Tag Archives: patch cord

Backbone Cabling vs Horizontal Cabling


Computer networks require complicated and specific cabling, particularly in business or academic settings. The cables used in cabling the networks must be made from certain materials. Backbone cabling and horizontal cabling are two main cabling methods used in today’s structured cabling system and neither is dispensable. In order to meet different connection needs, cables used in backbone cabling and horizontal cabling also have many differences from each other. So what’s the difference between them? Knowledge of backbone cabling and horizontal cabling will be introduced in this article.

Structured Cabling System Basics

To understand backbone cabling and horizontal cabling, let’s understand the six subsystems of structured cabling firstly. These six subsystems are often found throughout a building and are connected together so that various types of data can be transmitted consistently and securely (as shown in the figure below).

Structured Cabling System

  • Entrance Facility: This room is where both public and private network service cables communicate with the outside world.
  • Equipment Room:  A room with equipment that serves the users inside the building.
  • Telecommunications Room: This room contains the telecommunications equipment that connects the backbone and horizontal cabling subsystems.
  • Backbone Cabling: A system of cabling that connects the entrance facilities, equipment rooms, and telecommunications rooms.
  • Horizontal Cabling: The system of cabling that connects telecommunications rooms to individual outlets or work areas on the floor.
  • Work Area Components: These connect end-user equipment to outlets of the horizontal cabling system.

Backbone Cabling

The backbone cabling is also called vertical cabling or wiring. It provides interconnection between telecommunication rooms, equipment rooms, and entrance facilities. These backbone cablings typically are done from floor to floor to floor. When setting up backbone cabling, several types of media can be used: unshielded twisted-pair (UTP) cable, shielded twisted-pair (STP) cable, patch cord, or coaxial cable. Equipment should be connected by cables of no more than 30 meters (98 feet).

Backbone Cabling

With the emerge of Gigabit Ethernet and 10 Gigabit Ethernet, fiber optic cable is the most appropriate choice for backbone cabling since they provide much higher bandwidth than traditional Cat5, Cat6 or even Cat7 twisted pair copper cables. Another advantage of fiber is that fibers can run much longer distance than copper cable, which makes them especially attractive for backbone cabling.

Horizontal Cabling

The horizontal cabling system extends from the work area’s telecommunications information outlet to the telecommunications room (TR) or telecommunications enclosure (TE). As shown in the figure below, horizontal cabling is usually installed in a star topology that connects each work area to the telecommunications room. It includes the telecommunications outlet, an optional consolidation point, horizontal cable, mechanical terminations and patch cords (or jumpers) located in the TR or TE.

Horizontal Cabling

Four-pair 100-ohm unshielded twisted-pair (UTP) cabling (Cat5 or Cat5e cabling) is usually recommended for new installations because it supports both voice and high-speed data transmission. To comply with EIA/TIA wiring standards, individual cables should be limited to 90 meters in length between the outlet in the work area and the patch panels in the telecommunications room. Patch cords for connecting the patch panel to hubs and switches in the telecommunications room should be no longer than 6 meters total distance. Cables connecting users’ computers to outlets should be limited to 3 meters in length.

Backbone Cabling  vs Horizontal Cabling

Although the same types of cables are used for both backbone and horizontal cabling, since backbone cabling typically passes through from floor to floor, the cables used for backbone cabling have the very different requirement from the horizontal cablings. Backbone cables must meet particular fire-rating specifications, typically OFNR (Optical Fiber Non-Conductive Riser) rated. If the backbone cable passes through plenum area (spaces in the building used for air return in air conditioning), the cable must be OFNP (Optical Fiber Non-conductive Plenum) rated. Besides, since backbone cables need to have enough strength to support its own weight, cable strength for backbone cables is also different from horizontal cables. And unlike horizontal cables, backbone cables must be secured correctly.


As two important parts of structured cabling, both backbone cabling and horizontal cabling play an irreplaceable role. And due to the different cabling environment, backbone cables and horizontal cables may have different specifications. FS.COM provides both Cat5, Cat6 or Cat7 UTP or STP copper cables and OFNR or OFNP multimode or single-mode fiber patch cables for backbone cabling and horizontal cabling. For more information about the backbone cabling and horizontal cabling solutions or other cabling solutions, please contact us via sales@fs.com.


Fiber Patch Cord Power Loss Measurement


Multi-mode patch cord optical loss power measurement is performed using the steps described in ANSI/TIA-526-14,method A. The patch cord is substituted for the cable plant. Because patch cords are typically no longer than 5 m, the loss for the optical fiber is negligible and testing can be performed at 850 nm or 1300 nm. The loss measured in this test is the loss for the patch cord connector pair. ANSI/TIA-568-C.3 states that the maximum loss for a connector pair is 0.75 db.

After setting up the test equipment as described in ANSI/TIA-526-14, method A, clean and inspect the connectors at the ends of the fiber patch cord to be tested. Verify that your test jumpers have the same optical fiber type and connectors as the patch cords you are going to test. The ANSI/TIA-526-14 being used for testing. Ensure that there are no sharp bends in the test jumpers or patch cords during testing.

Because both patch cord connectors are easily accessible, optical power loss should be measured in both directions. The loss for the patch cord is the average of the two measurements. If the loss for the patch cord exceeds 0.75dB in either direction, the patch cord needs to be repaired or replaced.

Connector insertion loss measurement isolates the loss of a single connector on a cable assembly. It may be referred to as connector loss. Many time cable assemblies are shipped from the manufacturer with the insertion loss for each connector listed on the packaging. The package shown in Figure 33.37 contains a duplex multi-mode patch cord. In the upper-left corner of the package, a label lists the insertion loss measurements for each connector.

Connector test jumper 1 as shown earlier in Figure 33.31. Record the optical power displayed by the optical power meter. This number is the reference power measurement. This number is typically around -20dBm with a 62.5/125μm multimode optical fiber and -23.5dBm with a 50/125μm multimode optical fiber. These numbers can vary from OLTS to OLTS. The following are 62.5/125μm and 50/125μm multimode fiber from fiberstore, picture is below:

SC-SC Multi mode

SC-SC Plenum Duplex 62.5/125 Multi-mode Fiber Patch Cable, with SC to SC termination, this fiber optic patch cable is specificially designed for ethernet, multimedia, or communication applications. The SC connector features a push-pull locking system. The plenum rating provides the fire protection required to run this cable within walls and air plenums without using conduit. The patented injection molding process provides each connection greater durability in resisting pulls, strains and impacts from cabling installs.


ST Fiber Cable connector has a bayonet-style housing and a long spring-loaded ferrule hold the fiber. They are available in both multi-mode or single mode versions. Horizontally mounted simplex and duplex adapters are available with metal or plastic housing.