity Express voice mail, full VoIP codec support for PVDM3 DSPs
   Embedded K9 crypto hardware complies with US ITAR export regulations for global shipments. All licenses are permanent with no recurring subscription fees.

Short Commercial Catalog Summary