ISR4221/K9 – 2×GE WAN/LAN Ports – 2×NIM Slots – ISR 4221 Router
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ISR4221/K9 Description
Cisco ISR4221/K9, also called ISR 4221 or Cisco 4221 router, is the entry-level model in the Cisco 4000 Series Integrated Services Routers. Designed for small offices and remote branches, it provides two Gigabit Ethernet ports (one RJ-45 and one SFP), two NIM slots for WAN or voice modules, and license-based throughput scalability from 35 Mbps to 75 Mbps. The router has fixed DRAM (4 GB or 8 GB for ISR4221X) and flash memory, with no SM-X or on-board PVDM slots. While it does not support PoE, it maintains modularity with WAN, xDSL, LTE, and serial NIMs, making it a cost-effective and secure solution for entry-level branch connectivity.
Product Highlights
Front View
|
1 |
Grounding |
2 |
Power input connector |
|
3 |
Power switch |
4 |
USB |
|
5 |
Console port |
6 |
GE 0/0/0 RJ-45 (copper cable) port |
|
7 |
GE 0/0/0 SFP (fiber-optic) port |
8 |
GE 0/0/1 (copper cable) port |
Quick Specs
|
Parameter |
Specification |
|---|---|
|
GE Ports |
2 × 10/100/1000 (1 × RJ-45, 1 × SFP) |
|
NIM Slots |
2 |
|
SM-X Slot |
None |
|
On-board PVDM/ISC |
None |
|
Aggregate Throughput |
35–75 Mbps (licensed) |
|
Default / Max DRAM |
4 GB / 4 GB (4221), 8 GB fixed (4221X) |
|
Default / Max Flash |
8 GB / 8 GB |
|
Power with PoE |
Not supported (no PoE PSU option) |
|
Rack Units |
1 RU |
|
Weight |
~3.2–3.7 kg (depending on PSU type) |
Key Features
Entry-Level Branch Routing with Flexible Performance
ISR4221/K9 provides 35–75 Mbps throughput under license, offering an affordable starting point for small offices and scaling as bandwidth needs increase.
Compact Modular Design
With 2 NIM slots, the router supports WAN diversity such as LTE, xDSL, serial, and PRI/BRI, allowing branches to adapt to changing access requirements.
Voice and Collaboration Support via Modules
Compatible with voice NIMs that include onboard PVDM4 DSPs, enabling SRST, transcoding, and conferencing to keep local telephony operational during WAN outages.
Secure WAN Edge for Small Sites
Integrated IOS XE security features, VPN encryption, and SD-WAN readiness make the ISR4221 suitable for distributed enterprises with compliance-driven connectivity needs.
Low Power and Silent Efficiency
Lightweight 1RU form factor, low acoustic profile, and efficient energy use make it ideal for constrained retail or office environments where space and noise matter.
Simple Deployment and Remote Management
Zero-touch provisioning, centralized management with Cisco Catalyst Center, and compatibility with Cisco DNA licensing simplify operations for lean IT teams.
Application Scenarios
Provides secure VPN connectivity for POS transactions, supports LTE backup modules for continuity, and offers optional EtherSwitch NIMs for powering limited branch devices.
Delivers reliable WAN connectivity with encrypted tunnels, while supporting local SRST voice through voice NIMs to maintain communication during outages.
Affordable and compact, ISR4221 is ideal for small agencies, schools, or local offices that require modular WAN expansion, secure hybrid WAN, and easy-to-manage routing at the edge.
Product Comparison
|
Feature |
ISR4221/K9 | ||
|---|---|---|---|
|
GE Ports |
2 (1 RJ-45, 1 SFP) |
2 (RJ-45/SFP combo) |
3 (2 combo + 1 RJ-45) |
|
NIM Slots |
2 |
2 |
2 |
|
SM-X Slot |
None |
None |
1 |
|
On-board PVDM/ISC |
None |
None (voice via NIMs) |
1 |
|
DRAM Default / Max |
4 / 4 GB (8 GB fixed on 4221X) |
4 / 8 GB |
4 / 16 GB |
|
Flash Default / Max |
8 / 8 GB |
4 / 8 GB |
4 / 16 GB |
|
Aggregate Throughput |
35–75 Mbps |
50–100 Mbps |
100–300 Mbps |
|
PoE Budget Max |
Not supported |
125 W (via EtherSwitch NIM) |
250 W |
|
Rack Units |
1 RU |
1 RU |
1 RU |
|
Weight |
~3.2–3.7 kg |
~4.8 kg |
~5.6 kg |
ISR4221/K9 Supported Modules
|
Module Type / Part Numbers |
Supported on ISR4221/K9 |
|---|---|
|
Network Interface Modules (NIMs) |
Yes – 2 slots (single-wide or one double-wide with divider) |
|
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-ES2-8 / NIM-ES2-8-P |
Yes (no PoE output on ISR4221) |
|
NIM-SSD / NIM-HDD |
Yes |
|
NIM LTE / xDSL variants |
Yes (regional SKUs apply) |
|
Service Modules (SM-X) |
Not supported |
|
On-board PVDM4 |
Not supported (voice via NIM DSPs) |
|
SFP Modules |
Supported (100M/1G SFP) |
|
Legacy WIC/EHWIC |
Not supported |
Specifications
| Parameter | Specification | Parameter | Specification |
|---|---|---|---|
| Model | ISR4221 (Cisco 4000 Series ISR) | Form Factor | 1RU rack-mount |
| GE Ports | 2 (1 RJ-45, 1 SFP) | NIM Slots | 2 |
| SM-X Slot | None | On-board PVDM/ISC | Not present (voice DSP via NIMs) |
| DRAM | 4 GB fixed (4221), 8 GB fixed (4221X) | Flash | 8 GB fixed |
| Aggregate Throughput | 35–75 Mbps (licensed) | Encryption | Hardware-assisted VPN |
| USB Ports | USB 2.0 Type-A, mini-USB console | Console / AUX | RJ-45 console, RJ-45 auxiliary |
| Operating System | Cisco IOS XE | Power Supply | External AC PSU only |
| PoE Capability | Not supported | Cooling | Integrated fan system |
| Operating Temp | 0–40 °C | Humidity | 5%–85% non-condensing |
| Dimensions (H×W×D) | 1.72 × 12.7 × 10 in (43.7 × 322.6 × 254 mm) | Weight | ~3.2–3.7 kg |
| Compliance | IEC/EN/UL 60950-1/62368-1, CISPR 22/24 Class A | Licensing | Performance, Security, UC, AppX |
Get More Information
Need pricing, stock, or shipping details for the ISR4221/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.
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Customer Reviews
Questions & Answers
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What is ISR4221/K9 used for?
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What throughput can ISR4221/K9 provide?
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How many onboard Gigabit Ethernet ports does ISR4221/K9 have?
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What module slots are on ISR4221/K9?
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How is ISR4221/K9 different from ISR4221X/K9?
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How is ISR4221/K9 different from ISR4321/K9?
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Can ISR4221/K9 use performance licensing?
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What memory and flash are listed for ISR4221/K9?
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