Cisco 400 Gigabit QSFP-400G-VR4 Transceiver

Product overview

Cisco 400G QSFP112 modules deliver high-performance, power-efficient connectivity optimized for AI/ML fabrics, high-performance computing, and modern data center networks. Built on 100G-per-lane PAM4 signaling, Quad Small Form-factor Pluggable (QSFP)112 enables 400 Gigabit Ethernet in a compact, thermally efficient form factor ideal for high-density AI and cloud deployments. QSFP112 is widely adopted across the ecosystem and supports flexible architectures, including breakout configurations for scalable leaf/spine and multi-plane AI fabric designs with connectivity into high-speed
Network Interface Cards (NIC).

The Cisco QSFP-400G-DR4 module supports 400GBASE-DR4 links over parallel single-mode fiber using MPO-12 connectivity, with support for breakout connections up to 500 meters. The Cisco QSFP-400G-VR4 module delivers short-reach multimode connectivity optimized for high-density AI and cloud environments, using MPO-based multimode fiber infrastructure supporting reaches up to 50 meters. The Cisco QSFP-400G-FR4 module provides duplex single-mode fiber connectivity using LC connectors and wavelength multiplexing technology, supporting reaches up to 2 kilometers over Single Mode Fiber (SMF) while reducing fiber count and simplifying migration from existing duplex fiber infrastructure.

Together, these transceivers provide deployment flexibility across multimode and singlemode environments, supporting scalable AI back-end and front-end network architectures with high reliability, low power consumption, and standards-based interoperability.

Table 1.           Features and benefits

Table 2.           Cisco QSFP112 portfolio

Note: For more information and references on Cisco transceiver cables, please visit Cisco Transceiver Modules – Brochures – Cisco.

QSFP-400G-DR4

The Cisco QSFP-400G-DR4 module (Figure 1) supports 400GBASE-DR4 links and up to four 100G DR1 or two 200G DR2 breakout link lengths of up to 500 m. The module has four pairs of single-mode fiber (SMF) with an MPO-12 connector. It is compliant with the IEEE 802.3 and 400GAUI-4 standards. The 400G signal is carried over four pairs of parallel fibers by one wavelength per fiber. It can be used 200G DR2 link for 200GE ports by using two pairs of fibers. Forward Error Correction (FEC) is performed on the host platform.

QSFP-400G-VR4

The Cisco QSFP-400G-VR4 module (Figure 2) supports 400GBASE-VR4 links and up to four 100G VR1 or two 200G VR2 breakout links over multimode fiber (MMF). The module has four pairs of multi-mode fiber (MMF) with an MPO-12 connector. It is compliant with IEEE 802.3 and 400GAUI-4 standards. The 400G signal is transmitted over four parallel multimode fiber pairs using PAM4 signaling at 100Gbps per lane. The module can also operate in 200G breakout mode using two optical lanes for 200GE connectivity. Forward Error Correction (FEC) is performed on the host platform.

The Cisco QSFP-400G-FR4 module delivers 400 Gigabit Ethernet connectivity over duplex single-mode fiber (SMF) using LC connectors and wavelength-division multiplexing (WDM) technology. Designed for AI/ML fabrics, cloud networking, and high-density data centers, the module supports reaches up to 2 kilometers over standard G.652 SMF while reducing fiber complexity compared to parallel optics. QSFP-400G-FR4 uses four 100G PAM4 optical wavelengths multiplexed onto a duplex fiber pair, enabling efficient migration from existing duplex fiber infrastructure with lower cabling density and operational overhead. Compliant with IEEE 400GBASE-FR4 and 400GAUI-4 standards, the module provides low-power, standards-based interoperability for modern leaf/spine architectures and high-performance Ethernet fabrics.

Table 3.           QSFP port and cabling specifications

Platform support

Cisco QSFP112 modules are primarily supported on NICs providing Ethernet connectivity to servers for a variety of applications. For more details, refer to the Cisco Transceiver Modules Compatibility Matrix.

Specifications

Table 4.           Electrical specifications

Table 5.           Optical specifications

Table 6.           Mechanical specifications

Table 7.           Temperature range

Cisco Transceiver Qualification and Validation on Third-Party Network Interface Cards

Cisco performs extensive interoperability and qualification testing of its transceivers with a broad ecosystem of industry-standard NICs and AI infrastructure platforms. Cisco optics are validated not only on Cisco hosts, but also across leading third-party Ethernet adapters to help ensure reliable operation in heterogeneous AI and cloud-scale deployments. Qualification testing includes electrical, optical, thermal, firmware, and protocol validation under real-world traffic conditions, including breakout operation such as 400G to 2×200G and 4×100G, as well as 800G to 2×400G and 4×200G architectures used in modern AI fabrics. Cisco transceivers are designed to interoperate with Cisco as well as standards-compliant third-party transceivers and NICs that comply with the same IEEE and MSA specifications. Testing also includes FEC interoperability and stress validation across operating environments. This comprehensive validation methodology helps provide predictable interoperability, stable link performance, and reduced deployment risk in modern AI and high-performance computing networks.

For a comprehensive list of validated optics-to-NIC interoperability combinations, please refer to the Cisco Transceiver Module Group (TMG) Compatibility Matrix: https://tmgmatrix.cisco.com/?npf=2227&npf=2003&npf=901&npf=903&npf=902.

Table 8.              QSFP112 DR4 SMF PAM4 breakout interoperability and link reach

Table 9.           QSFP112 MMF PAM4 breakout interoperability and link reach

Table 10.       QSFP112 FR4 SMF PAM4 interoperability and link reach

A comprehensive list of optics to optics and optics to host interoperability: https://tmgmatrix.cisco.com/.

Table 11.       Ordering information

Regulatory and standards compliance

Standards

●     IEEE 802.3ck

●     QSFP112 MSA

●     IEEE 802.3 (400GBASE-DR4) Requirements

●     IEEE 802.3 (400GBASE-VR4) Requirements

●     IEEE 802.3 (400GBASE-FR4) Requirements

●     GR-20-CORE: Generic Requirements for Optical Fiber and Optical Fiber Cable

●     GR-326-CORE: Generic Requirements for Single-Mode Optical Connectors and Jumper Assemblies

●     GR-468-CORE: Generic Requirements for Optoelectronic Devices Used in Telecommunications Equipment

●     GR-1435-CORE: Generic Requirements for Multifiber Optical Connectors

●     Common Management Specification (CMIS) Rev 4.0

●     IEEE Std 802.3 IEEE Standard for Ethernet

●     IEEE 802.3ba CL88

●     IEEE 802.3ck

●     IEEE 802.3cd CL136

●     IEEE 802.3cu CL140

Safety

●     Laser Class 1 21CFR-1040 LN#50

●     Laser Class 1 IEC60825-1

●     Compliance with North American (FCC/ICES), European (CENELEC), Japanese (VCCI), and Telcordia NEBS standards

●     GR-1089 EMC and Electrical Safety ‒ Generic Criteria for Network Telecommunications Equipment

●     EMI compliance on FCC Part 15 (30 MHz to 40 GHz) and CISPR32/CISPR22 (30 to 6000 MHz)

●     RFI compliance on EN/IEC 61000-4-3 and GR-1089-CORE (10k to 10 GHz)

●     ESD compliance on EN/IEC 61000-4-2 and GR-1089

●     Certification to IEC/EN 60825-1 +A2

●     RoHS 6 compliance

Table 12.       Laser class for QSFP112 modules

Additional information

For more information about Cisco 400G QSFP112 or other transceiver modules and cables, Visit https://www.cisco.com/en/US/products/hw/modules/ps5455/prod_module_series_home.html.