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Small rectangular QSFP28 module with metallic finish and pull tab

STARTECH

STARTECH LOOPBACKPLUG100G 100G QSFP28 Loopback Module

SKU CH-MNMN-Q9AMF MPN LOOPBACKPLUG100G

A passive QSFP28 loopback module tests 100 Gbps network ports for continuity and fault isolation

  • Form factorQSFP28
  • Product typeQSFP28 Loopback Module
  • Supported standardsIEEE 802.3bj, IEEE 802.3by, MSA Compliant, 100GBASE, 40GBASE
  • Network cablingPassive Electrical Copper
  • Transfer speed100 Gbit/s
  • HighlightsPassive loopback testing, 100 ohm impedance, low jitter, por
  • 100 Gbps loopback testing validates high-speed links
  • Passive copper design requires no external power for port checks
  • MSA compliant QSFP28 form factor fits standard 100G switch ports
  • 100 ohm impedance with low jitter ensures accurate signal integrity verification
  • Compact 2.7 by 0.7 by 6.0 inch module enables dense rack installations

QSFP28 Loopback Module for 100 Gbps Testing

The StarTech LOOPBACKPLUG100G is a passive QSFP28 loopback module designed for network engineers and data-centre technicians who need to verify port continuity and isolate faults at line rate. It supports IEEE 802.3bj and IEEE 802.3by standards across 100GBASE, 40GBASE, 10GBASE and 1GBASE Ethernet links. The module provides a 100 ohm impedance with low jitter for reliable signal integrity checks.

Fits Directly into QSFP28 Ports Without External

The module plugs into any compliant QSFP28 cage on switches, routers, NICs or transceivers and draws no external power thanks to its passive copper design. It frees up test equipment by replacing active loopback generators for quick port bring-up, burn-in or troubleshooting cycles. MSA compliance ensures mechanical and electrical interoperability with standard hardware from multiple vendors.

No Cables, Software or Licences Required

The package contains only the loopback module itself; there are no cables, adapters, configuration utilities or licence keys to install or maintain. This keeps the test setup minimal and eliminates software compatibility concerns during hardware validation. The module is TAA compliant for projects that require approved country-of-origin sourcing.

How it compares

Measured against everything we stock in SFP & SFP+ Transceiver Modules, at today’s prices. Recalculated every night.

Price $60.99
Cheaper than about 68% of the 1,471 comparable items (median $138.99).

Specifications

Product
Brand nameStarTech
Model nameLOOPBACKPLUG100G
Part numberLOOPBACKPLUG100G
Product typeQSFP28 Loopback Module
Performance
Transfer speed100 Gbit/s
Connectivity
Supported standardsIEEE 802.3bj, IEEE 802.3by, MSA Compliant, 100GBASE, 40GBASE, 10GBASE, 1GBASE Ethernet
Network cablingPassive Electrical Copper
Size & build
Form factorQSFP28
Product dimensions2.7 inW × 0.7 inH × 6.0 inD
Product weight0.1 lb (0.05 kg)

Questions about this item

Does the passive copper design limit cable reach compared to active optical modules?

Yes, the module uses passive electrical copper media, so reach is limited to the host port's direct-attach copper specification rather than optical distances.

How much power does the module draw during continuous port testing?

The low power design consumes minimal power from the host QSFP28 port with no external supply needed.

Which host port standard must the switch or NIC already support for this module to function?

The host must provide a QSFP28 port compliant with IEEE 802.3bj or 802.3by for 100 Gbps operation.

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