Tag Archives: CFP

Preparation for 40G/100G Migration

10G is now common in large enterprises. New network trends continue to drive the demand for high-speed Ethernet, such as the virtualization trend, network storage trend, I/O convergence trend, and data center network aggregation trend. So 40G and 100G as well as corresponding equipment are introduced into the market. The migration from 10G to 40G/100G is inevitable.

IEEE and TIA Standards

Before planning for migration to 40G/100G network, we should better know well about high-speed Ethernet. The following will talk about it from the side of standards. Because structured cabling systems design is always guided first by standards. The standards for 40G and 100G are significantly different from previous generations; active equipment and how information is transmitted are unique.

First, it’s IEEE standards. IEEE creates the standards that define performance parameters. IEEE 802.3ba 40Gb/s and 100Gb/s Ethernet is the only current standard that addresses the physical layer cabling and connector media maximums for 40/100G fiber channel requirements. IEEE 802.3ba-2010 standard was approved at the June 2010 IEEE Standards Board meeting. The standard is shown in the following table.

Fiber Type Max Distance Max Channel

Insertion Loss

Max Channel Connector

 Insertion Loss

10G OM3 300m 2.6 dB 1.5 dB
10G OM4 550m 2.6 dB 1.5 dB
40/100G OM3 100m 1.9 dB 1.5 dB
40/100G OM4 150m 1.5 dB 1.0 dB

Second, it’s TIA (Telecommunications Infrastructure Standard). For data centers, TIA defines how to apply the parameters to structured cabling systems. It establishes design criteria including space and layout, cabling infrastructure, tiered reliability, and environmental considerations. The standard recommends using the highest capacity media available to maximize infrastructure lifespan.

40G/100G Using MPO/MTP Interface

1G and 10G networks use GBIC (Gigabit interface converter). For example, generally the transceiver SFP+ (small form-factor pluggable) is for 10G network. Later the fiber connectivity in high-speed active equipment becomes condensed and simplified. Transceivers for 40G and 100G are QSFP (quad small form-factor pluggable), CFP and CXP (100G form-factor pluggable). MPO/MTP is the designated interface for multimode 40/100G, and it’s backward compatible with legacy 1G/10G applications as well. Its small, high-density form factor is ideal with higher-speed Ethernet equipment.


Figure1. MPO/MTP Connector

40G and 100G Ethernet employ parallel optics. Data is transmitted and received simultaneously on MTP interfaces through 10G simplex transmission over each individual strand of the array cable.

After introducing some basics of the high-speed Ethernet, we’ll discuss the structured cabling system of migration to 40G and 100G networks in the simplest and most-effective way.

12- or 24-Fiber Cabling Infrastructure

The system includes configurations for 10G to 40G/100G networks over 12- or 24-fiber MTP cabling. What’s the difference between the two methods? Which one is better? The sections will compare the two from the sides of migration, density and congestion.

Migration To achieve the migration, components like trunks, harnesses, array cords, modules, and adapter plates are needed. With the 40G 12-fiber legacy configurations, a second trunk and another set of array harnesses will be needed to achieve 100% fiber utilization (as shown in Figure 2). For 100G, it also needs these additional components with 12-fiber legacy configuration. But with 24-fiber trunks, a single cable can support a 1G-100G channel and simplify network upgrades immensely (as shown in Figure 3). When equipment is upgraded, there is no need to install new trunks. In addition, limiting changes can reduce the inherent risks to network security and integrity.


Figure2. 12-Fiber Cabling


Figure3. 24-Fiber Cabling

Density The higher density connectivity, the more rack space for active equipment. Thus less floor space is needed. In this way, 24-fiber cabling has the obvious advantage. If the active equipment is configured for 24-fiber channel/lane assignments, there will be twice as as many connections with the same number of ports compared to 12-fiber.

