Top FAQs About Fiber Patch Cables
Updated at Dec 18th 20241 min read
Fiber patch cables, or fiber optic patch cords, are vital in modern networks, ensuring reliable, high-speed data transmission. They connect devices using optical fibers and are available in various types, such as single-mode and multimode, to meet diverse application needs. Below are the most frequently asked questions (FAQs) about fiber patch cables, providing answers to help you better understand their types, jackets and applications.
FAQs on Data Center Fiber Patch Cable Definition, Types, and Connectors
Q1: What is a fiber patch cable?
A1: A fiber patch cable is a fiber optic cable with connectors at both ends to transmit optical signals between various fiber optic communication or network devices. These patch cables are typically used for short-distance connections in data centers or between racks to connect fiber optic distribution frames and equipment like switches, routers, and media converters. They enable efficient data transmission between devices. A fiber patch cable features a protective jacket to prevent fiber damage while supporting high-speed data transmission over longer distances.
Q2: What is the construction of a fiber patch cable?
A2:The construction of a fiber patch cable typically includes the following six components:
1. Core: Located at the center of the optical fiber, it is used for transmitting light waves.
2. Cladding: Located around the core, it confines the light waves within the core. The cladding is typically made of silica and sometimes plastic.
3. Coating: Located in the outermost layer of the fiber and serves to protect the bare fiber.
4. Buffer: Protect the fiber against bending effects.
5. Kevlar: Improve tensile strength and avoid tensile damage to fibers.
6. Jacket: Able to withstand high impacts and is isolated from temperature, humidity and dust. Conventional fire ratings are OFNR, OFNP, and LSZH.

Q3: What are the types of fiber patch cables?
A3: Fiber patch cables come in different types based on various factors, such as transmission distance, transmission type and cable structure. Here are the key types:
1. Transmission Distance: Fiber patch cables can be classified as single mode or multimode. Single mode cables (OS2) are used for long-distance communication, typically in backbone or wide-area networks. Multimode cables, suitable for shorter distances and further classified based on performance, such as OM1, OM2, OM3, and OM4, are each designed for specific distance and bandwidth needs.
2. Transmission Type: Fiber patch cables can be either an A-A crossover type, where both ends have the same connector, or an A-B straight-through type, where one end has an A-type connector and the other has a B-type connector. The choice of transmission type depends on the specific connection requirements between devices.
3. Cable Structure: Based on cable structure, fiber patch cables can be divided into simplex and duplex. Simplex cables use a single fiber for one-way data transmission and typically serve point-to-point connections. Duplex cables, containing two fibers, support bidirectional communication and are commonly used in network setups.

Q4: What are the connector types of fiber patch cables?
A4: Fiber patch cables have various connector types, each designed for specific applications. The most common connector types include:
LC | LC Short Boots | SC | LSH |
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Matching SFP/SFP+/XFP transceivers and LC adapters. | Mainly used in narrow cabling environments. | Matching GBIC/X2/XENPAK transceivers and SC adapters. | For telecommunication networks, fiber CATV, FTTH etc. |
ST | FC | MU | MTRJ |
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For datacom, FTTH, campuses, corporate networks etc. | For datacom, measurement equipment, lasers etc. | For data centers and enterprise networks. | High-density optical connections primarily for data transmission. |
Q5: What are the types of connector polishing for fiber patch cables?
A5: The type of polishing applied to a fiber plays a crucial role in the overall performance of a fiber optic system. Three primary polishing types are commonly used: Physical Contact (PC), Ultra Physical Contact (UPC), and Angled Physical Contact (APC).
PC: The fiber endface has a slight cylindrical curvature, aimed at eliminating or improving the air gap. Due to its relatively outdated performance, PC could not meet the higher demands for fiber connection quality in the modern telecommunications industry and has gradually been replaced by the superior-performing UPC.
UPC: Based on the PC's convex end-face properties, an extended polishing method produces lower (ORL) or reflectivity values and provides more reliable signals. It is mainly used for TV, telephony and data systems.
APC: The fiber endface is polished at an 8° angle for tighter connections and smaller air gaps. It is mainly used in FTTX, PON and other WDM systems.
For more information about fiber connector polish types, please refer to PC vs UPC vs APC Connector: Selecting the Right Fiber Connector Type.

