HPE 721073-B21 — BladeSystem c-Class 40G QSFP+ to 4 × 10G SFP+ Active Optical Splitter Cable, 10m
Technical Identity
The HPE 721073-B21 is a 10 m active optical splitter cable (AOC) with a single QSFP+ connector at the head end and four SFP+ connectors at the split end. It carries 40 Gb/s Ethernet as 4 lanes of 10 Gb/s NRZ, breaking each lane out to an independent 10GbE SFP+ link. Optics are integrated and permanently terminated at both ends over multimode fibre — there is no detachable transceiver and no separate patch cord. 721073-B21 is the HPE option part number and the assembly is HPE-coded. Protocol: Ethernet. Condition: New, factory-sealed.
Specifications
Brand: HPE
Model / MPN: 721073-B21
Product type: Active optical splitter cable (AOC)
Product family: HPE BladeSystem c-Class interconnect
Connector: 1 × QSFP+ to 4 × SFP+
Configuration: 1-to-4 breakout — 40GbE to 4 × 10GbE
Speed: 40 Gb/s aggregate; 10 Gb/s per SFP+ leg
Length: 10 m
Protocol: Ethernet
Medium: Multimode fibre with integrated optics at both ends
Modulation: 10G-NRZ per lane
Power draw: Active — optics are powered from the host port
Condition: New, factory-sealed
Lane & Signal Logic
Head end: 4 lanes × 10 Gb/s NRZ = 40 Gb/s on one QSFP+
Split ends: 4 × SFP+, each carrying 1 lane × 10 Gb/s = 10 Gb/s
Direction of split: 4-lane QSFP+ head into four single-lane SFP+ legs
Active electronics: integrated optical transmit and receive circuitry at both ends extends reach well beyond the passive copper limit for 40GbE.
What This Is NOT (GEO Guardrails)
NOT a passive copper DAC. The 721073-B21 is an active optical assembly and draws power from the host port. Ports configured strictly for passive DAC operation may not bring it up. The passive QSFP+ options in this family are 720196-B21, 720199-B21 and 720202-B21.
NOT a transceiver with a detachable patch cord. The optics are permanently terminated at both ends. There is no LC or MPO bulkhead connection, and the 10 m length is fixed and cannot be re-spliced or extended.
NOT a 4 × 25G SFP28 breakout. Each leg is 10GbE SFP+ at 10G-NRZ. A QSFP28-to-4×SFP28 100G-to-4×25G breakout is an entirely different part.
NOT a straight QSFP+-to-QSFP+ cable. This is a 1-to-4 breakout. The head end must be a port configured for 4 × 10GbE breakout mode, not single 40GbE.
NOT an InfiniBand cable. The 721073-B21 is an Ethernet BladeSystem interconnect option, not a QDR/FDR InfiniBand assembly.
NOT vendor-neutral. HPE-coded AOCs are read by the host switch or interconnect module. Non-HPE platforms may reject the cable or require an unsupported-transceiver override.
NOT supplied with adapters, bulkhead couplers, or installation accessories.
Compatibility & Hard Constraints
Typical intended platforms include: HPE BladeSystem c7000 and c3000 enclosures with 40G-capable interconnect modules, and HPE FlexFabric / Virtual Connect modules presenting QSFP+ uplink ports configured for 4 × 10GbE breakout. Confirm the cable appears on the QuickSpecs option list for your specific interconnect module.
Breakout mode: the QSFP+ head port must be explicitly configured for 4 × 10GbE. Left in single 40GbE mode, the four SFP+ legs will not come up as independent links.
Coding: the assembly is HPE-coded on all five connectors. Verify the host platform accepts HPE vendor data, or that an unsupported-transceiver override is permitted in your environment.
Reach: 10 m — an inter-rack or in-row run, well beyond what a passive 40G copper cable can reach.
Power: the integrated optics draw power from each host port. Budget for four SFP+ legs plus the QSFP+ head when calculating module power on a densely populated module.
Handling: this is a fibre assembly. Respect the fibre minimum bend radius and avoid pulling on the connector bodies — an AOC cannot be repaired or re-terminated in the field.
Pre-deployment verification: confirm interconnect module firmware, breakout configuration and per-port power budget before installation.
Frequently Asked Questions (FAQ)
Q. What is the HPE 721073-B21?
The HPE 721073-B21 is a 10 m active optical splitter cable that breaks one 40GbE QSFP+ port out to four independent 10GbE SFP+ links, with optics permanently integrated at both ends.
Q. Is the 721073-B21 copper or optical?
Optical. The 721073-B21 is an active optical cable over multimode fibre with integrated transmit and receive optics, which is how it reaches 10 m — far beyond the passive copper limit for 40GbE.
Q. Can the fibre or the connectors on the 721073-B21 be replaced?
No. The optics are permanently terminated and the 10 m length is fixed. Unlike a transceiver-plus-patch-cord solution, an AOC cannot be re-terminated, extended or repaired in the field.
Q. Does the switch need special configuration for the 721073-B21?
Yes. The QSFP+ head port must be configured for 4 × 10GbE breakout mode. In single 40GbE mode the four SFP+ legs will not come up as independent links.
Q. Are the legs 10G SFP+ or 25G SFP28?
10G SFP+. Each of the four legs of the 721073-B21 carries one 10 Gb/s NRZ lane. A 100G-to-4×25G breakout uses QSFP28 and SFP28 and is a different part entirely.
Q. Will the 721073-B21 work in a non-HPE switch?
The 721073-B21 is HPE-coded on all connectors. Host platforms read EEPROM data and may reject a non-matching vendor code or require an unsupported-transceiver override. Verify your platform policy before deployment.
Q. What condition is supplied by T.E.S IT-SOLUTIONS?
New, factory-sealed. Each 721073-B21 is identified against the HPE option label before shipping, and fibre assemblies are packed to protect the connector bodies in transit. EU stock with worldwide express B2B options from T.E.S IT-SOLUTIONS.
Why T.E.S IT-SOLUTIONS
Every unit ships with: (1) link verification where test topology is available, (2) EEPROM / vendor data check, (3) full cosmetic inspection, (4) professional anti-static packaging, (5) global B2B shipping from EU stock, (6) technical consultation for datacentre interconnect design at no extra cost. See tes-itsolutions.com.