ISR4351/K9 – 3×GE WAN/LAN Ports – 3×NIM Slots – ISR 4351 Router
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ISR4351/K9 Description
Cisco ISR4351/K9 (also called ISR 4351 or Cisco 4351 router) is a high‑performance branch router in the Cisco 4000 Series. It features three Gigabit Ethernet ports (two combo RJ‑45/SFP and one RJ‑45), three NIM slots, and one SM‑X service‑module slot to consolidate WAN, voice, security, and application services on a single platform. With 200–400 Mbps aggregate throughput (via performance licensing), up to 16 GB DRAM, and 500 W PoE capacity through supported EtherSwitch modules, ISR4351 is ideal for mid‑to‑large branches that need scalable WAN performance, unified communications, and on‑box service flexibility.
Product Highlights
Quick Specs
|
Parameter |
Specification |
|---|---|
|
GE Ports |
3 × 10/100/1000 (2 × RJ‑45/SFP combo + 1 × RJ‑45) |
|
NIM Slots |
3 |
|
SM‑X Slot |
1 |
|
ISC (PVDM4) |
1 |
|
Aggregate Throughput |
200–400 Mbps (licensed) |
|
Default / Max DRAM |
4 GB / 16 GB |
|
Default / Max Flash |
4 GB / 16 GB |
|
Max Power with PoE |
500 W |
|
Rack Units |
2 RU |
|
Weight |
~18.5 lb (8.4 kg) |
Key Features
Scalable Branch Performance
Delivers 200–400 Mbps aggregate throughput, ensuring smooth growth for branch WAN, VPN, and cloud workloads without forklift upgrades.
Rich Modularity
Supports 3× NIM and 1× SM-X slots, enabling integration of WAN optimization, security, LTE/xDSL, or switching modules tailored to diverse branch requirements.
Advanced Unified Communications
With PVDM4 DSPs and voice NIMs, it provides SRST, conferencing, and transcoding, ensuring branch survivability and high-quality voice services.
Integrated Security
Offers hardware-accelerated VPN and policy-based segmentation, essential for hybrid cloud, SD-WAN, and compliance-driven industries.
High PoE Capacity
Up to 500 W PoE budget when combined with PoE-capable EtherSwitch NIM/SM-X modules, allowing direct powering of IP phones, wireless access points, and surveillance cameras.
Enterprise-Grade Reliability
Built with field-replaceable PSUs, robust thermal management, and Cisco IOS XE software for long-term, stable branch operations.
Application Scenarios
ISR4351 is ideal for medium to large branch offices that need secure WAN aggregation, application visibility, and integrated collaboration services.
Delivers high-availability WAN, encrypted VPN, and multi-service aggregation for industries where uptime, compliance, and secure transactions are critical.
Enables converged services, such as secure inter-site connectivity, IP telephony, and IoT device integration, within regulated and mission-critical environments.
Front View
|
1 |
Power supply unit |
2 |
Router fan tray (hidden behind the removable bezel) |
|
3 |
LEDs |
4 |
Router power On/Off switch |
Rear View
|
1 |
Enhanced Service Module (SM-X) slot |
2 |
Enhanced Service Module (SM-X) slot |
|
3 |
Ground connection |
4 |
NIM slots |
|
5 |
GE management port |
6 |
USB Type A port |
|
7 |
USB Type B mini port |
8 |
Auxiliary port |
|
9 |
Console port |
10 |
RJ-45 port (GE 0/0/0, GE 0/0/1) |
|
11 |
SFP port (GE 0/0/0, GE 0/0/1, GE 0/0/2) |
12 |
RJ-45 port (GE/0/0/2) |
Product Comparison
|
Feature |
ISR4351/K9 | ||
|---|---|---|---|
|
GE Ports |
2 (2 combo) |
3 (2 combo + 1 RJ‑45) |
3 (2 combo + 1 RJ‑45) |
|
NIM Slots |
2 |
2 |
3 |
|
SM‑X Slot |
– |
1 |
1 |
|
ISC (PVDM4) |
– |
1 |
1 |
|
Default / Max DRAM |
4 GB / 8 GB |
4 GB / 16 GB |
4 GB / 16 GB |
|
Default / Max Flash |
4 GB / 8–16 GB |
4 GB / 16 GB |
4 GB / 16 GB |
|
Aggregate Throughput |
50–100 Mbps |
100–300 Mbps |
200–400 Mbps |
|
Max Power with PoE |
125 W |
250 W |
500 W |
|
Rack Units |
1 RU |
1 RU |
2 RU |
|
Weight |
~10.6 lb |
~12.25 lb |
~18.5 lb |
|
Voice DSP (PVDM4) |
Supported via NIM |
Supported |
Supported |
|
PoE Availability |
Via EtherSwitch NIM + PoE PSU |
EtherSwitch NIM/SM‑X + PoE PSU |
EtherSwitch NIM/SM‑X + PoE PSU |
ISR4351/K9 Supported Modules
|
Module Type / Part Numbers |
Supported on ISR4351/K9 |
|---|---|
