Start from the equipment, not the module

A transceiver module is bought for equipment, not for itself: the switch, router, or server it plugs into decides the rate, the form factor, and the software recognition, and a module that does not fit that equipment cannot serve, however good its specification looks on paper. Before choosing any module, write down the equipment's model, its port rate, its form factor, its software version, and its existing modules, because those five facts narrow the choice from hundreds of modules to a handful, and because a supplier who receives them can confirm compatibility for that equipment, rather than for a product family in general.

A buyer who starts from the module, instead, starts from the wrong end: a module that looks right on rate may fail on form factor, a module that fits may fail on wavelength, and a module that matches on all physical counts may be rejected by the equipment's software at boot. Starting from the equipment avoids all three failures, because the equipment's facts are fixed and the module must fit them, not the other way round, and because a choice made from fixed facts is a choice that can be confirmed in writing before ordering.

Match the rate to the port

The rate must match the equipment's port, because a module cannot make a port faster than it is, and a faster module in a slower port wastes the module's capacity while costing more than the slower module it replaces. A 10G port takes a 10G module, a 100G port takes a 100G module, and a 400G port takes a 400G module, and a buyer who orders a faster module for a slower port has paid for capacity the port cannot use, while a buyer who orders a slower module for a faster port has limited the link to the slower rate, and neither mistake is visible until the link is tested.

The families on this site run from 1.25G to 400G, and the category pages describe each family, so a buyer who knows the port rate can start from the right family and avoid the rate mistake entirely. Confirm the port rate from the equipment's documentation, not from the module's name, because a module's name may suggest a rate it does not carry, and because a port's rate is a fact of the equipment, not a guess from a product word.

Match the reach, with margin

The reach must match the link's distance, with margin, because a module whose reach exactly equals the link's distance leaves no room for routing, patching, measurement error, or future changes, and a link that measures longer than planned will fail. Measure the link's actual route, not its straight-line distance, because fiber routes through ducts, trays, and cabinets, and a route that looks short on a map may measure long in the building, and choose a reach comfortably longer than the measured distance, so the link has room for the realities of installation.

Confirm the reach for the exact fiber type in use, because a module's reach differs by fiber type, and a reach stated for one fiber type does not apply to another: a module that reaches 10km over single mode fiber may reach only a fraction of that over multimode fiber, and a buyer who orders on a reach stated for the wrong fiber type will order a module that cannot span their link, however right its rate appears.

Match the fiber type

The fiber type must match the installed fiber, because multimode fiber takes multimode modules and single mode fiber takes single mode modules, and a module for one cannot serve the other, however similar the rate appears. Check the installed fiber's type before ordering, from its marking, its documentation, or its installer, because the fiber type is a fact of the installation, not a choice the buyer makes at ordering time, and because a module ordered for the wrong fiber type cannot be adapted without replacing the fiber or the module.

Multimode fiber suits short links, where its lower cost and simpler connectors matter more than its shorter reach, and single mode fiber suits long links, where its longer reach matters more than its higher cost. A buyer who knows the installed fiber type can narrow the choice to modules for that type, and a buyer who does not know it must find out before ordering, because ordering without that fact is ordering blind, and a blind order is the most common cause of a module that arrives but does not serve.

Match the connector

The connector must match the installed connectors and the equipment's ports, because a module with the wrong connector cannot be plugged in without adapters, and adapters add loss, add failure points, and add cost, while reducing the link's reliability. Check the connector type on the installed fiber, on the patch panels, and on the equipment's ports, because all three must agree, and a module that matches two but not the third will require an adapter at the mismatched point, with the loss and failure that adapters bring.

LC, SC, and MPO connectors are the common types, but they are not interchangeable, and a buyer who orders by rate alone will often receive the wrong connector, because the connector is a separate choice from the rate, the reach, and the fiber type. Confirm the connector for the exact installation, in the inquiry, naming the equipment and the fiber, so the supplier can confirm the connector rather than assume it from the rate.

Do not choose by model name alone

A model name does not evidence a specification, and a model that looks similar to a known model may differ in reach, fiber type, or connector, so a buyer who chooses by model name alone is choosing by a word, not by a specification. Ask for the specification for the exact model, in writing, with the rate, the reach, the fiber type, and the connector, and compare that specification to the equipment's requirements, because a specification that matches on all four is a module that will serve, and a specification that mismatches on any one is a module that will not.

The representative pages on this site illustrate the point: some carry full specification tables, transcribed from their official product pages, while others carry only labelled title wording, because only titles are evidenced for them, and no specification table is built from any title. A buyer who reads a title as a specification will overestimate what the title evidences, and a buyer who asks for the specification, in writing, will receive the facts that matter.

Compatibility, and how it is stated

The company profile states compatibility with Huawei, Cisco, HP, H3C, Juniper and MikroTik, with attribution, on every model page, and that statement is the company profile's own statement, not a statement by any named equipment maker, and it does not imply authorisation, certification, or partnership with them. A general compatibility statement is a starting point, not a confirmation: a buyer who relies on it alone has relied on a general statement for a specific equipment, and a specific equipment needs a specific confirmation, for that equipment, in writing, before ordering.

Ask for a compatibility confirmation for your exact equipment, naming its model, its software version, and its existing modules, so the supplier can confirm that module for that equipment, rather than for a product family in general. A supplier who receives the equipment's facts can give a useful confirmation, and a supplier who receives only a product word can give only a general answer, which fits no equipment, and which a buyer should not order on.

What to confirm, before ordering

Before payment, confirm the specification for the exact model, the minimum order quantity for that model, the lead time with its meaning, the warranty terms, the payment and shipping terms, and the certificates that apply to your market, by name, with documents attached. Name the equipment, its port rate, the link distance, the fiber type, the connectors, the quantity, and the market, so the supplier can confirm for your installation, rather than for a general case, and so the confirmation you receive is the confirmation you can rely on.

A buyer who confirms all four matched counts — rate, reach, fiber type, connector — plus the trade terms, in writing, before payment, has done the work that prevents the common failures: the wrong rate, the short reach, the wrong fiber, the wrong connector, and the unwritten warranty. A buyer who skips that work has saved an hour and risked a shipment, and the hour saved is rarely worth the shipment risked.