Congestion The more connectivity you are able to run in the same footprint, the more crowded it can become at the rack or cabinet. Fewer trunks reduce cable congestion throughout the data centers. Using 24-fiber MTP trunks for the cable runs will save half the number of cables versus 12-fiber in the network. Runs carry a lighter load, fibers are easier to manage, and improved airflow reduces cooling costs. So 24-fiber MTP trunks offer a huge benefit.


The high-speed network will become more and more popular. It’s very important to know something about the migration to 40G/100G. To upgrade your network, 24-fiber MTP will be a better fiber cabling choice compared with 12-fiber. Do you prepare well for the great migration?

Which One Will You Choose for Your 40/100G Network, OM3 or OM4?

40G has been widely used in data centers. 100G will also come soon. To meet these high bandwidths, related fiber cables are needed. OM3 and OM4 can be used to transmit parallel optical signal. But what is their difference? Which one will you choose for your network?

Both OM3 and OM4 are laser optimized fiber. Their cores size is 50/125. Connectors are the same and both operate 850nm VCSELS (Vertical-Cavity Surface-Emitting Lasers) transceivers. So the difference lies in the construction of the fiber cable, which means OM4 cable has better attenuation and can operate at higher bandwidth than OM3.


Attenuation is the reduction in power of the light signal as it is transmitted (dB). Attenuation is caused by losses in light through the passive components, such as cables, cable splices, and connectors. As the connectors are the same, so the difference in OM3 and OM4 performance is in the loss (dB) in the cable. The maximum attenuation of OM3 allowed at 850 nm by the standards is less than 3.5 dB/km, and less than3.0 dB/km for OM4.

Another factor influencing the cable function is dispersion. Dispersion is the spreading of the signal in time due to the different paths the light can take down the fiber. It has two types: chromatic and modal. In multimode fiber transmission, chromatic dispersion is negligible and the modal dispersion is the limiting factor.

The modal dispersion determines the modal bandwidth that the fiber can operate at and this is the difference between OM3 and OM4. Modal bandwidth represents the capacity of a fiber to transmit a certain amount of information over a certain distance and is expressed in MHz*km. The higher the modal bandwidth the more information can be transmitted. The modal bandwidth of OM3 is 2700 megahertz*km while the mod0al bandwidth of OM4 is 4700 megahertz*km. Thus, OM4 allows the cable links to be longer.

Compared with OM3, OM4 has a lower attenuation and operates at a higher modal bandwidth. That means over OM4 less power is lost during the signal transmission and the signal can be transmitted further or through more connectors (which add to the losses). The following table shows the Ethernet distances at 850 nm supported by OM3 and OM4 respectively.

1Gb 10Gb 40Gb 100Gb
OM3 1000m 300m 100m 100m
OM4 1000m 500m 150m 150m

So why is the standard for 40G only 100m on OM3 and 150m on OM4 compared to 300m and 500m for 10G? There are two reasons. First, when the IEEE 802 standard was created they decided to create a standard based on “relaxed” transceiver specifications so that smaller and lower cost transceivers could be used. Two functions of 10G transceivers (clock recovery and attendant re-timing) are absent in both QSFP+ (40G) and CFP (100G) devices. Second, the standard allows for transceivers with wider spectral width lasers which increase chromatic dispersion (pulse spreading). The quality of transceivers is also a factor.

Which will you choose for your 40/100G network, OM3 or OM4? Except the transmission distance and the cable costs, there are additional factors to consider such as the number of cross connects required and the mix of 40G port to 40G port and 40G port to 10G port. Because 40G signal is transmitted across eight pairs of fiber each with 10G. Similarly, it is important to take into account the likely location of future 100G equipment and the possible 100G to 100G, 100G to 40G and 100G to 10G connectivity requirement.

