VIAVI TestCenter D2 1.6T 4-Port OSFP Appliance for AI Data Center and High-Speed Ethernet Testing

4-port OSFP1600 TestCenter appliance generating up to 6.4 Tbps of Layer 2-3 and AI workload test traffic from 100G to 1.6T.

MSA Interface: OSFP1600
Maximum test traffic: up to 6.4 Tbps
224 Gbps PAM4 mode port configurations: 1x1600G, 2x800G, 4x400G, and 8x200G
112 Gbps PAM4 mode port configurations: 1x800G, 2x400G, 4x200G and 8x100G

Datasheet

Overview

The VIAVI TestCenter D2 1.6T Appliance is a 4-port OSFP1600 test platform for validating AI data center fabrics and high-speed Ethernet infrastructure. It delivers up to 6.4 Tbps of test traffic and supports 1x1600G, 2x800G, 4x400G and 8x200G in 224 Gbps PAM4 mode (IEEE 802.3dj 1.6TBASE-R), as well as 1x800G, 2x400G, 4x200G and 8x100G in 112 Gbps PAM4 mode (IEEE 802.3ck and 802.3df 800GBASE-R). Auto-Negotiation and Link Training are supported for all speed modes. The appliance is offered in IHS and RHS variants.

AI workload emulation

The D2 emulates up to 128 GPUs and NICs per port and reproduces collective communication library (CCL) traffic patterns such as All-to-All and Ring-AllReduce. It can also emulate LLM training traffic models (Chat GPT, llama, DeepSeek, RestNet and AlexNet). CCL traffic can run alongside background traffic on the same port, and an Automatic Benchmark tool and CCL Wizard help set up test scenarios.

RoCEv2 and Ultra Ethernet

For RoCEv2, the appliance supports up to 16K Queue Pairs per port, RC, UD and UC transport modes, and DCQCN congestion control, with hardware-based per-flow ECN and port-level PFC across lossy and lossless fabrics. Optional Ultra Ethernet Transport (UET) licenses add stateful Transport and Link Layer emulation based on UEC 1.0, including Link Layer Retry, Credit-Based Flow Control, Link Layer error insertion and a UEC conformance test suite.

Layer 2-3 testing and automation

Beyond AI testing, the D2 runs standard TestCenter Layer 2-3 generation and analysis for routing, switching and data center protocols, including RFC 2544, 2889, 3918, 8239 and 6349 tests. Up to 255 appliances can be daisy-chained with self-calibrating inter-chassis timing. The TestCenter MCP Server, part of the VIAVI NITRO AI portfolio, lets users configure, run and analyze tests through natural language, alongside Command Sequencer visual programming and scripting.

Key Features

High-density OSFP test platform available in IHS and RHS variants, supporting speeds from 100G to 1.6T
Up to 6.4 Tbps of test traffic on a single 4-port appliance
1x1600G, 2x800G, 4x400G and 8x200G in 224 Gbps PAM4 mode per IEEE 802.3dj 1.6TBASE-R
1x800G, 2x400G, 4x200G and 8x100G in 112 Gbps PAM4 mode per IEEE 802.3ck and 802.3df 800GBASE-R
RS-FEC, Auto-Negotiation (AN) and Link Training (LT) in compliance with IEEE 802.3dj
GPU emulation of up to 128 GPUs and NICs per port
RoCEv2 with up to 16K Queue Pairs per port and DCQCN congestion control
CCL traffic patterns and LLM training traffic model emulation
UEC 1.0 Ultra Ethernet testing with stateful Transport and Link Layer emulation
UEC conformance test suite support
Comprehensive Layer 2/3, routing, switching and data center protocol validation
MACsec support on all ports
Compatible with optical transceivers, AOC, DAC and AEC interconnects
Layer-1 visibility with RS-FEC analysis and interconnect monitoring
Daisy chain of up to 255 appliances with ±20 ns synchronization
Per-port user reservation for up to 4 users per appliance
TestCenter MCP Server for natural-language test configuration, execution and analysis
Command Sequencer visual programming and GUI to Script automation

