40G Structured Cabling Solutions

Posted on by FS.COM

With speeds in the data center now increasing from 10G to 40G and eventually to 100G, different optical technologies and cabling infrastructures are required. Unstructured cabling such as a point to point connectivity method can’t satisfy our needs any more. Mistakes may always appear in an unorganized messy cabling infrastructure. Trying to remove a single cable from a large tangled mess can cause stress on the other cables. This stress can lead to network and channel errors in the hardware that are very difficult to trace. However, a structured cabling system provides a cabling infrastructure that delivers predictable performance, which provides redundancy and future proofs the usability of the cabling system. This article introduces the cable requirements for 40G structured cabling solutions.

point to point

What Is Structured Cabling?
In the cable world the term structured cabling gets thrown around often. People say it like a buzzword. What exactly is structured cabling? In many data centers the cabling methodology used is defined as “point to point”. This is running patch cables (or jumpers) directly to and from the hardware that needs connectivity. Structured cabling is the standardized architecture and components for communications cabling specified by the EIA/TIA TR42 committee and used as a voluntary standard by manufacturers to insure interoperability. In a structured cabling system, a series of patch panels and trunks are used to create a structure that allows for hardware ports to be connected to a patch panel at the top of the rack.

Structured Cabling

40G Structured Cabling Components
As a result of the emergence of high-data-rate systems such as 10, 40, and 100 Gigabit Ethernet, laser-optimized multimode fiber has become the dominant fiber choice. These 50-micron fibers (OM3 and OM4) are optimized for 850-nm VCSEL transceivers, which provides the optimum technical and economic solution for 40G operation and is the dominant structured cabling options used in today’s data centers. Among, SFP+ transceiver (usually uses a LC optical connector) is the dominant transceiver used for 10G applications. And the QSFP+ transceiver (usually uses a 12-fiber MTP connector) is the dominant transceiver used for 40G applications. Other essential components for 40G structured cabling include MTP trunk cables, MTP-LC harness/breakout cables, LC or MTP patch cables, MTP-LC cassette modules, MTP adapter panels and MTP rack mount holders.

Our Transceivers for 10G, 40G Short Reach Application:

Part Number Product Photo Description
SFP-10GSR-85 SFP-10GSR-85 Cisco SFP-10G-SR Compatible 10GBASE-SR SFP+ 850nm Transceiver
QSFP-40G85-1M QSFP-40G85-1M Cisco QSFP-40G-SR4 Compatible 40GBASE-SR4 QSFP+ 850nm Transceiver


40G Structured Cabling Solutions
When designing a networking system, it is important to plan the cabling system in advance. The goal is to address current network requirements as well as accommodate future growth. A 40G structured cabling system provides a flexible cabling plan to address the commonly performed tasks of moving, adding, or changing the infrastructure as the network grows. Here I may give several 40G structured cabling cases mainly based on Cisco switches.

Connectivity with SFP Port Replication (Cross-Connect) for 40G Connectivity
This case uses a cross-connect, also referred to as a patch-panel field. This port-level patching location allows connectivity between any port and any other port in an organized way. The flexibility created by this central patching field guarantees the ability to achieve any desired link configuration.

10G cross-connect for 40G

Physical Rack Layout of 10G Connectivity with SFP Port Replication for 40G Connectivity
In this case, we use MTP-terminated trunk cables. Permanent structured cabling links would be deployed using these MTP-based trunks to create connector patching fields at each end. Then short MTP or LC jumper patch cables would be used to make the connection from the patch field to the QSFP+ or SFP+ optics at the switch port.

Physical Rack Layout of 10G Connectivity  for 40G

10G Connectivity with Interconnect for 40G Connectivity
Some links may not require the flexibility of having a cross-connect, and in this case, a direct interconnect would be deployed. In this situation, the structured cabling (MTP trunk) would still be terminated in rack-mounted patching panels at the network devices. Then there is an interconnect using a jumper from the patch field directly to the device.

10G Connectivity with Interconnect for 40G

40G Connectivity with Interconnect for 40G Connectivity
In the future, when the core is upgraded to support QSFP+ optics and 40-Gbps flows, the existing structured cabling infrastructure can be maintained, and only the harness assembly that terminated in the LC-based Cisco Nexus 7000 Series I/O module need to be replaced. The rest of the infrastructure from the Cisco Nexus 6000 Series Switch through the patch-panel field would remain the same for 40G flows.

40G Connectivity with Interconnect

Corresponding Product Series

No. Part Number Product Photo Description
A FS12OM3-2MTPX-x 12-fiber MTP-to-LC OM3 harness cable  12-fiber MTP-to-LC OM3 harness cable
B FS12OM3-LGX-2MTP-XX 12-fiber OM3 LC duplex to MTP(pinned) cassette 12-fiber LC duplex to MTP cassette module
C OM3-LC-LC-DX-FS LC-LC duplex OM3 fiber patch cable LC-LC duplex OM3  fiber patch cable
D FS144OM3-2MTP-x 144-fiber OM3 MTP trunk cable 144-fiber OM3 MTP(male) trunk cable
E FAP-HV-4MTPUUD 48-fiber (4-port) MTP adapter panel 48-fiber (4-port) MTP adapter panel
F FS12OM3-2MTP-x MTP(pinned) to MTP(pinless) OM3 patch cable MTP(male) to MTP(female) OM3 patch cable; Type-B polarity
J FS8OM3-2MTPX-x 8-fiber MTP-to-LC OM3 harness pigtail 8-fiber MTP-to-LC OM3 harness pigtail
K FS-4RU-MX 4U 19 4U 19″ rack mount holder


Fiberstore supplies a wide range of fiber optic transceivers and MTP/MPO assemblies such as MPO/MTP® trunk cables, harness cables, cassette module and adapters are available. In order to better satisfy your unique demands, we also support custom or OEM service. For more information, please contact us over sales@fs.com.

Tags: , , , , , , ,
FS.COM FHD Fiber Enclosure
January 2017
« Dec