Arista QSFP-100G-SR4: 100GBASE-SR4 QSFP28 Transceiver for Short-Reach Data Center Links
The Arista
QSFP-100G-SR4 is the workhorse 100 Gigabit short-reach optic for the data center. Compliant with IEEE 802.3bm
100GBASE-SR4, it delivers a full 100Gbps over parallel multimode fiber using four 25Gbps lanes at 850nm, terminated in a standard MPO-12 connector — reaching up to 70m on OM3 and 100m on OM4. It is the default, most cost-effective choice for leaf-spine fabric links, 100G top-of-rack uplinks, and switch-to-switch runs that stay inside a single data hall. As part of Arista’s
QSFP28 optics line, it drops into any Arista 100G QSFP28 port and runs natively under EOS.
At a Glance
- Standard: 100GBASE-SR4 (IEEE 802.3bm), QSFP28 / SFF-8636
- Data rate: 100Gbps aggregate (4 x 25.78Gbps lanes)
- Wavelength: 850nm VCSEL over parallel multimode fiber
- Reach: 70m on OM3, 100m on OM4
- Connector: MPO-12 / MTP (8 fibers active)
- Media: OM3 / OM4 multimode fiber
- Max power: 3.5W
- Diagnostics: Digital Optical Monitoring (DOM) via I2C
- Operating range: 0°C to 70°C (commercial)
Why network teams standardize on the QSFP-100G-SR4 for in-row 100G:
- Lowest cost per 100G link inside the row: SR4 over existing MPO multimode trunks is the cheapest way to bring up 100G when distances stay under 100m — no single-mode plant required.
- Reuses 40G MPO cabling: The same MPO-12 OM4 ribbon that carried 40GBASE-SR4 carries 100GBASE-SR4, so 40G-to-100G migration needs no recabling.
- Native Arista EOS support: Arista-coded for clean recognition and full DOM telemetry under EOS — no compatibility flags or unsupported-optic warnings.
- Universal QSFP28 fit: Works in the 100G ports across the 7050X3, 7060X, 7260X3, and 7280R switching lines.
- Low power, high density: 3.5W maximum keeps thermal and power budgets in check across fully-populated 32- and 48-port 100G platforms.
100GBASE-SR4 Optical Specifications
The QSFP-100G-SR4 transmits four independent 25Gbps channels at 850nm across eight strands of multimode fiber (four transmit, four receive) on an MPO-12 interface. It is fully compliant with the QSFP28 MSA and IEEE 802.3bm, with forward error correction handled by the host switch.
- Four-lane parallel optics: 4 x 25.78Gbps NRZ lanes aggregate to 103.125Gbps line rate (100GbE).
- OM3 / OM4 reach: 70m over OM3 and 100m over OM4 parallel multimode fiber.
- MPO-12 termination: Pairs with standard MPO/MTP OM4 trunk cabling and cassettes.
- Digital Optical Monitoring: Real-time per-lane temperature, voltage, bias, and Tx/Rx optical power readable in EOS.
- Hot-swappable QSFP28: Field-installable with no switch downtime.
Compatible Arista Platforms
The QSFP-100G-SR4 operates in the 100G QSFP28 ports found across Arista’s data center switching portfolio. Common pairings include:
Where the QSFP-100G-SR4 Fits
Three deployment patterns where SR4 is the right 100G optic.
Leaf-Spine Fabric Inside the Row
100G links between leaf and spine switches within the same row or adjacent racks, where OM4 trunk runs stay under 100m. SR4 is the lowest-cost optic for this distance and the most common 100G fabric build.
100G Top-of-Rack Uplinks
Uplinking 7050X3 or 7060X top-of-rack switches into a 100G aggregation layer over structured multimode cabling, with full DOM visibility for link health monitoring.
40G-to-100G Migration
Upgrading an existing 40GBASE-SR4 deployment to 100G. Because SR4 reuses the same MPO-12 multimode plant, the migration is a transceiver swap with no recabling.
QSFP-100G-SR4 vs LR4: Choosing the Right 100G Optic
The three most common Arista 100G QSFP28 optics differ by fiber type and reach. Pick by the distance and cabling you already have.
- QSFP-100G-SR4 (this module): Multimode (OM3/OM4), MPO-12, 850nm, up to 100m. Lowest cost; for in-row and in-rack links.
- QSFP-100G-LR4: Single-mode, duplex LC, 1310nm, up to 10km. For building-to-building and long campus runs.
Rule of thumb: if your run is multimode and under 100m, choose SR4; if you need to cross to single-mode fiber, step up to LR4 (10km).
Coding and Interoperability
BrightStar’s QSFP-100G-SR4 modules are Arista-coded and tested for clean recognition under Arista EOS, including full Digital Optical Monitoring. Because 100GBASE-SR4 is an IEEE 802.3bm standard, an SR4 module interoperates with any other standards-compliant 100GBASE-SR4 port on the far end of the link, regardless of switch vendor.
Frequently Asked Questions
What is the Arista QSFP-100G-SR4?
It is a 100 Gigabit Ethernet QSFP28 optical transceiver that implements the 100GBASE-SR4 standard, sending 100Gbps over four 25Gbps lanes at 850nm across parallel multimode fiber with an MPO-12 connector.
What is the maximum distance of the QSFP-100G-SR4?
Up to 70 meters over OM3 multimode fiber and up to 100 meters over OM4 multimode fiber.
What fiber and connector does it use?
Parallel multimode fiber (OM3 or OM4) terminated in a standard MPO-12 / MTP connector, using eight fibers (four transmit, four receive).
Does the QSFP-100G-SR4 support 4x25G breakout?
No. SR4 is a single 100G link over parallel fiber, not a breakout optic. To break a 100G QSFP28 port into 4x25G, use SFP28 transceivers or a QSFP28-to-4xSFP28 breakout cable instead.
Is the QSFP-100G-SR4 compatible with Arista EOS?
Yes. These modules are Arista-coded for native recognition and full DOM telemetry under EOS, with no unsupported-optic warnings.
Buy the Arista QSFP-100G-SR4 from BrightStar Systems
BrightStar Systems stocks new, refurbished, and used Arista QSFP-100G-SR4 transceivers, each tested for compliant 100GBASE-SR4 operation under Arista EOS before it ships and backed by our warranty. Volume pricing and matched MPO-12 OM4 cabling are available —
request a quote for current stock and lead time.
