| Parameter Category | Parameter | Specification |
| Chassis & Design | Model | CISCO1921/K9 |
| | Form Factor | 1RU (Rack-mountable, 19-inch optional) |
| | Integrated Components | Fixed configuration, all components integrated |
| | Airflow | Back to sides |
| Performance | Embedded Crypto Acceleration | Yes (IPsec + SSL) |
| Interfaces | Built-in Gigabit Ethernet Ports | 2 x 10/100/1000Base-T (RJ-45) |
| | Expansion Slot(s) | 2 x Enhanced High-Speed WAN Interface Card (EHWIC) slots |
| | Doublewide EHWIC slots | 1 (consumes 2 EHWIC slots) |
| | Cisco Integrated Services Module (ISM) slots | 0 |
| | Management Ports | 1 x Serial Console (RJ-45, up to 115.2 kbps), 1 x USB Console (mini-Type B, up to 115.2 kbps), 1 x Serial Auxiliary (RJ-45, up to 115.2 kbps) |
| | USB Ports | 1 x External USB flash memory slot (Type A) |
| Memory | DRAM (Default/Maximum) | 512 MB / 512 MB (DDR2 DRAM) |
| | Flash Memory (Internal Default/Maximum) | 256 MB / 256 MB (USB Flash memory) |
| Power | Integrated Power Supply | AC and DC power-supply models |
| | Power Supply Options | PoE (external) - on AC models only |
| | Redundant Power Supply Support | No |
| | AC Input Voltage | 100-240V ~ |
| | AC Input Frequency | 47-63 Hz |
| | Typical Power (no modules) | 25W |
| | Maximum Power Capacity (AC Power Supply) | 60W |
| | Maximum PoE Device Power Capacity (PoE PS) | 80W |
| | DC Power Input | 32-60 VDC, 4A (positive or negative, single source) |
| Software & Security | Operating System | Cisco IOS IP Base (default) |
| | Security Features | Embedded hardware-based cryptography acceleration (IPsec + SSL), Firewall protection, VPN support |
| Physical Specifications | Dimensions (H x W x D) | 1.75 x 13.5 x 11.5 in. (4.45 x 34.29 x 29.21 cm) |
| | Weight (with AC power supply, no modules) | 6.75 lb (3.06 kg) |
| | Rack-mount | Optional (19-inch EIA) |
| | Wall-mount | Yes (refer to installation guide for approved orientation) |
| Environmental | Operating Temperature (0-1800m altitude) | 0°C to 40°C (32°F to 104°F) |
| | Operating Temperature (0-3000m altitude) | 0°C to 25°C (32°F to 77°F) |
| | Operating Humidity | 10% to 85% relative humidity (non-condensing) |
| | Operating Altitude | Up to 3,000m (10,000 ft) |
| | Storage Temperature | -40°C to 70°C (-40°F to 158°F) |
| | Storage Humidity | 5% to 95% relative humidity (non-condensing) |
| | Acoustic Sound Pressure (typical/maximum) | 32.99/58.33 dBA |
| Regulatory Compliance | Safety | UL 60950-1, CAN/CSA C22.2 No. 60950-1, EN 60950-1, AS/NZS 60950-1, IEC 60950-1 |
| | EMC | 47 CFR, Part 15 Class A, ICES-003 Class A, EN55022 Class A, CISPR22 Class A, AS/NZS 3548 Class A, VCCI V-3, EN 300-386, EN 61000 (Immunity), EN 55024, CISPR 24, EN50082-1 |
| | Telecom | TIA/EIA/IS-968, CS-03, ANSI T1.101, IEEE 802.3, RTTE Directive |
| End-of-Life (EOL) Status | End-of-Sale Date | September 29, 2018 |
| | Last Date of Support | September 30, 2023 |