Specifications

General

MSA Interface	OSFP1600
Maximum test traffic	up to 6.4 Tbps
224 Gbps PAM4 mode port configurations	1x1600G, 2x800G, 4x400G, and 8x200G In compliance with IEEE 802.3dj 1.6TBASE-R
112 Gbps PAM4 mode port configurations	1x800G, 2x400G, 4x200G and 8x100G In compliance with IEEE 802.3ck and 802.3df 800GBASE-R
Line Clocking and Packet Time-Stamping	Stratum-3 rated oscillator is the default time source. Transmit line clock is at the precise nominal Ethernet rate ± < 1 PPM on initial shipment. Accurate to ± 4.6 PPM 15 years of operation. GPS, CDMA, IEEE 1588v2, NTP and TIA/EIA-95B-based external time sources are supported
Appliance Time Synchronization	Appliance delivers precise synchronization ± 20 ns VIAVI-patented self-calibrating inter-chassis timing chain using dedicated port on appliance
Daisy chain	up to 255 appliances For large density testing; synchronization via external GPS or CDMA network, IEEE 1588 or NTP, or TIA/EIA-95B timing inputs
Multi-User Support	Per-port (front panel port) user reservation up to 4 users per appliance

Environmental, Power and Physical

Operating Temperature Range	41° to 95°F (5° to 35°C) ambient temperature
Relative Humidity	20% to 80% relative humidity
Power Draw Range	2000 W to 3200 W at 180-240 VAC
Optical Power Support	Support for up to 40 W optical transceivers Stated for both IHS and RHS
Product Dimensions	30.5”D x 17.1”W x 3.5”H (43.4 cm x 8.9 cm x 77.47 cm) As printed in the datasheet; the metric values do not correspond in order to the imperial values
Product Weight	Unit installed weight: 53 lb. (24.0 kg)

Compliance

Safety Certifications	IEC 62368-1, UL 62368-1, CSA STD C22.2
EMC/Emissions	FCC PART 15, SUBPART B, ICES-003, EN55032 CLASS A, EN 61000-3-2, EN 61000-3-3 and EN55035
Regulatory Approvals	UL, Intertek, CE
Environmental Compliance	RoHS 2011/65/EU, WEEE 2012/19/EU

Layer 2-3 Generator and Analyzer

Number of Streams (Stats/Streams Tx/Rx)	1.6T: (4K/32K) 800G (4K/32K), 400G (16K/32K), 200G (8K/16K) Default Mode
Number of Paths / Raw Streamblocks	127 (1.6T/800G), 255 (400G/200G)
Frame Transmit Modes	Port based (rate per port), stream based (rate per stream), burst, timed, random frame size with unique seed and IMIX
Min/max Frame Size (w/CRC)	64 / 16383 bytes
Min/max Tx Rates	1 packet per 1.37 seconds to 101% of line rate
Real-time Tx Stream Adjustments	Change rate and frame length settings without stopping the generator or analyzer
Per-stream Statistics Analyzed in Real Time	Tx and Rx frame counts and rates; Tx and Rx Layer 1 byte counts and rates; FCS errors and rates; Min, Max, and Average Latency (32K streams); Real Time Dropped Frame count; Advance Sequence Tracking: Duplicate, reordered, late, and inordered
Priority Flow Control (PFC)	Support Priority Flow Control for 8 queues
Per-Port Statistics Analyzed in Real Time	Tx and Rx frame counts and rates; Tx and Rx Layer 1 byte counts and rates; PRBS errors; Data Integrity Check (DIC); FCS errors and rates
Transmit Timestamp Resolution	1600G: 2.5 ns Tx timestamp resolution With intra-chassis and inter-chassis synchronization
Supported Encapsulations	Layer 2: Ethernet II, 802.1Q, 802.1ad; Layer 3/4: IPv4, IPv6, TCP, UDP
Supported Tx Signature Capability	Fully compatible with VIAVI hardware; contains sequence number and highly accurate timestamp
Capture Buffer Size	1.28 MB per port (Max)
Capture Filters	User defined pattern definitions can logically combine 8 filters of up to 32 total bytes Patterns can be applied to start, filter (quality), or stop capture
Latency Modes	Benchmark tests support LIFO, LILO, FIFO or FILO latency calculation methods
Route Insertion Table (RIT) Entries Per Port	128K (1.6T,800G/400G/200G), 4-byte entries for dynamic label or random IP/MAC address assignments
RIT or List VFD Entries Per Stream	8 RIT insertions per stream (1.6T/800G/400G/200G); 4 VFD insertions per stream for all supported speeds
QoS	L2 - VLAN based 8 priority values; L3 - DSCP based 64 priority values