A Complete Guide of Installing or Removing Transceiver Modules (Part I)

After learning more about a variety basic or conclusive knowledge of transceiver modules these days, I believe you must have a new understanding or a deeper perception on the transceiver modules. In fact, that’s just a tip of iceberg. My blog will continue to bring more information about the transceiver modules, also the other knowledge of fiber optic communication, network, telecom etc. to all of my friends who like this field and like my blog. Since we discuss so much about the theories of the transceiver modules, today, I prefer to talk about something practicle, for instance, some knowledge about installing or removing different kinds of transceiver modules.

As we know, the commonly used transceivers include the following 8 types:

The following content will cover the knowledge of installing or removing for these types of transceiver modules, namely today’s main topic. But first of all, I want to talk about some preparations and considerations before starting the main topic.

What equipment should we need to install a transceiver module?
When installing a transceiver module, some tools you should need in order to make your installation go well. The following is a list of such tools which are recommended:

  • A Wrist strap or similar personal grounding device designed to stop ESD occurrences.
  • An Antistatic mat or similar which the transceiver can be placed on.
  • Fibre-optic end-face cleaning tools and inspection equipment.
  • A flat head screw driver is require to install a XENPAK transceiver module.

What should we need to know before or during installing or removing a transceiver module?
In order to ensure the safety and avoid leading the unnecessary losses, there are some items which we should consider before and during installing and removing the transceiver modules.

  • To preventing the cables, connectors, and the optical interfaces from damage. We must disconnect all cables before removing or installing a transceiver module.
  • Please be aware that the regular removal and installation a transceiver module can shorten its useful life. Thus, transceivers should not be removed or inserted more often than is required.
  • Transceiver modules are sensitive to static, so always ensure that you use an ESD wrist strap or comparable grounding device during both installation and removal.
  • Do not remove the dust plug from the transceiver slot if you are not installing the transceiver at this time. Similarly, we must use the dust plug to protect the optical bore if we don’t use the transceivers.

How to Install or Remove Transceiver Modules
1. How to Install or Remove GBIC Transceiver Module
GBIC Installing Steps
step 1: Firstly you should attach your ESD preventive wrist strap to your wrist to prevent ESD occurrences.
step 2: Remove the GBIC transceiver from its protective packaging.
step 3: Verify that the GBIC transceiver module is the correct model for the intended network.
step 4: Using your thumb and forefinger, grip the sides of the GBIC transceiver and carefully align it with the GBIC socket opening on the device.
step 5: You can now carefully insert the GBIC transceiver module through the socket flap and slide it into the GBIC socket. A click will be heard once the GBIC is locked into the socket. Please ensure that the GBIC is inserted carefully straight into the socket.
(Please note: you should keep the protective dust plugs in place until making a connection. You should also inspect and clean the SC connector end faces immediately prior to making a connection.)
step 6: The dust plugs from the network interface cable SC connectors can now be removed, ensuring that these are saved for later use.
step 7: Next, inspect and clean the SC connector’s fiber optic end faces.
step 8: Remove the dust plugs from the optical bores on the GBIC transceiver module.
step 9: You can now attach the network interface cable SC connector to the GBIC.

GBIC Removing Steps
Please be aware that GBIC transceiver modules are static sensitive so you should always use an ESD wrist strap or similar grounding device when coming into contact with the device. Transceiver modules can also reach high temperatures so may be too hot to be removed with bare hands.
step 1: Disconnect the cable from the GBIC connector.
step 2: Release the GBIC from the slot by pressing the two plastic tabs located on either side of the GBIC (They must be pressed at the same time).
step 3: Once released carefully slide the GBIC straight out of its module slot.
step 4: The GBIC transceiver module should now be placed safely into an antistatic bag.