|
Network Interface Modules (NIMs) |
Yes – 3 slots (single-wide; double-wide supported with divider removed) |
|
NIM-1GE-CU-SFP / NIM-2GE-CU-SFP |
Yes |
|
NIM-1MFT-T1/E1 / NIM-2MFT-T1/E1 |
Yes |
|
NIM-4MFT-T1/E1 / NIM-8MFT-T1/E1 |
Yes |
|
NIM-1CE1T1-PRI / NIM-2CE1T1-PRI |
Yes |
|
NIM-8CE1T1-PRI |
Yes |
|
NIM-ES2-8 / NIM-ES2-8-P (EtherSwitch) |
Yes (PoE requires PoE-capable PSU) |
|
NIM-SSD / NIM-HDD (Storage) |
Yes |
|
NIM LTE / xDSL variants |
Yes (regional SKUs apply) |
|
Service Modules (SM-X) |
Yes – 1 slot for Enhanced Service Modules |
|
SM-X-ES3-16-P / 24-P / 48-P |
Yes |
|
UCS-E compute/virtualization SM |
Yes (subject to PSU/thermal capacity) |
|
Packet Voice DSP (PVDM4) |
Yes – 1 ISC bay on motherboard |
|
PVDM4-32 / 64 / 128 / 256 |
Yes |
|
Cisco UCS E-Series Server Modules |
Not supported (only on ISR 4400 Series) |
|
Integrated PoE Daughter Card |
Not supported on built-in GE ports |
|
PoE via EtherSwitch NIMs/SM-X |
Supported (up to 500 W with PoE PSU) |
|
Power Supply Options |
AC PSU (default), DC PSU optional |
|
Hot-Swap Dual PSU |
Not supported on ISR4351 |
|
SFP Modules |
Supported (100M/1G SFPs on combo ports) |
|
Legacy WIC/EHWIC Cards |
Not supported (4000-Series uses only NIM/SM-X) |
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Model | ISR4351 (Cisco 4000 Series ISR) | Form Factor | 2RU rack-mount |
| GE Data Ports | 3 × 10/100/1000 (2 × RJ‑45/SFP combo + 1 × RJ‑45) | Dedicated Mgmt | Integrated management via front-panel GE |
| NIM Slots | 3 (single‑wide; double‑wide supported per divider) | SM‑X Slot | 1 (Enhanced Service Module) |
| ISC / PVDM4 | 1 ISC bay for PVDM4 DSP modules | USB Ports | USB 2.0 Type‑A (storage), mini‑USB console |
| Console / AUX | RJ‑45 console and RJ‑45 auxiliary | OS | Cisco IOS XE |
| Default / Max DRAM | 4 GB / 16 GB | Default / Max Flash | 4 GB / 16 GB |
| Aggregate Throughput | 200–400 Mbps (licensed) | Encryption Capability | Hardware‑accelerated (license dependent) |
| WAN/LAN via Modules | Provided through NIM/SM‑X (T1/E1, Serial, xDSL, LTE, L2/L3 Switch) | SFP Support | 100/1000‑Mb SFPs on combo ports |
| Power Supply | AC PSU (default); DC PSU option | Max PoE Budget | Up to 500 W with PoE‑capable PSU & modules |
| Cooling | Integrated fans with smart control | Operating Temp | 0–40 °C (32–104 °F) |
| Operating Humidity | 10%–90% non‑condensing | Altitude (Operating) | ‑500 to 10,000 ft |
| Dimensions (HxWxD) | ~3.5 × 17.25 × 17.5 in (2RU height) | Weight | ~18.5 lb (8.4 kg) |
| Compliance | Safety: IEC/EN/UL 60950‑1/62368‑1; EMC: CISPR 22/24 Class A (region dependent) | Mounting | 19‑inch EIA rack; optional accessories available |
| Licensing | Performance, Security, UC, AppX (Smart Licensing) | Typical Roles | Branch WAN/Internet gateway, UC gateway, converged services |
Get More Information
Need pricing, stock, or shipping details for the ISR4351/K9 ? Layer23-Switch can help you check current availability, lead time, and delivery options for this. Send us the part number, quantity, and destination country via live chat or email sales@layer23-switch.com for a fast quotation.
Quality Certifications
Customer Reviews
Questions & Answers
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What is ISR4351/K9 used for?
-
What throughput can ISR4351/K9 reach?
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What onboard Ethernet ports are on ISR4351/K9?
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What module slots does ISR4351/K9 provide?
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How is ISR4351/K9 different from ISR4331/K9?
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Does ISR4351/K9 fit voice gateway deployments?
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What memory and flash are listed for ISR4351/K9?
-
When does ISR4351/K9 make sense instead of ISR4431/K9?
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Hope is not a strategy, good hardware is. This router is reliable.
3 GE ports and SM slots give us room to grow. Voice modules work perfectly.