AI Testing

GPU/NIC Emulation	128 GPUs/NICs emulated per port
CCL Traffic Patterns	AlltoAll with PXN, All to ALL without PXN, RingAllReduce, Halving and Doubling, Dual Tree, RingReduceScatter, RingAllGather, Alternating Ring, Point to Point, Mixed Traffic Patterns and Background Traffic
LLM Model Emulation	Chat GPT, llama, DeepSeek, RestNet, and AlexNet to emulate training traffic models
RoCEv2 Configuration	RoCEv2 profile applied per port; Up to 16K Queue Pairs per port; RC, UD, and UC transport mode; DCQCN congestion control; Traffic mode - Continuous and Bursty; Full mesh, One-to-One, ALLtoALL; Bi-direction and Uni-direction traffic
UET Configuration	State full Link Layer; Link Layer Retry (LLR); Credit-Based Flow Control (CBFC); Link Layer Error insertion; State full Transport layer; Reliable ordered delivery (ROD); Reliable un-ordered delivery (RUD); High number of Fabric End Point (FEP); NSSC Congestion control; RCC Congestion Control; Packet trimming; Dynamic entropy change; Traffic mode - Continuous and Bursty; Full mesh, One-to-One, ALLtoALL; Bi-direction and Uni-direction traffic Requires optional UET software license
RoCEv2 Throughput	1.6T and 800G, 400G, 200G, 100G
UET Throughput	1.6T and 800G, 400G, 200G, 100G
Congestion Avoidance	Packet Trimming support; Multi pathing support
Congestion Control	ECN, PFC combination for lossy and lossless fabric; ECN detection, CNP notification; CNP interval; QoS priority for CNP notification; DCQCN; NSSC and RCC
Key Results and Statistics	JCT, Ideal JCT; Tail latency (P95/P99/P99.9); Algorithm bandwidth (algbw) and Bus bandwidth (busbw) based on JCT; CCL Traffic Chart algbw and busbw based on transmission time; Total Transmission Time, Total Training Time; Average, Max and Min Iteration Time; Throughput, packet loss, out of sequence packets, packet latency; ECN, CNP TX/RX; Receiver Window Size; Packet Rate; RTT; Retransmission Rate Available on Web and Windows GUI
Port Density for AI testing	up to 4x1.6T Ports / 8x800G Ports/16x400G Ports
UEC conformance test suite	over 50 test cases Initial coverage validates the Packet Delivery Sub-layer (PDS)
UET Load Balancing	ECMP, Adaptive Packet Spraying, Flowlet switching validation