2. How to Install or Remove SFP Transceiver Module
SFP/SFP+ Installing Steps
SFP modules can have 3 different types of latching devices which secure the SFP into the module socket, so please determine which latching device your module has before installation or removal of the device.
step 1: Firstly you should attach your ESD preventive wrist strap to your wrist as well as to the ESD ground connector. A metal surface on your chassis is also acceptable.
step 2: Next, remove the SFP transceiver module from its packaging.
(Please note: You shouldn’t remove the optical bore dust plugs yet.)
step 3: Check the SFP transceiver to ensure that it is the correct model for the network
step 4: Locate the send (TX) and receive (RX) markings. These will allow you to identify the top of the SFP transceiver module.
(Please note: Certain SFP transceiver modules may represent the TX and RX marking with arrowheads. The direction of these will allow you to determine the send and receive.)
Pointing from the SFP transceiver module connector = Transmit/TX
Pointing toward the connector = Receive/RX
step 5: Align the SFP transceiver module with the module port.
(Please Note: Devices can have different SFP module socket configurations. It is possible to have either a latch-up or a latch-down orientation. Firstly make sure that you are installing an SFP transceiver module with the correct latch orientation for your device.)
step 6: Insert the SFP Transceiver Module into the socket until you feel the SFP’s connector latch into place. Ensure that you press the SFP firmly into the slot using your thumb.
(Please note: For those SFP transceiver modules which have an actuator latch, you must press on both the transceiver faceplate and the actuator button to ensure that the transceiver is correctly connected.)
step 7: Verify the SFP transceiver module installation. Attempt to remove the SFP without releasing the latch, if it cannot be removed then it is correctly seated. If it can be removed reinsert the SFP and press harder with your thumb, until you can verify that it is correctly seated.
step 8: You can now remove the dust plugs from the network interface cable LC connectors. You should save the dust plugs for future use.
step 9: Inspect and clean the fibre-optic end-faces on the LC connector.
step 10: You can now remove the dust plugs from the SFP transceiver module’s optical bores. As soon as this has been completed you must attach the network interface cable LC connector to the SFP.
(Please note: If you are connecting a 1000BASE-T SFP transceiver module to a copper network you should firstly insert the Category 5 network cable RJ-45 connector into the SFP transceiver module RJ-45 connector. Then Insert the other end of the network cable into an RJ-45 connector on a 1000BASE-T-compatible target device.)
step 11: Check the port status LED, if it turns green the SFP transceiver module has established a link with the target device. If the LED is off please ensure that the target device is powered on before troubleshooting. The LED will turn amber for approximately 30 seconds prior to turning green.
step 12: Reconfigure and reboot the target device if required.

SFP/SFP+ Removing Steps
Please be aware that SFP transceiver modules are static sensitive so you should always use an ESD wrist strap or similar grounding device when coming into contact with the device. Transceiver modules can also reach high temperatures so may be too hot to be removed with bare hands.
step 1: Attach your ESD wrist strap and the ESD ground connector to a metal surface on the device chassis.
step 2: Next disconnect the network cable from the SFP transceiver module connector. You should then reinstall the dust plugs on the optical bores and fibre optic cable LC connectors.
step 3: Release and remove the SFP transceiver module from the socket connector.
Mylar Tab Latch: for SFPs with a Mylar Tab Latch, you should first pull the tab in a downward direction until the SFP is released from the socket connector. Then the SFP module can be pulled directly out, ensuring not to twist or pull the Mylar tab.

Actuator Button Latch: for SFPs with an Actuator Button Latch, you should gently press the button on the front of the transceiver until it clicks. This should release the SFP transceiver module from the socket connector, following which the SFP transceiver module can be carefully removed from the module slot. This should be done straight, ensuring not to twist or bend the module.

Bail Clasp Latch: For SFPs with a Bail Clasp Latch, the latch should be pulled out and down to eject the SFP transceiver module from its socket.
step 4: The removed SFP transceiver module should now be placed safely in a protective environment such as an antistatic bag.

Warm Tips
About how to install or remove XENPAK, X2, XFP, QSFP/QSFP+ and CFP will be continued next week. Please focus on my blog update on next Monday.

Article Source: http://www.fiber-optic-transceiver-module.com/a-complete-guide-of-installing-or-removing-transceiver-modules-part-i.html