Complement check
A-TX must match B-RX and B-TX must match A-RX.
Technical decisions
BiDi Wavelength Pairing Guide
A BiDi link is an A-side/B-side pair: each end must transmit inside the other end’s receive band.
BiDi modules use one fibre by separating transmit and receive wavelengths. A common shorthand such as 1270/1330 is incomplete unless the direction assigned to each endpoint is explicit.
Both ends must also share the same Ethernet/FC standard, modulation, reach class and receiver power window. Similar labels from different families are not automatically interchangeable.
MingApex coordinates China-based sourcing, OEM execution and independent quality-control evidence. It is not presented as the product manufacturer or an accredited laboratory; supplier identity, method and evidence boundary remain explicit.
01 / Decision inputs
Freeze the variables before comparing options
Freeze the directional pair before ordering either endpoint.
| Required input | What to record | How it changes the decision |
|---|---|---|
| Endpoint A | Host, port and required TX/RX wavelengths | Defines one half of the directional pair. |
| Endpoint B | Peer host, port and complementary wavelengths | Must invert the A-side direction. |
| Line standard | Rate, PMD and modulation | Both ends must implement the same signal. |
| Reach and loss | Fibre length, attenuation, connectors and margin | The pair must close both receive windows. |
| Coding | OEM identity and allowed EEPROM profile | Recognition remains endpoint-specific. |
| DOM | Reported TX/RX wavelengths, power and alarms | Telemetry must be interpreted per side. |
| Identification | A/B labels, colours, serials and packaging | Prevents field reversal. |
02 / Engineering comparison
Compare on measurable engineering criteria
Prove direction, power and identity at both ends.
Dual power budget
Calculate minimum and overload power in both directions.
Host recognition
Record coding, software, port mode and alarms per endpoint.
Traffic test
Run bidirectional traffic and error monitoring at the target rate.
Pair control
Lock A/B labels, serials and order quantities as matched sets.
03 / Product anchors
Live product examples for a controlled starting point
These live SKUs anchor the physical family. Suitability still depends on the documented host, fibre path and validation scope.
Live product page1G SFP 1310nm LX 10km LC TransceiverSingle-mode duplex-LC baselineLive product page10G SFP+ 1310nm LR 10km LC TransceiverSingle-mode LR referenceLive product page25G SFP28 1310nm LR 10km LC Transceiver25G FEC and lane referenceLive product page100G QSFP28 LR4 10km LC TransceiverFour-wavelength duplex-LC reference
A product page is a starting specification, not universal compatibility or lot-acceptance evidence.
04 / Decision patterns
Choose by evidence, not shorthand
Approve a pair, never an isolated wavelength label.
Preferred path
Approve when both complementary directions, receive windows, host identities and sustained traffic pass on the named route.
Conditional path
Use a mixed-vendor pair only after the exact A/B samples prove optical and host behaviour together.
Stop and redesign
Stop when one side’s TX/RX direction, receive band or part identity is ambiguous.
Revalidation trigger
Revalidate any wavelength, reach, host, software, coding, route-loss, supplier identity or revision change.
05 / Validation path
From requirement lock to approved order line
Capture both directions in one signed pairing record.
- 1
Freeze the requirement
Record the exact host, port, data rate, reach, fibre path and commercial scope for BiDi wavelength pairing.
- 2
Compare complete architectures
Include optics, fibre, connectors, power, cooling, software and operational constraints—not only unit price.
- 3
Define measurable acceptance
Set loss, telemetry, link, error, traffic and documentation criteria before selecting the sample.
- 4
Validate the named configuration
Test the serialized sample on the recorded setup and close deviations with an owner and deadline.
- 5
Bridge approval to production
Match the approved identity, revision, coding and critical attributes to the production lot and repeat order.
06 / Risk control
Failure modes that invalidate the decision
Same-side order
Two A-side units cannot form a complementary link.
Rate mismatch
Wavelengths pair but electrical standards differ.
One-way budget
Only one receiver window is calculated.
Field reversal
Uncontrolled labels swap A and B during installation.
07 / Evidence
Downloadable process references
08 / Buyer questions
Guide-specific questions
What does this guide decide?
Approval covers the recorded A/B part numbers, exact wavelengths, line rate, reach class, fibre route, host software, port mode, DOM behaviour and serialized samples.
What must the buyer provide?
Provide both host tuples, required rate/reach, fibre loss and the intended A-side/B-side part-number map.
When is the preferred path conditional?
Use a mixed-vendor pair only after the exact A/B samples prove optical and host behaviour together.
What must be revalidated?
Revalidate any wavelength, reach, host, software, coding, route-loss, supplier identity or revision change.
Connected authority paths
Continue through compatibility, quality and evidence
Controlled next step
Send both endpoints as one BiDi requirement.
We will map direction, receiver windows, host identity and pair labelling before quotation.