MTP®/MPO 8 and MTP®/MPO 12 Cabling System, Which to Choose?
As we all know, traditional Base-2 connection (LC cabling) can not meet the high speed and high-density demand of the data center deployed with 40G or 100G. Under such circumstances, two new connection methods — Base-12 and the later Base-8 MTP®/MPO connections have been adopted in many cases. Then, What are MTP® 12 and MTP® 8 cabling? Which should we choose in our MTP® cabling system? Get details from the following text.
Note: MTP® is a registered trademark of US Conec Ltd. . This is the term US Conec uses to describe their connectors. American Conec MTP® products are fully compliant with MPO standards. Therefore, the MTP® connector is a type of MPO connector.
What Is MTP®/MPO 8 Cabling?
An MTP®/MPO-8 cabling is based on the backbone's Type B male/pinned MTP® trunk. It makes use of MTP® fiber optical links based on increments of 8 fibers and 8-fiber MTP® fiber optic connectors. For example, 8-fiber, 16-fiber and 24-fiber trunk cables all belong to Base-8 MTP® cabling system. In MTP®/MPO 8 cabling, 12-fiber trunk cables don't exist. MTP®/MPO 12 cabling is as follows:
MTP®/MPO 8 connectivity can be easily used for Base-2 cabling systems since the number eight is wholly divisible by the number two. For example, an 8-fiber MTP® cable could be easily converted to 4 duplex LC cables. Of course, you can use other solutions like MTP®-LC modules to realize the smooth conversion from Base-8 to Base-2 connectivity.
What Is MTP®/MPO12 Cabling?
An MTP®/MPO 12 cabling is based on the backbone's Type A female/unpinned MTP® trunk. It makes use of MTP® fiber optical links based on increments of 12 fibers and 12-fiber MTP® fiber optic connectors. Base-12 appears ahead of Base-8. Therefore, it still remains the mainstream in MTP® cabling systems. MTP®/MPO 12 cabling is as follows:
Likewise, MTP®/MPO 12 connectivity can be easily used for Base-2 cabling systems since the number twelve is wholly divisible by the number two as well. Here is a picture showing the conversion from Base-12 to Base-2 system using MTP®-LC breakout modules.
Base-8 vs Base-12 MTP® Cabling, Which Should We Choose?
MTP®/MPO 12 connectivity has served the data center industry for nearly 20 years. The deployment of 12-fiber MTP® connectors has grown exponentially throughout the process. However, as the transceivers used by switch, server, and storage manufacturers in their equipment have changed gradually from 10G Ethernet to 40G and 100G, and even up to 400G, the need for MTP®/MPO 8 connectivity is becoming increasingly apparent. The following table illustrates the differences in cabling for different rates:
|Duplex OM3/4||100-150 m||BiDi WDM (UNIV)||BiDi WDM||To Be Determined|
|Parallel OM3/4||100-150 m||SR4/eSR4 4x10G||Gen1: SR10 10x10G; Gen2: SR4 4x25G||
Gen1: SR16 16x25G; Gen2: SR8 8x50G; Gen3: SR4 4x100G
|Duplex Single-mode||2-10 km||LR4 (10 km); LRL4 (2 km)||LR4 (10 km); CWDM4 (2 km)||WDM(10 km); WDM (2 km)|
|Parallel Single-mode||300-1,000 m||PLR4||PSM4||PSM4 4x100G (100G via WDM, symbol rate, encoding)|
From the above, we can consider the following two main aspects to decide whether to choose Fiber-12 or Fiber-8:
For Fiber Utilization
In high-density network cabling, MTP®/MPO 12 has an advantage due to its higher core count and density. Although the Base-12 MPO cabling is the most common choice for most data center operators, there are still no standardized transceivers using 12 fibers. With Base-8 MTP® links, customers can directly connect fibers to these transceivers without any fiber waste. If a 12-fiber connector is used with a transceiver that only requires eight fibers, then four fibers will be left unused. To utilize all fibers, a conversion cable can be used to convert the Base-12 cabling to Base-8 cabling (e.g., two Base-12 to three Base-8). However, this can cause additional insertion loss and reduce cable performance.
In addition, when using MTP® to LC duplex breakout harnesses to connect switch line cards, Base-8 harnesses easily route to all common port count line cards, as all common line cards contain a number of ports wholly divisible by four (since a Base 8 fiber provides four LC duplex connections). If Base-12 MTP® to LC duplex breakout harnesses are used, only 6 LC duplex connections will be available. But these harness cables can't fully connect to line cards with 16 or 32 ports since 16 and 32 are not wholly divisible by 6. Therefore, for better fiber utilization, MTP®/MPO 8 cabling is a better choice. Of course, if you don't mind the fiber wasting, MTP®/MPO 12 cabling could also be selected.
For Future Cabling System
In smaller networks with 10G connections, both Base-12 and Base-8 MTP® cabling can be seamlessly converted to Base-2 cabling, making either of them feasible. However, for larger networks with 40G, 100G, or even 400G connections, a Base-8 solution is more widely accepted since a greater number of 40G and 100G circuits use eight-fiber transceivers. This is also true for 400G direct connections that use 400G QSFP-DD transceivers and MTP®-16 trunk cables. Additionally, 8-fiber cabling can work seamlessly with 24-fiber cabling, as a single 24-fiber can break out into three 8-fibers. Customers deploying 10G data rates today can still use the Base-8 system, as upgrades to 40G or 100G will be simpler and more cost-effective in the future. However, Base-12 connectivity is not optimal for 8-fiber transceiver systems.
FAQs on MTP®/MPO 8 vs MTP®/MPO 12 Cabling System
Q: Can We Use MTP®/MPO 8 and MTP®/MPO 12 Together Directly?
A: It is never possible to directly mix the components of Base-8 and Base-12 connectivity, or plug a Base-8 trunk into a 12-fiber module. Because a Base-12 trunk cable normally has unpinned MTP® connector on both ends, and requires the use of pinned 12-fiber breakout modules, while a Base-8 trunk cable is manufactured with pinned MTP® connectors at both ends.
Q: Is It Possible to Use MTP®/MPO 8 and MTP®/MPO 12 Cabling in the Same Data Center?
A: It is possible to deploy both Base-8 and Base-12 connectivity within the same data center, just as long as the links are separate.