QFX5120-48YM-AFO - Juniper QFX5120-48YM-AFO 2.9Tbps 48x25GbE Switch

Name: Juniper QFX5120-48YM-AFO 2.9Tbps 48x25GbE Switch
Brand: Juniper
SKU: QFX5120-48YM-AFO

QFX5120-48YM-AFO - Juniper QFX5120-48YM-AFO 2.9Tbps 48x25GbE Switch | US IT Hardware

Product overview

The Juniper QFX5120-48YM-AFO is a high-performance, high-density data center leaf and campus distribution switch engineered for modern cloud infrastructure and enterprise deployments. This 1U platform delivers up to 2.9 Tbps bidirectional switching capacity with ultra-low 800-nanosecond latency, supporting 48 downlink ports at 25GbE (SFP28) with backward compatibility to 10GbE and 1GbE, plus eight 100GbE (QSFP28) uplink ports for spine connectivity. The AFO variant features front-to-back airflow optimized for hot-aisle deployment in high-density data centers. Built-in MACsec AES-256 encryption across all ports provides wire-speed security without performance degradation. The switch includes a 2.9 GHz quad-core Intel CPU, 16 GB DRAM, and 100 GB SSD for advanced routing, switching, and service functions. Dual redundant 850W AC power supplies with 1+1 redundancy ensure high availability. Comprehensive management includes role-based CLI, SNMP v1/v2/v3, sFlow v5, and Junos XML API. Ideal for data center spine-leaf architectures, cloud service providers, and large-scale campus networks requiring non-blocking performance and security at scale.

2.9Tbps bidirectional switching capacity.
48x25GbE SFP28 + 8x100GbE QSFP28 ports.
800 nanosecond latency for low-latency apps.
MACsec AES-256 encryption on all ports.
1U form factor with dual 850W AC PSUs.
Intel quad-core CPU, 16GB RAM, 100GB SSD.

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Purchase orders accepted from qualified institutions.
Refunds within 14 days and replacements within 30 days of delivery with an RMA (25% restocking fee on customer-initiated returns), and every part carries our Standard 30-Day Warranty - see our return policy or contact US IT Hardware.

Featuring

Management Protocols
Manufacturer part #	QFX5120-48YM-AFO
Brand	Juniper
Condition	New
Model	QFX5120-48YM-AFO
ESD Point	Yes, ESD grounding point on rear panel
Product Line	QFX5120 Series
Product Type	Data Center Ethernet Switch
Reset Button	Yes, rear panel reset button
Operating System	Junos OS (current and recent releases)
Variant Designation	AFO = front-to-back airflow (hot-aisle deployment). Other variants: AFI (back-to-front, cold-aisle), DC-AO/DC-AI (DC power supplies)

Compatible systems

QFX5120-48YM-AFO is compatible with standard SFP28, SFP+, SFP, QSFP28, and QSFP+ transceivers. Operates within Juniper QFX5120 series ecosystem and integrates with Junos OS management framework. Requires standard optical cabling and transceivers (sold separately). Dual AC power supplies provide redundancy. Front-to-back airflow design requires hot-aisle deployment environment. Management via Ethernet (RJ-45) or serial console.

Juniper Networks QFX5120 Series
Model: QFX5120-48YM-AFO
Form factor: 1U rack-mount switch
Generation: QFX5120 (current generation)
Operates as standalone switch or in spine-leaf fabric with other QFX5120 models (QFX5120-48Y, QFX5120-48T variants). Compatible with Juniper QFX5100 and QFX5200 series in multi-tier data center architectures.

Best for

Data Center Spine-Leaf Architecture
Serves as high-capacity spine switch aggregating multiple leaf switches in large-scale data center fabrics, supporting 100GbE uplinks to other spines and 25GbE downlinks to leaf switches with non-blocking performance.
Cloud Service Provider Networks
Enables multi-tenant cloud infrastructure with MACsec AES-256 encryption for tenant isolation, 2.9Tbps capacity for massive east-west traffic, and low 800ns latency for time-sensitive workloads.
High-Performance Computing (HPC)
Supports HPC cluster interconnects with 25GbE per-node connectivity and 100GbE inter-cluster links, delivering predictable low-latency performance for tightly-coupled parallel applications.

Details

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Configuration Management	Configuration rescue, rollback, image rollback, extended ping/traceroute

Storage	100 GB SSD

CPU	2.9 GHz quad-core Intel processor
Memory	16 GB DRAM

Latency	800 nanoseconds
Packet Forwarding Rate	Not specified in available sources
Switching Capacity Bidirectional	2.9 Tbps
Switching Capacity Unidirectional	4 Tbps

Security Features	MACsec AES-256 encryption on all ports (hardware-accelerated, zero performance impact)

Power Consumption

Power Supply Type	AC (AFO variant uses JPSU-850W-AC-AFO)
Power Supply Count	2
Power Supply Capacity	850W per supply
Power Supply Hot-Swap	Yes, hot-removable and hot-insertable
Power Supply Redundancy	1+1 (N+1 redundancy, both supplies active)
Maximum Power Consumption	460W (446W base + 14W with MACsec enabled)
Typical Power Consumption	291W (280W base + 11W with MACsec enabled)

