An MPO female to female patch cord has unpinned connectors at both ends, so it plugs into pinned ports such as transceivers and the pinned side of a cassette or adapter. Order it by fibre count, Type A, B or C, polish, length and jacket. Use it only where both mating connectors carry pins; if either far side is unpinned, that end must be male.
What a female to female MPO patch cord is
An MPO female to female patch cord has a plug with two empty guide holes at each end and no pins. The pins live on the connector it mates with, so the cord is the right choice when both of the places it plugs into are pinned. That describes most optical transceiver ports and many cassette and module fronts, which is why female to female is the most requested gender for short MPO cords.
The terms pinned and unpinned describe the same thing as male and female. Pinned is male. Unpinned is female. Suppliers use both vocabularies, so write both on a purchase line if your team uses one and your supplier the other. The overall family of cords is on the MTP MPO patch cords page, and the connector itself is described in the MPO connector guide.
Pinned and unpinned: the three gender combinations
| Cord | Each end plugs into | Typical place it is used |
|---|---|---|
| Female to female | A pinned connector at both ends | Transceiver to transceiver; transceiver to a pinned cassette or adapter port |
| Male to female | A pinned end on one side, an unpinned end on the other | A pinned cassette or port on one side, and an unpinned trunk end behind an adapter on the other |
| Male to male | An unpinned connector at both ends | Joining two unpinned trunk ends through an adapter, and some test setups |
A mated pair needs pins on exactly one side. Two pinned connectors cannot seat. Two unpinned connectors will latch in an adapter, but nothing aligns the fibre arrays, and loss becomes high and unstable.
Work out the gender at each end
Decide the gender one interface at a time, not for the cord as a whole.
- List the two things the cord will plug into, one per end.
- For each, find out whether the connector facing the cord is pinned. Transceiver ports carry pins. For cassettes, panels and modules, read the datasheet, because makers differ.
- If the facing connector is pinned, that end of the cord is female. If it is unpinned, that end is male.
- If the cord goes through an adapter, count the connector on the far side of the adapter, not the adapter itself, since an adapter has no pins.
Two female ends are correct only when both answers at step 3 are female. Gender is fixed when many MPO plugs are built, and MTP housings can be reworked to change the pins, but only with the proper tool and followed by cleaning, inspection and retest. Order the gender you need instead of planning to change it on site.
Type A, B and C female to female cords
The type is the fibre routing and key orientation of the cord. This table covers which type to order; the theory is in the MPO polarity guide.
| Type | Key orientation, end to end | 12-fibre routing | When a female to female cord of this type is ordered |
|---|---|---|---|
| Type A | Key-up to key-down | Straight through | The straight cord at one end of a Method A channel, with a Type B cord at the other |
| Type B | Key-up to key-up | Fully reversed | Transceiver to transceiver, and both ends of a Method B channel |
| Type C | Key-up to key-down | Adjacent pairs flipped | Duplex designs on Method C only; not for parallel optics |
A Type B female to female cord is what most buyers want when they plug one parallel transceiver directly into another. Match the type to the method written on the channel drawing, not to the label on the trunk alone, and ask for the type to be marked at each end.
12-fibre and 24-fibre cords
| Fibre count | Connector | Used with | Note |
|---|---|---|---|
| 12 | MPO-12 | Four-lane optics such as 40GBASE-SR4, 100GBASE-SR4 and 400GBASE-DR4, and Base-12 panels | Four-lane optics use 8 of the 12 fibres; the middle four stay idle |
| 24 | MPO-24, two rows of 12 | High-density panel-to-panel links, and older 100GBASE-SR10 optics | Type B reverses all 24 positions, so position 1 meets position 24 |
| 16 | MPO-16 | Eight-lane optics at 400G and 800G | Offset key, so it does not mate with a 12-fibre or 24-fibre connector |
Fibre count and gender are independent. A 24-fibre cord also comes in female and male forms, so state both on the line. Single-mode cords are polished at an angle and multimode cords flat, and the polish must match everything else in the channel. Single-mode orders are covered separately in the UPC vs APC guide, and the cord pairs with OM3 or OM4 fibre for multimode links, as with the MTP OM4 patch cords Radix makes.
When a female to female MPO patch cord is the right cord
Female to female is correct in these cases:
- Two parallel transceivers connected directly, switch port to switch port or switch to server.
- A transceiver connected to a cassette, module or adapter panel that presents pinned connectors.
- A pinned test instrument port connected to a pinned panel port.
It is the wrong cord in these cases:
- The cord plugs through an adapter into an unpinned trunk end. That end needs to be male.
- The fibre counts differ, such as an MPO-12 cord for an MPO-16 port.
- The polish differs, such as a flat multimode cord for an angled single-mode port.
- The type does not match the polarity method of the channel, even though the connectors fit.
A cord with the wrong gender fits poorly or not at all, while one with the wrong type fits perfectly and still fails to bring the link up. Check both before the order goes out.
What to send us for a quote
Send one line per configuration with:
- Fibre count and fibre type: OS2, OM3, OM4 or OM5.
- Connector: MPO or MTP, and gender written out as female (unpinned) at each end.
- Polish: flat or angled, matched to the equipment.
- Type A, B or C, and the polarity method of the channel.
- Length, with the tolerance, measured along the route.
- Jacket rating and colour, round or flat construction, and outer diameter limit.
- Label text at each end, and boot style if push-pull is wanted.
- Test report format and the maximum insertion loss per mated pair.
- Quantity per line.
A list of the transceivers or cassettes at each end, with part numbers, lets the gender be checked against the hardware before manufacture. Send the list through the request a quote page.
Questions buyers ask
What does female to female mean on an MPO patch cord?
It means the cord has unpinned connectors at both ends, with guide holes and no pins. It mates with connectors that carry pins. Female is the same as unpinned, and male is the same as pinned.
Which MPO gender do transceivers need?
Transceiver ports carry the guide pins, so a cord that plugs into one needs a female (unpinned) end. A cord between two transceivers is female to female.
Can I join two female MPO cords with an adapter?
Physically they will latch, but nothing holds the fibres in alignment, so loss is high and varies from one mating to the next. A pinned connector has to sit on one side of every mated pair.
Which type is a female to female cord for two transceivers?
Usually Type B, which reverses the fibres end to end so transmit meets receive. Confirm against the optic datasheet and the channel method before ordering.
Does a 24-fibre cord come in the same genders as a 12-fibre cord?
Yes. MPO-24 cords are made male or female, and the gender follows the connector they mate with. State it at each end on the order.
Can the gender of an MPO cord be changed after it is made?
On many plugs it is fixed at manufacture. MTP housings can be reworked to change the pins with the right tool, but the connector then has to be cleaned, inspected and retested. Ordering the right gender is simpler.