No Conversion vs. Conversion Module vs. Conversion Harness: Which to Use for 40G Parallel Solution?

When talking about 40G cabling, MPO cable is the most common choice for data center managers to use. Today, I’d like to talk about three types of MTP cabling options for 40G parallel connectivity. The first type is to deploy MPO 12 cable and ignore the unused four fibers. And the other two types are using conversion module or conversion harness to convert two 12-fiber links into three 8-fiber links. So the three cabling options—no conversion vs. conversion module vs. conversion harness: which to use for 40G parallel solution?

Solution 1: No Conversion

 

For no conversion scenario, 12-fiber based MTP trunk cables are deployed in the whole 40G connectivity. But in this situation, 33% fiber is not used. And there will be additional cost associated with the purchase of additional fiber. Moreover, the whole system includes unused fibers.

 

Figure 1: no conversion used, the whole link uses base-12 MTP/MPO cable

Solution 2: Conversion Module

 

With using conversion module, it can convert the unused fibers into usable fiber links. For every two 12-fiber MTP connectors in the backbone cable, you can create three 8-fiber links. Although there will be additional cost for the additional MTP connectivity, it can be offset by the cost savings from 100% fiber utilization in the structured cabling. When reusing existing deployed MTP cabling, great value will be gained if using conversion module to use all previously deployed fiber, and you eliminate the cost of having to deploy additional cabling.

 

Figure 2: use conversion module to convert two 12-fiber links into three 8-fiber links

Solution 3: Conversion Harness

 

This scenario uses standard MTP patch panels and 2x3 MTP conversion harness. It does not add any connectivity to the link and full fiber utilization is achieved. Although it seems attractive, it involves considerable cabling challenges. For instance, if you only need two 40G connections to the equipment, what do you do with the third 8-fiber MTP connection? Or what if the 40G ports are in different chassis blades or completely different chassis switches? The result will be long assemblies, which will be difficult to manage in an organized way. For this reason, this kind of solution is expected to be the least desirable and so the least deployed method.

 

Figure 3: use conversion harness to convert two 12-fiber links into three 8-fiber links

No Conversion vs. Conversion Module vs. Conversion Harness

 

For the three types of connectivity solutions, the “No Conversion” solution, using traditional 12-fiber MTP connectivity and ignoring unused fibers, has the advantage of simplicity and lowest link attenuation. And as it does not use 33% of the installed fiber, it then requires more cable raceway congestion.

The “Conversion Module” solution, converting two 12-fiber links into three 8-fiber links through a conversion patch panel, uses all backbone fibers and creates a clean, manageable patch panel with off-the-shelf components. But it would lead to additional connectivity costs and attenuation associated with the conversion device.

The “Conversion Harness” solution, converting two 12-fiber links into three 8-fiber links through a conversion harness and standard MTP patch panel, uses all backbone fibers with additional connectivity. But it would create cabling challenges with dangling connectors and non-optimized-length patch cords that require customization.

Generally, the implementation of the conversion module solution is recommended, especially if you are using previously installed MTP trunks. Conversion module solution allows 100% fiber utilization while maintaining any port to any port patching. And if you are installing new cabling, then you can consider the no conversion solution, assuming that the cable raceway is not a concern. The conversion harness solution is typically deployed only in specific applications, such as at the ToR switch, where 40G ports are in a close cluster and patching between blades in a chassis switch is not required.

Conclusion

 

From what have described above, have you had a better understanding of these three types of 40G cabling solution? Each type has their own advantages and disadvantages. For those three solution choices—no conversion vs. conversion module vs. conversion harness: which is your choice for 40G parallel solution?

Originally published: www.fiberopticshare.com/no-conversion-vs-conversion-module-vs-conversion-harness.html

MTP Base-8 and Base-12: Correct Using Principles

In my previous post “MTP Links: Base-8 vs. Base-12 vs. Base-24”, I have done a comparison among Base-8 MTP, Base-12 MTP and Base-24 MTP. And from the post, we can conclude that Base-8 MTP link is the most future-proof option for the quickly-changing network requirements. But someone may ask “I have deployed Base-12 or Base-24 MTP link. Can I still deploy Base-8 MTP connectivity in the network? Or will Base-8 connectivity fit all applications?”. This post will answer these questions. Keep reading, you’ll get more.

Can Base-8 and Base-12 Be Used Together: Yes Or No?

