Cisco 2651XM Multiservice Modular Access Router (ISR 2600XM Series) Full Product Description

1. Short Overview

Naming & Variant Breakdown

• C2651XM/K9: Base wired rack router with permanent K9 AES/3DES crypto licensing
• C2651XM-DC/K9: 48V DC-powered variant for telecom central office and industrial rack deployments
• -V: Voice pre-licensed bundle with CME/SRST call processing support
• -RPS: Variant compatible with external redundant power supply systems

Core Differentiators vs Base Cisco 2651 (Non-XM)

1. Expanded memory ceiling: Max 256MB SDRAM vs only 128MB on the base 2651; factory default DRAM upgraded to 256MB from 64MB
2. Larger Flash storage: Max 48MB SIMM Flash vs 32MB max on the standard 2651; default Flash increased to 32MB
3. Up to 24,000 pps mixed voice/data/security throughput vs 20,000 pps (~20% performance boost) for concurrent VoIP, firewall, and VPN workloadsCisco
4. Native full support for extended Cisco IOS 12.3T feature trains with advanced voice, security, QoS, and carrier-grade features unavailable on non-XM hardwareCisco
5. Identical modular slot layout, dual onboard Fast Ethernet ports, 80 MHz MPC860P CPU, and physical chassis form factor as the base Cisco 2651
6. Retains dual ISL / IEEE 802.1Q VLAN trunking support and high-density T1/E1 PRI voice trunk compatibility unique to high-tier 2600 models

2. Hardware Interface & Performance Specifications

Modular Expansion Architecture (3 Total Modular Slots + Internal AIM Daughtercard Slot)

1. 1 × NM (Network Module) slot: Large-format high-density slot fully cross-compatible with Cisco 1600, 1700, 2600, 3600 Series modules for voice, WAN, and terminal server deployments:
   • Dual-T1/E1 PRI, single-T1/E1 integrated DSU/CSU network modules for PBX voice interconnection
   • NM-HDV / NM-HDV2 high-density DSP voice modules for analog/digital VoIP trunk telephony and T.38 fax relay
   • ATM, Frame Relay, and 16-port analog modem terminal server modules
2. 2 × WIC (WAN Interface Card) slots: Interchangeable low-density WICs for flexible backup and broadband access:
   • ISDN BRI, synchronous/asynchronous serial leased lines
   • ADSL, G.SHDSL, VDSL2 copper broadband WICs (Annex A/M POTS and Annex B/J ISDN)
   • Dual-port serial and analog modem WICs for dial-on-demand backup links
3. Internal AIM (Advanced Integration Module) daughtercard slot: Accepts AIM-VPN, AIM-VOICE, AIM-ATM, or AIM-COMPRESS modules to offload CPU-intensive IPsec encryption, voice processing, ATM SAR, or data compression without consuming external WAN/NM slots.

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; each port supports both Cisco ISL and IEEE 802.1Q VLAN trunking and inter-VLAN routing to separate distinct internal subnets (e.g., corporate staff LAN, 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 terminal block 48V DC telecom input)
5. Kensington anti-theft lock slot for physical rack chassis security

Memory & Performance Benchmarks

• Processor: Motorola MPC860P PowerQUICC 80 MHz RISC core
• DRAM: 3.3V ECC SDRAM; factory default 256MB, maximum expandable to 256MB (single memory bank)
• Flash memory: Single SIMM Flash slot; default 32MB, maximum supported Flash: 48MB 3.3V SIMM Flash
• Mixed voice/data packet forwarding throughput: Up to 24,000 packets per second (pps) under full multi-service load
• Onboard hardware crypto engine + AIM-VPN offload support: Native AES-256, 3DES, DES IPsec and SSL VPN acceleration
• Maximum concurrent site-to-site IPsec tunnels: Up to 100 (scales with DRAM and AIM-VPN crypto module)
• Supported IOS releases: Cisco IOS 12.2T, 12.3 mainline / 12.3T multiservice maintenance trains (XM models unlock extended voice, security, and QoS features unavailable on non-XM 2651)Cisco
• Voice capacity: Compatible with NM-HDV2 DSP modules for up to 192 concurrent VoIP calls, multi-party conferencing, and T.38 fax relay; supports Cisco CME for up to 72 IP phones

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 (C2651XM-DC): 48V DC terminal block input for telecom central office racks
• Typical chassis power draw: ~60W under fully loaded 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: ~4.8 kg (10.6 lbs) fully loaded with NM/WIC/AIM modules
• No native chassis PoE output; IP cameras and wireless APs require external PoE injectors.

