Base-12 MTP/MPO cabling is commonly used as the industry standard for high-density network building for decades. However, Base-8 has gradually entered the market to replace Base-12 to some extent since transceivers are guiding our industry from 10G to 40G, 100G and even 400G Ethernet. On Base-8 vs Base-12 comparison, Base-8 offers more efficient fiber optic links for transceivers such as QSFP+ and QSFP28, which only utilize eight fibers. This post will mainly introduce the applications based on Base-8 MTP/MPO cabling.
There are three main transmission links based on Base-8 MTP/MPO cabling, namely duplex fiber optic transmission links (10G-10G), parallel fiber optic transmission links (40G-40G, 100G-100G, etc.), parallel to duplex fiber optic transmission links (40G-10G, 100G-10G/25G). Here we will explain the applications from the three aspects respectively.
The duplex fiber optic transmission link normally uses duplex interconnect solutions. As shown in the following figure, the structured cabling solution allows for patching on both ends of the 10G duplex LC optical network. The solution deploys 8-fiber MTP/MPO-LC cassette module on one end of the link. A MTP/MPO adapter panel and an 8-fiber MTP/MPO-LC harness cable on the other end.
The MTP/MPO adapter panel and the 8-fiber MTP/MPO-LC harness cable could be replaced by an 8-fiber MTP/MPO-LC cassette module and duplex LC fiber cable as well. And the MTP/MPO trunk cable deployed in the middle is available with a multiple of 8-fiber connectors. That is to say, the total fiber count could be 8, 16, 32, etc. The use of MTP/MPO trunks provides a robust solution that allows the cable to be placed in cable trays without the fear of the trunk cable being crushed resulting in fiber damage. With this structured cabling, one can remove or add components in the whole link easily. Since two ends of the link use LC-LC duplex connection, this solution could be regarded as 2-fiber to 2-fiber solution in Base-8 MTP/MPO cabling.
The parallel fiber optic transmission links could be divided into two main solutions. The links on both ends could use 8-fiber to 8-fiber connection (40G-40G), 20-fiber or 24-fiber connection (100G-100G).
8-Fiber to 8-Fiber Connectivity
The easiest parallel fiber optic transmission link of Base-8 MTP/MPO cabling is to directly connect two QSFP+ transceivers like 40GBASE-SR4 with an 8-fiber MTP/MPO cable. This type of direct connectivity is only suggested for short distances within a given row of racks or cabinets.
Of course, you can upgrade this 8-fiber to 8-fiber solution with MTP/MPO trunk cables and MTP/MPO adapter panels deployed to replace the 8-fiber MTP/MPO cable. This offers a durable solution that allows the cable to be placed in cable trays without the fear of the trunk cable being crushed. With the trunk cables, more QSFP+ transceivers and 40G links could be supported.
20-Fiber or 24-Fiber Connectivity
The Base-8 MTP/MPO cabling can also be used to connect two transceivers which could support 20-fiber or 24-fiber connectivity such as the 100GBASE-SR10. The figure below shows an interconnect structured cabling based on Base-8 MTP/MPO cabling. This solution offers connectivity from one 100G CFP to another 100G CFP transceiver (or 20-fiber to 20-fiber connection). It uses 24-fiber MTP/MPO to three 8-fiber MTP/MPO breakout harnesses cable to transmit the signal across a Base-8 MTP/MPO cabling.
The parallel to duplex fiber optic transmission links could be divided into two main solutions as well. The links on both ends could use 8-fiber to 2-fiber connection (40G-10G, 100G-25G), 20-fiber to 2-fiber connection (100G-10G).
8-Fiber to 2-Fiber Connectivity
The most common 8-fiber to 2-fiber connection is 40G-10G and 100G-25G transmission. This is the direct connectivity solution of a Base-8 MTP/MPO cabling. For example, one can use an 8-fiber MTP/MPO-LC harness cable to connect a 40G QSFP+ transceiver and four 10G SFP+ transceivers, or to connect a 100G QSFP28 transceiver and four 25G SFP28 transceivers.
This type of direct connectivity is only suggested for short distances within a given row or in the same rack or cabinet as well. For longer distances, one can use MTP/MPO adapter panels and MTP/MPO-LC cassette on the two ends of the link with MTP/MPO trunk cables in the middle.
20-Fiber to 2-Fiber Connectivity
The parallel to duplex fiber optic transmission links can be realized by 20-fiber to 2-fiber connectivity as the following:
In this solution, the 24-fiber MTP/MPO breakout cable and MTP/MPO-LC cassette are used to connect the 100G CFP transceiver and ten 10G SFP+ transceivers. The 24 fibers are divided into three MTP/MPO-8 connectors, and thus transmit over ten duplex LC cables, realizing the 20-fiber to 2-fiber connectivity in the whole link.
From all the above, there are various Base-8 MTP/MPO cabling solutions available in duplex, parallel, and parallel to duplex fiber optic transmission links. Base-8 connectivity enables a lean and clean data center without the need for extensive data wiring. It increases network efficiency and reduces the cost of converting Base-12 system to Base-8 system by using multiple connected devices. And the Base-8 connectivity can be easily used for two-fiber transceiver systems (Base-2 systems). It offers more flexibility for network connection in 10G, 40G, 100G, etc., eliminating the need for further compatibility issues.