MTP Connectivity — Low-loss Multifiber Connectivity

It is not difficult to understand that MTP connectivity is widely applied in 40G and 100G network applications because it is a multifiber connectivity, which can meet the demand for high-density cabling. As a matter of fact, there is another key advantage of MTP connectivity, that is low-loss. With the length and type of the fiber cable, number of connectors and splices all contributing to the link loss, there is no doubt that insertion loss is inevitable during the cabling process. Therefore, cabling solution with low-loss will be preferred by data center managers, who are now regarding optical insertion loss budgets as one of the top concerns. But what contributes to low-loss in MTP connectivity? This post will show you the answer.

Low-loss Connector

Typical MPO/MTP fiber connector, which is used for 40 and 100 GbE deployments, has insertion loss values that range from 0.3 dB to 0.5 dB. In addition, MPO/MTP connector is structured with MT ferrule which has low insertion loss and can provide accurate fiber alignment. Take 12 fiber MPO connector and 24 fiber MPO connector for example, with low-loss ferrules, the insertion loss of both two type of connectors can be rated at 0.35 dB maximum. Reading this, you may ask shouldn’t the result be that higher fiber count will lead to higher insertion loss? The answer is no. Because when using proper polishing techniques, 24-fiber MPO/MTP terminations can meet the same performance levels as 12-fiber MPO/MTP assemblies.

Low-loss Cable

We know that OM3 and OM4 fibers used in MTP connectivity utilize 850 nm source, and IEEE 40GBASE-SR4 and 100GBASE-SR10 standards for 40 and 100 GbE over multimode fiber have more stringent loss requirements for these two types of fibers, which lowers the overall channel loss. As shown in the following table, as speeds have increased from 1 Gb/s to 40 and 100 Gb/s, maximum channel distance and loss has decreased significantly. For OM3 fiber cabling, the 40 and 100 GbE standards allows for a channel distance of 100 meters with a maximum channel loss of 1.9 dB, including a maximum connector loss of 1.5 dB; for OM4 fiber cabling, the distance is increased to 150 meters but with a maximum channel loss of 1.5 dB, including a maximum connector loss of 1.0 dB.

channel loss of OM3 and OM4 fibers

Note: Current TIA and ISO standards require a minimum of OM3 fiber, while TIA recommends the use of OM4 due to its longer transmission capabilities. In fact, the 100GBASE-SR4 standard that uses eight fibers (four for transmitting and four for receiving) at 25 Gb/s is anticipated to be supported by OM4 fiber to 100 meters, but to only 70 meters using OM3.

Conclusion

In today’s large virtualized server environments with high speed 40 and 100 gigabit Ethernet (GbE) backbone switch-to-switch deployments for networking and storage area networks (SANs), staying within the loss budget is essential for ensuring that optical data signals can be properly transmitted from one switch to another without high bit error rates and performance degradation. MTP connectivity, based on low-loss MPO/MTP connector, OM3 and OM4 fibers, is able to reduce the insertion loss to a minimum, which makes this low-loss multifiber connectivity take its place on the market.

Originally published at http://www.china-cable-suppliers.com/mtp-connectivity-low-loss-multifiber-connectivity.html

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How Much Do You Know About MTP-8 Solution?

It is not difficult to find that MTP components are widely used for high density application in data centers. As 40G and 100G network has been utilized by many data centers, two common types of cabling solutions are popular among data center managers—MTP-12 solution and MTP-24 solution, which use links based on increments of 12 and 24, such as 12-fiber MTP MTP trunk cable and 24-fiber MTP MTP trunk cable. In addition to MTP-12 solution and MTP-24 solution, there is another MTP solution—MTP-8. So how much do you know about MTP-8 solution? This article will guide you to learn about MTP-8 solution.

Overview of MTP-12 Solution and MTP-24 Solution

Before we come to MTP-8 solution, let’s have a brief overview of MTP-12 solution and MTP-24 solution. In 40G networking applications, a 12-fiber MTP fiber connector is used: 10G is sent along each channel or fiber strand in a transmit and receive direction, and 8 of the 12 fibers are used to provide 40G parallel transmission. In 100G network applications, a 24-fiber MTP fiber connector is used: 10G is sent along each channel or fiber strand in a transmit and receive direction, and 20 of the 24 fibers are used to provide 100G parallel transmission. Here are two figures for you to have a better understanding of this.

MTP-12 Solution

MTP-12 Solution

MTP-24 Solution

MTP-24 Solution

Overview of MTP-8 Solution

In a MTP-8 solution or Base-8 solution, 8-fiber MTP MTP trunk cable, 24-fiber or 32-fiber MTP MTP trunk cable can be used to transmit data. In brief, MTP-8 solution uses cable links based on increments of the number “eight”. Since MTP-12 solution and MTP-24 solution have been using in the data center for years, you may ask is t necessary to use MTP-8 solution? From the figure below, we can find that in fiber optic industry, optical transceiver roadmap changes rapidly from 10G to 40G, 100G and even up to 400G. With faster speeds spreading out into data center racks and SANs, there is a need for a more manageable grouping. For 40G network applications and above, optical signals are usually carried over eight fibers, and terminated at the switch in a MTP-8 QSFP transceiver which combines eight fibers.

40G 100G 400G use MTP-8 solution

From the figure, we can also learn that for Ethernet transmission ranging from 40G to 400G, all roads lead to 2-fiber and 8-fiber solution. For 40G/100G and future 400G applications, the use of 12-fiber MTP solution would result in 33% of the optical fibers unused. Thus it is expected that for 400G application, MTP-8 will gain widespread market acceptance.

Advantages of MTP-8 Solution

There are two primary advantages of MTP-8 solution—flexibility and 100% fiber utilization. Being wholly divisible by number “2”, MTP-8 solution can be easily used for two-fiber transceiver systems, just as MTP-12 solution can be. And for those who have deployed 12-fiber or 24-fiber MTP MTP trunk cable, how to ensure the 100% fiber utilization? MTP-8 solution can. You can use conversion cords or modules to transition two 12-fiber or one 24-fiber  trunk from backbone cabling into three 8-fiber MTP for 40G/100G equipment connection. But in this process, conversion modules will introduce additional insertion loss into the channel and conversion cords. Thus deploying MTP-8 solution directly can ensure 100% fiber utilization without the additional cost and insertion loss of MTP-12 to MTP-8 conversion devices. In a word, for the most common 40G/100G/400G transceiver types, MTP-8 solution offers the most flexibility and uses the fibers to the fullest.

Conclusion

MTP-8 solution is considered as the most cost-effective connectivity solution for supporting the current and future 8-fiber applications. Anyone with a near-tern migration plan to adopt 40G or 100G in the data center will benefit a lot from adopting MTP-8 solution.