#base-8 system

Since the introduction of Base-12 connectivity in the mid 1990s, the 12-fiber MTP/MPO connector and Base-12 connectivity have served the data center for about twenty years. It has helped a lot in achieving high-density and manageable cabling. Recently, many documents and posts are discussing about a new technology—Base-8. Its appearance is regarded as the evident need of future networks. Even though most of the words are promoting the overwhelming advantages of Base-8 system, we should still consider the defects and merits of these two systems based on some facts before taking the next step by ourselves. This post is a discussion on this topic.

Facts of Base-12 and Base-8

In this part, the design features of Base-12 and Base-8 systems will be introduced. And their dominant advantages are going to be discussed too.

Design Features

Base-12 connectivity makes use of links based on groups of 12, with 12-fiber connectors such as the MTP. In Base-12 connectivity, for example, trunk cables have fiber counts that are divisible by number 12, like 24-fiber trunk cable, 48-fiber trunk cable and all the way up to 144 fibers. However, in a Base-8 system, we don’t have 12-fiber trunk cable, instead we have 8-fiber trunk cable, 16-fiber trunk cable, 32-fiber trunk cable and so on. All trunk cables are based on increments of 8 fibers.

Base-12 and Base-8 trunk cables are visually different on connector design. A Base-12 trunk cable generally has unpinned (female) connectors on both ends and demands the use of pinned breakout modules. In the new emerging Base-8 system, a trunk cable is designed with pinned (male) connectors, as a result, it should be connected to unpinned components.

Figure: Unpinned and Pinned Connectors

Comparison

Compared with Base-8, Base-12 obviously has the benefit of higher connector fiber density. Thus a larger number of fibers can be installed more quickly when using Base-12 connectivity. And it is very easy to be deployed into all-ready existing Base-12 architecture. As the networks are migrating to 40G and 100G data speeds, Base-8 connectivity has some advantages that cannot be denied. For some 40G and 100G applications, including SR4 (40G and 100G over parallel MMF) and PSM4 (100G over parallel SMF) supported eight-fiber transceivers, and SAN switch Base-8/Base-16 port arrangements, Base-8 connectivity is a more cost-effective choice. In these applications, Base-8 enables full fiber utilization for eight-fiber transceiver systems. But Base-8 connectivity is not optimized for all situations, including duplex protocols like 25G and 100G (duplex SMF).

Correct Co-existence of Base-8 and Base-12

If we are going to deploy Base-8 devices in our existing network, it is possible to have Base-12 and Base-8 connectivity at the same time as long as we do not mix them in the same link. On one hand, it is not wise to use conversion module between Base-12 and Base-8 devices, because the added cost and increased insertion loss will surpass the benefits it can brought. As mentioned before, the two systems are not interchangeable since they usually have different connector configurations and have unequal attachment requirements. Therefore, special care should be given when managing the data canter physical layer infrastructure, to ensure that the Base-12 and Base-8 components are used separately.

Conclusion

When a new technology comes out as a new option for us, we need to decide whether to change or not. In terms of the discussion on Base-12 and Base-8 systems, after listening to voices from different sides, the key factors are still determined by own specific needs. If we decided to move to the new technology, the following question is how to realize the best migration. Having comprehensive understanding of the solutions and products vendors supply will never be a bad choice.