 

The answer of this question depends. If directly mix the components and plug a Base-8 MTP cable into a 12-fiber module, then the answer is “No”. Base-8 components and Base-12 components are not designed to be plugged directly into each other. Generally, Base-12 MTP trunk cables have unpinned (female) MTP connectors on both ends, and require the use of pinned (male) breakout modules. But the Base-8 MTP trunk cables are manufactured with pinned connectors on both ends. So plugging a Base-8 trunk cable into a Base-12 breakout module will definitely not work. However, Base-8 and Base-12 MTP connectivity can be used in the same data center, but they should be maintained independently. As they are not interchangeable, some care is needed when managing the data center physical layer infrastructure, to ensure Base-8 and Base-12 components are not mixed within the same link.

 

Will One Type Fit All?

 

As known to all, 12-fiber MPO connectors are common in data centers, but they pose a problem when installed in a parallel path system—four unused fibers remain per connection. Typically, Base-8 can be a more cost-effective option for end-to-end MPO to MPO channels and architectures. Deploying Base-8 connectivity in duplex architectures for 10GBASE-SR and 25GBASE-SR will save 4% to 5% for data center managers, but if you’re running groups of 6-ports, Base-8 may result in a significant cost increase. Generally speaking, not one size fits all. Base-8 connectivity isn’t a universal solution. In fact, in some cases, Base-12 may still be more cost-effective. So it’s best to have both Base-8 and Base-12 connectivity in the same data center through careful management and labeling practices.

Summary

 

From what have described above, we can get these points. Although Base-8 and Base-12 MTP connectivity are not interchangeable, but they can be used in the same data center as long as the links are maintained separately. Base-8 and Base-12 MTP fiber links cannot be mixed and matched. Moreover, there is no one connectivity method fitting for all network applications. Base-8 connectivity method and Base-12 connectivity method can be used in different applications that can make the most of each type. For the most commonly 10G to 40G migration, Base-8 connectivity would be a strong consideration over Base-12.

Originally published: www.fiberopticshare.com/mtp-base-8-base-12-correct-using-principles.html

 

Other post you may be interested: MTP-8 Solution: Future-Proof Connectivity in Data Center

MTP Link Performance: Higher Fiber Count vs. Lower Fiber Count

With the pre-terminated plug & play benefits and ease of scalability from 10-40-100G, MPO/MTP connectors are rapidly becoming the norm of switch-switch connections. In the previous post “Introduction to MPO Connector”, I have talked about two types of MPO connectors—12 fiber MPO connector and 24 fiber MPO connector. And both the two MPO/MTP cable types can be used for 100G data transmission. So someone may ask “for MTP link performance, is there any difference between higher fiber count and lower fiber count, or, which produces better performance, higher fiber count or lower fiber count?”. This post simply tells the answer.

 

MTP Link: Higher Fiber Count ≠ Higher Insertion Loss

 

Generally, lower overall optical loss allows more margin for the network to operate, or in the case for some users, offers the option of more connections for patching locations. Then some network designers claim that higher fiber count will lead to higher insertion loss. Actually, this point of view is wrong. For both 12-fiber and 24-fiber MPO connector performance, the industry standard product rating is 0.5 dB maximum. When using proper polishing techniques, 24-fiber MPO/MTP terminations can meet the same performance levels as 12-fiber MTP assemblies. Furthermore, using low-loss ferrules, both 12 fiber and 24 fiber MPO connectors can be rated at 0.35 dB maximum.

 

MTP Link: Higher Fiber Count = Higher Performance

 

As you know, both MPO 24 fiber cable and MPO 12 cable can be used in 100G applications. MPO 12 cable can be used in 4x25G solutions, remaining 4 fibers unused. By using MPO 24 fiber cable, it can be converted into three 8-fiber 100G channels that run over one cable, with all 24 fibers used to support traffic. Let’s show an example to further prove which is better. If you need to support twelve 100G channels with the 4x25G standard, using 12 fiber MPO cable, you need to install 12 connectors, or 144 fibers total, with 33% of the fiber wasted. Using MPO 24 fiber cable supporting the same 12 channels, only 4 cables would be required, using 96 fibers total, at 100% fiber utilization.

Summary

 

From what have described above, we can summarize that MPO 24 fiber cable does not translate into higher insertion loss and can work as well as MPO 12 cable. Moreover, the 24 fiber MPO cable, while allowing the use of the ratified 100GBASE-SR10 20-fiber technology, can at the same time maximize the installed infrastructure investment in the event of 4x25G ratification and ultimate implementation. Choosing MPO 12 cable simply cannot accomplish this because it drives down return on investment and subsequently increases the total cost of ownership. And this is the exact opposite of the design intent of a data center infrastructure system.