Layer 1 Functionality

OSFP Interconnects	CR8, SR8, LR8, FR8, DR8 at multi-rate (1.6T/800G/400G/200G)
FEC	RS (544,514) FEC supported for all PAM4 speed modes
CMIS support	CMIS 5x and Coherent C-CMIS 1.2 support
224 Gbps PAM4 optical transceivers	1x1.6T: 1.6TBASE-SR8, 1.6TBASE-DR8, 1.6TBASE-FR8; 2x800G/4x400G/8x200G: 1.6TBASE-SR8, 1.6TBASE-DR8, 1.6TBASE-FR8, 1.6TBASE-2FR4
224 Gbps PAM4 copper cable	1x1.6T/2x800G/4x400G/8x200G: 1.6TBASE-CR8 Copper cable types include DAC, AEC and breakout cable; out of the box support
112 Gbps PAM4 optical transceivers	1x800G: 800GBASE-SR8, 800GBASE-DR8, and 800GBASE-FR8; 2x400G: 800GBASE-SR8, 800GBASE-2FR4, 400GBASE-DR4, 400GBASE-FR4; 4x200G: 800GBASE-SR8; 8x100G: 800GBASE-SR8
112 Gbps PAM4 copper cable	1x800G/2x400G/4x200G/8x100G: 800GBASE-CR8 Copper cable types include DAC, AEC and breakout cable; out of the box support
Auto-Negotiation / Link Training (AN/LT)	224G: 1x1.6T, 2x800G, 4x400G, 8x200G; 112G: 1x800G, 2x400G, 4x200G, 8x100G IEEE 802.3 compliant
Latency Compensation	Supported - eliminates inherent latency on the transmission path
Layer-1 Debug Tools and Features	Pre/Post FEC Codeword statistics, Tx Emphasis settings, Rx Eye view, FEC Counters, PRBS Gen/Check, Front-end L1 Summary Status, Xcvr MDIO access, PCS monitoring, Inter-sublayer Link Training (ILT)
Digital Optical Monitoring (DOM)	Yes - device status, electrical power, temperature, power class, laser power and numerous LOL and LOS threshold and alarm monitoring information
PRBS Pattern Support	PRBS-7Q, PRBS-9Q, PRBS-11Q, PRBS-13Q, PRBS-15Q, PRBS-19Q, PRBS-20Q, PRBS-23Q, PRBS-31Q PRBS-49Q, PRBS-58Q, and SSPRQ (Tx only) Pattern generation support and Rx-side statistics and analysis

Requirements

GUI workstation	Windows-based workstation with 10/100/1000 Mbps Ethernet NIC; mouse and color monitor required for GUI operation
Automation scripting	Linux- or Windows-based workstation
REST API support	Mac-, Linux, or Windows-based workstation

Specifications are taken from the manufacturer's documentation. See the datasheet for complete and current values.

Applications

AI data center back-end fabric testing
GPU, AI accelerator and AI NIC validation
RoCEv2 and congestion control validation
Ultra Ethernet Transport (UET) validation
Cloud computing and streaming services QoS validation
Data center ToR and EoR switches and fabrics
Terabit router testing
Chipset and silicon verification
Full Layer 2-3 network testing
Interoperability and conformance testing