3. Cisco IOS Multiservice Feature Suite

Core Routing & Multi-WAN Connectivity

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

Multiservice Voice & Fax Integration (Key High-Density Voice Differentiator)

1. VoIP call control protocols: H.323, SIP, MGCP, SCCP 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, E1/T1 PRI trunk interworking with third-party PBXs (Nortel, Siemens, Avaya)
3. T.38 real-time fax relay over IP, fax passthrough, store-and-forward fax
4. Voice compression codecs: G.711, G.729a, G.726 with hardware DSP acceleration to reduce WAN bandwidth consumption
5. Multi-site dial plans, voice hunt groups, toll bypass to eliminate costly long-distance PSTN telephony charges
6. Cisco CME embedded call processing for up to 72 IP phones, Unity Express voice messaging support via AIM storage modules

Enterprise QoS & Bandwidth Management

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

Integrated Self-Defending Network Security

1. IOS Context-Based Access Control (CBAC) stateful firewall: Dynamic deep packet inspection for HTTP, FTP, SIP, H.323, and other business applications
2. Optional IOS signature-based IDS for inline intrusion detection and real-time threat mitigation
3. Hardware-accelerated VPN suite (with AIM-VPN module):
   • AES-256/3DES/DES IPsec site-to-site branch tunnels
   • Cisco Easy VPN Remote for centralized security policy deployment to remote branch locations
   • DMVPN for 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 audit logging
5. Standard/extended ACLs, dynamic ACLs, anti-DDoS policing, and traffic segmentation to isolate sensitive subnets (e.g., POS payment VLANs).

Management & Operations

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

4. Typical Deployment Scenarios

1. Medium multi-line retail flagship voice gateway: VDSL2 WIC primary broadband WAN, ISDN BRI WIC dial backup, NM-HDV2 high-density DSP module for dozens of store analog phones and fax machines, dual Fast Ethernet ports to isolate POS payment terminals from employee PC and guest Wi-Fi subnets, IPsec site-to-site DMVPN tunnel to corporate headquarters, integrated CBAC firewall for PCI DSS compliance.
2. Regional medium enterprise PBX interconnection router: Dual T1 PRI NM leased-line primary/secondary voice trunks to on-site PBX, analog modem AUX-port remote out-of-band management, multi-VLAN segmentation for finance, HR, engineering, and visitor subnets, LLQ QoS prioritization for business VoIP and video conferencing.
3. Networking training lab high-density voice core router: Flexible NM/WIC modularity to teach serial, T1/E1 PRI, DSL, ISDN WAN connectivity, dual-standard ISL/802.1Q VLAN trunking, IPsec VPN, and enterprise voice gateway labs; expanded memory supports full-featured IOS 12.3T images unavailable on the base 2651.
4. Global mixed POTS/ISDN DSL carrier managed voice-capable business CPE: Universal dual-standard DSL WIC copper access, dual Fast Ethernet ports for multi-segment enterprise LAN, integrated firewall and IDS for customer threat protection, DMVPN overlay to carrier central service hub, CME embedded IP phone call processing for on-site staff.

5. Standard Package Contents of C2651XM / C2651XM-DC

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 encryption, AIM-VOICE DSP offload, AIM-ATM, AIM-COMPRESS data compression modules
• DRAM memory expansion SIMMs (128MB / 256MB)
• 3.3V SIMM Flash memory upgrades (32MB / 48MB)
• CAT5e/CAT6 Gigabit 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