Physical Characteristics

Dimensions	1U form factor (1.73 inches height), standard 19-inch rack mount
Rack Mount	Yes, standard 19-inch rack
Form Factor	1U rack-mount
Fan Module Count	5
Fan Module Model	QFX5110-FANAFO (front-to-back airflow variant)
Airflow Direction	Front-to-back (AFO variant, airflow exits front for hot-aisle deployment)

Environmental

Airflow Volume	126 CFM per fan module, 5 fan modules total
Operating Altitude	Up to 6000 feet (1828 meters)
Operating Humidity	5% to 90% relative humidity, non-condensing
Storage Temperature	-40°C to 70°C (-40°F to 158°F)
Operating Temperature	0°C to 40°C (32°F to 104°F)

Interface/Ports

USB Port	1x USB Type-A port
Console Port	1x RJ-45 serial console port
Timing Ports	1x 10 MHz output port, 1x PPS (pulse-per-second) output port
Uplink Ports	8x QSFP28 (100GbE native, backward compatible to 40GbE QSFP+)
Downlink Ports	48x SFP28 (25GbE native, backward compatible to 10GbE SFP+ and 1GbE SFP)
Management Ports	2x 1GbE RJ-45 Ethernet management ports
Status Indicators	Chassis status LEDs (ALM, SYS, MST, ID), fan module LEDs, beacon LEDs for port/system status
Uplink Port MACsec Support	Yes, all uplink ports support MACsec AES-256
Downlink Port Breakout Support	Ports 50 and 52 support breakout cables for 4x10GbE or 4x25GbE per port, enabling up to 56 total 25GbE/10GbE ports

Frequently asked questions

What is the switching capacity and throughput of the QFX5120-48YM-AFO?

The QFX5120-48YM-AFO delivers up to 2.9 Tbps bidirectional (4 Tbps unidirectional) non-blocking switching capacity with latency as low as 800 nanoseconds. This supports simultaneous wire-speed forwarding across all 48x25GbE downlink ports and 8x100GbE uplink ports, enabling full-duplex performance without congestion or packet loss in data center deployments.

How does MACsec encryption impact performance on this switch?

MACsec AES-256 encryption is implemented in hardware across all ports with zero performance impact. Maximum power consumption increases from 446W to 460W with MACsec enabled, and typical power draw increases from 280W to 291W. The switch maintains full 2.9Tbps throughput and 800ns latency even with encryption active, making it suitable for security-sensitive environments without sacrificing performance.

What are the downlink port options and backward compatibility?

The 48 downlink ports use SFP28 transceivers supporting 25GbE natively, with backward compatibility to 10GbE (SFP+) and 1GbE (SFP) transceivers. Ports 50 and 52 support breakout cables enabling up to 56 total 25GbE or 10GbE ports. This flexibility allows mixed-speed deployments, gradual network upgrades, and integration with existing 10GbE infrastructure without requiring forklift replacement.

What management and monitoring capabilities does the QFX5120-48YM-AFO provide?

Management includes role-based CLI access via console (RJ-45), telnet, or SSH; SNMP v1/v2/v3 for monitoring; Junos XML API for programmatic control; and sFlow v5 for traffic analytics. The switch includes a 2.9 GHz quad-core Intel CPU with 16GB DRAM and 100GB SSD, supporting advanced Junos OS features like configuration rollback, image rollback, extended ping/traceroute, and beacon LEDs for port/system status visibility.

How is the AFO variant different from other QFX5120-48YM models?

The AFO designation indicates front-to-back airflow (airflow exits the front for hot-aisle deployment), contrasting with AFI (back-to-front, cold-aisle). Both use identical 5x fan modules with 126 CFM airflow volume and identical QSFP28 uplink ports. The AFO variant uses JPSU-850W-AC-AFO power supplies with front-to-back PSU airflow, while DC variants (DC-AO) use DC power supplies. Cooling and power consumption specifications are identical across all variants.

What are the environmental operating specifications and power requirements?

Operating temperature range is 0–40°C (32–104°F) with maximum altitude of 6000 feet (1828m) and 5–90% relative humidity (non-condensing). AC power models consume 460W maximum (291W typical) with dual 850W redundant supplies providing 1+1 failover. Both PSUs are hot-removable and hot-insertable. Storage temperature range is -40–70°C (-40–158°F). The 1U form factor (1.73 inches height) fits standard 19-inch racks with front-to-back airflow optimized for high-density data center cooling.

What uplink and management port options are available?

Eight QSFP28 uplink ports support 100GbE natively with backward compatibility to 40GbE (QSFP+). All uplink ports support MACsec. Management includes two 1GbE RJ-45 management ports, one RJ-45 console port, one USB Type-A port, one 10 MHz timing output port, and one PPS (pulse-per-second) output port for precision timing synchronization in financial and telecom networks. These auxiliary ports enable out-of-band management and timing-critical applications.

Juniper QFX5120-48YM-AFO 2.9Tbps 48x25GbE Switch