FAQs on Data Center Fiber Patch Cable Features and Applications
Q1: What are the jackets of fiber patch cables?
A1: The jackets of fiber patch cables serve as protective coverings for the fibers inside, providing durability and safety in various environments. Common types of fiber patch cable jackets include:
PVC (Riser/OFNR): PVC jackets are commonly used for indoor applications. They provide reasonable protection against physical damage and are cost-effective, but they are unsuitable for high-temperature or outdoor environments because they release toxic gases when burned.
LSZH (Low Smoke Zero Halogen/LSOH): LSZH jackets are environmentally friendly and offer good flame-retardant properties, reducing toxic smoke and halogen emissions in the event of a fire. Though more expensive than PVC, they provide better fire resistance, making them ideal for safety-conscious indoor spaces like data centers, offices, and public buildings.
OFNP (Plenum): OFNP jackets, made from the highest fire-resistant material, are designed for use in plenum spaces, such as air ducts or air return pressurization system. They prevent flame spread and reduce smoke emissions. Due to their downward compatibility, OFNP patch cables can replace OFNR cables.
Q2: What are the applications of fiber optic cables?
A2: Fiber optic cables are used in various applications because they transmit data over long distances at high speeds with minimal signal loss. Common uses include:
Connecting optical modules and other optical transmission products. Single mode modules use single mode patch cables, while multimode modules can use corresponding patch cords based on the data rate. Here is a table that shows the speed and distance of single mode and multimode fiber patch cables:
OS2 | OM1&OM2 | OM3 | OM4&OM5 | |
Speed | 1/10/40/100/400G | 100M/1/10G | 10G | 40/100G |
Distance | Up to 200km | Up to 550m | Up to 330m | Up to 400m |
Connecting fiber optic transceivers, video optical terminals, and other enterprise network products.
Connecting to panels, enclosures, and chassis.
Connecting to MUX, OADM, and other WDM equipment.
Connect other devices, such as MTP boxes, ONU, measurement instruments, etc.
Q3: Why is a fiber optic cable much faster than copper cables?
A3: Fiber optic cables are faster than copper cables because they use light signals (photons) instead of electrical signals (electrons), allowing data to travel at nearly the speed of light without being hindered by resistance or capacitance; they experience less signal attenuation over long distances, are immune to electromagnetic interference, offer significantly higher bandwidth for modern high-speed communication needs, and avoid crosstalk issues that can degrade transmission quality in copper cables.
Q4: Can fiber patch cables be bent around a sharp corner?
A4: Fiber patch cables should generally not be bent around sharp corners, as this can cause damage to the fibers inside, leading to signal loss or breakage. However, it's recommended to use bend-insensitive fiber patch cables for environments where bending is unavoidable. These cables are specifically designed to withstand tighter bends without compromising performance.
ITU-T G.657 standards offer different levels of single mode fiber patch cables' bend-insensitivity: G.657.A1 fiber patch cables have a minimum bend radius of 10 mm, and G.657.A2 fiber patch cables at 7.5 mm. G.657.A2 is more bend-insensitive and suitable for installations requiring tighter bends. Depending on your specific needs, you can choose the appropriate standard to ensure optimal performance and flexibility for your installation environment.
Q5: How to properly maintain fiber patch cables?
A5: Proper maintenance of fiber patch cables is essential for ensuring optimal performance, preventing damage, and extending their lifespan. Here are some key practices to properly maintain fiber patch cables:
1. Do not over-bend and loop the fiber patch cables in use, as this will increase the attenuation of light in the transmission process. The bending radius must be greater than or equal to 150 mm when bending or coiling.
2. Protect the connector ferrule and its endface from bruising and contamination, and put on the dust cap immediately after disassembly.
3. When connecting the connectors of a fiber optic patch cord, they must be compatible with the type of flange (adapter) used. For example, an FC/PC-FC/APC patch cord requires that one connector connect to an FC/PC adapter while the other end connects to an FC/APC adapter.