Originally published: www.fiberopticshare.com/mtp-link-performance-higher-fiber-count-vs-lower-fiber-count.html

MTP Links: Base-8 vs. Base-12 vs. Base-24

For data center managers, deploying a fiber system that can easily be upgraded to future high-density network demands is the first thing that should be considered, because network reconfiguration would result in lots of time and money. So it is essential to deploy a fiber network which is easier to upgrade to the higher data rates from the start. For high density MTP links, Base-8 vs. Base-12 vs. Base-24: which one can provide a easier migration path for future network data rates?

Base-8 MTP Link

 

Base-8 MTP link is based on Type B male/pinned MTP trunk in the backbone. Base-8 MTP is SR4 ready, meaning that the backbone connectivity has the same fiber count as the SR4 transceiver. Base-8 MTP links allow customers to patch directly to SR4 transceivers without having to convert connectors with different fiber counts or waste excess fibers in the backbone. As SR4 transceivers are the preferred choices for 40G, 100G data rates and beyond, the Base-8 system is arguably the most scalable and future-proof backbone choice currently available. Customers deploying 10G data rates today can still deploy the Base-8 system knowing that upgrades to 40G or 100G will be much simpler and cost effective in the future. The following picture is 1x3 MTP conversion harness cables used in 40G/100G network with 100% fiber utilization.

 

Base-12 MTP Link

 

Base-12 MTP link is based on Type A female/unpinned MTP trunk in the backbone. Base-12 MTP is partially SR4 ready, because although SR4 is an 8 fiber interface, the Base-12 MTP connector is still compatible with it. Unlike the Base-8 MTP system, Base-12 does not utilize all of the fibers in the backbone when patched directly with SR4 transceivers, however multiple Base-12 MTP connectors can be combined and then converted so that full fiber utilization can still be achieved. Take our 2x3 MTP conversion harness cables for example, these MTP conversion cables have two 12-fiber MTP connectors on one end and three 8-fiber MTP connectors on the other end, which utilize all 12 fibers in two trunks for use with three port channels.

 

Base-24 MTP Link

 

Base-24 MTP link is generally deployed for 100G parallel links running over SR10 transceivers. Normally these links are between two high data-rate switches as opposed to switch to server. Base-24 can also be used for lower data rate backbone links such as 10G and 40G but this is normally only in cases where space and install time are the key drivers.

MTP Links: Base-8 vs. Base-12 vs. Base-24

• Initial Investment

Base-8 does require a higher up-front investment than Base-12 or Base-24 backbones due to the higher number of MTP connectors that are installed from day 1. However, research shows that the rapid increase in data rates will bring a return on investment within a few years. Furthermore, Base-8 provides the most efficient link constructions for SR4 meaning that the investment to convert Base-12 or Base-24 to SR4 will be largely if not completely avoided later.

• Fiber Utilization

Although Base-12 backbones are still the most common choice for most data center operators today, it should be noted that there are still no standardized transceivers using all 12 fibers in a Base-12 connector. Furthermore, the most likely transceiver interface SR4 in the future uses only 8 fibers. With this in mind, customers need to make the important decision whether to deploy Base-12 today and risk wasting 33% of backbone fibers tomorrow, or go straight for Base-8 knowing that it will be the best investment for the future.

• No. of Cables

Compared to Base-8 or Base-12, Base-24 reduces the number of cables required in the link, and sometimes this can be a compelling driver towards using this particular interface in the backbone. However, it should be noted that deploying Base-24 as a backbone choice will require MTP transition modules or MTP conversion harness to make it suitable for 10G and 40G data rates.

Summary

 

From what have described above, we can see that Base-8 MTP link, Base-12 MTP link and Base-24 MTP link have their own cons and prons. Base-8 MTP trunks allow users to build 10G links today but can easily be upgraded to 40G links tomorrow using 8 fiber MTP connectivity. Base-12 and Base-24 MTP trunks allow users to build 10G links today, which can easily be upgraded to 40G/100G links tomorrow using MTP conversion modules, MTP conversion harness or jumpers, but would result in 33% fiber wastage. MTP Links: Base-8 vs. Base-12 vs. Base-24: which is your choice?

Originally published: www.fiberopticshare.com/mtp-links-base-8-vs-base-12-vs-base-24.html

Related Post: MTP-8 Solution: Future-Proof Connectivity in Data Center

 

12-Fiber or 24-Fiber MTP/MPO Cabling: Which Is Better for 40G/100G Network?