Options & Accessories

Option	Description
D2-1600-OSFP-4-T1S	D2 4-Port OSFP1600 IHS 1.6T 800G 400G 200G Appliance — Hardware
D2-1600R-OSFP-4-T1S	D2 4-Port OSFP1600 RHS 1.6T 800G 400G 200G Appliance — Hardware
HWO-D2-1600-OSFP-4-200G	200G 224G PAM4 HW Speed Option D2-1600 OSFP IHS and RHS — Add-on after purchase of initial base package or bundle
HWO-D2-1600-OSFP-4-400G	400G 224G PAM4 HW Speed Option D2-1600 OSFP IHS and RHS — Add-on after purchase of initial base package or bundle
HWO-D2-1600-OSFP-4-800G	800G 224G PAM4 HW Speed Option D2-1600 OSFP IHS and RHS — Add-on after purchase of initial base package or bundle
HWO-D2-1600-OSFP-4-1600G	1.6T 224G PAM4 HW Speed Option D2-1600 OSFP IHS and RHS — Add-on after purchase of initial base package or bundle
HWO-D2-1600-OSFP-4-PORT	D2-1600-OSFP-4 Single Port Enablement IHS and RHS
D2-1600-OSFP-4-1600A	D2 4-Port OSFP1600 IHS 1.6T Only Bundle — Hardware bundle with speed options
D2-1600-OSFP-4-3000A	D2 4-Port OSFP1600 IHS 1.6T/800G/400G/200G Bundle — Hardware bundle with speed options
D2-1600R-OSFP-4-1600A	D2 4-Port OSFP1600 RHS 1.6T Only Bundle — Hardware bundle with speed options
D2-1600R-OSFP-4-3000A	D2 4-Port OSFP1600 RHS 1.6T/800G/400G/200G Bundle — Hardware bundle with speed options
SWO-D2-1600-OSFP-4-MACSEC	MACsec Software on D2-1600-OSFP-4 Appliance
HWO-D2-UET-200-32	UET Transport Layer and Link Layer for D2 200G 32 Port Suite
HWO-D2-UET-400-16	UET Transport Layer and Link Layer for D2 400G 16 Port Suite
HWO-D2-UET-800-8	UET Transport Layer and Link Layer for D2 800G 8 Port Suite
HWO-D2-UET-1600-4	UET Transport Layer and Link Layer for D2 1.6T 4 Port Suite
HWO-D2-UET-LL-200-32	UET Link Layer for D2 200G 32 Port Suite
HWO-D2-UET-LL-400-16	UET Link Layer for D2 400G 16 Port Suite
HWO-D2-UET-LL-800-8	UET Link Layer for D2 800G 8 Port Suite
HWO-D2-UET-LL-1600-4	UET Link Layer for D2 1.6T 4 Port Suite
HWO-D2-UET-600A	UET Transport Layer and Link Layer for D2 400G 16/200G 32 Port Suite
HWO-D2-UET-1000A	UET Transport Layer and Link Layer for D2 800G 8/200G 32 Port Suite
HWO-D2-UET-1200A	UET Transport Layer and Link Layer for D2 800G 8/400G 16 Port Suite
HWO-D2-UET-1800A	UET Transport Layer and Link Layer for D2 1.6T 4/200G 32 Port Suite
HWO-D2-UET-2000A	UET Transport Layer and Link Layer for D2 1.6T 4/400G 16 Port Suite
HWO-D2-UET-2400A	UET Transport Layer and Link Layer for D2 1.6T 4/800G 8 Port Suite
HWO-D2-UET-2800A	UET Transport Layer and Link Layer for D2 1.6T 4/800G 8/400G 16 Port Suite
HWO-D2-UET-3000A	UET Transport Layer and Link Layer for D2 1.6T 4/800G 8/400G 16/200G 32 Port Suite
AON-D2-UET-3000A	AION UET Transport Layer and Link Layer for D2 1.6T 4/800G 8/400G 16/200G 32 Bundle
HWO-D2-UET-LL-600A	UET Link Layer for D2 400G 16/200G 32 Port Suite
HWO-D2-UET-LL-1000A	UET Link Layer for D2 800G 8/200G 32 Port Suite
HWO-D2-UET-LL-1200A	UET Link Layer for D2 800G 8/400G 16 Port Suite
HWO-D2-UET-LL-1800A	UET Link Layer for D2 1.6T 4/200G 32 Port Suite
HWO-D2-UET-LL-2000A	UET Link Layer for D2 1.6T 4/400G 16 Port Suite
HWO-D2-UET-LL-2400A	UET Link Layer for D2 1.6T 4/800G 8 Port Suite
HWO-D2-UET-LL-2800A	UET Link Layer for D2 1.6T 4/800G 8/400G 16 Port Suite
HWO-D2-UET-LL-3000A	UET Link Layer for D2 1.6T 4/800G 8/400G 16/200G 32 Port Suite
AON-D2-UET-LL-3000A	AION UET Link Layer for D2 1.6T 4/800G 8/400G 16/200G 32 Bundle
HWO-D2-4-ROCE-ECN-200-32	RoCE ECN-1600G for D2 32X 200G ports total per test module
HWO-D2-4-ROCE-ECN-400-16	RoCE ECN-1600G for D2 16X 400G ports total per test module
HWO-D2-4-ROCE-ECN-800-8	RoCE ECN-1600G for D2 8X 800G ports total per test module
HWO-D2-4-ROCE-ECN-1600-4	RoCE ECN-1600G for D2 4X 1600G ports total per test module
HWO-D2-4-ROCE-ECN-2400A	RoCE ECN 1.6T/800G Suite for D2 — 4 X 1.6T or 8 X 800G
HWO-D2-4-ROCE-ECN-2800A	RoCE ECN 1.6T/800G/400G Suite for D2 — 4 X 1.6T or 8 X 800G or 16 X 400G
HWO-D2-4-ROCE-ECN-3000A	RoCE ECN 1.6T/800G/400G/200G Suite for D2 — 4 X 1.6T or 8 X 800G or 16 X 400G or 32 X 200G
HWO-D2-4-CCL-4	CCL for D2-1600-OSFP-4 — All speeds supported