Everything You Should Know About 40GBASE-T Network

Data center network transmission speed is getting higher and higher, before everyone used 10G, but now many places are starting to use 40G. Although fiber is very strong, but many people still eye on the copper cable, especially Cat8. why? Because it's cheap, easy to install, and backward compatible. Then what is 40GBASE-T and Cat8 is not a must? This article will talk about these things.

40G Ethernet Physical Layer Alternatives

40G Ethernet now actually has a lot of programs, mainly depends on how far you want to go, how much the budget, there is no ready-made equipment. A few common connections are probably like this: Single-mode fiber: long distance, but expensive Used to pull a very long link, such as 40 kilometers kind. Common is 40GBASE-ER4, four channels, each running 10G, together 40G. suitable for budget is sufficient, or need long-distance transmission scene. Multimode fiber: cheaper, suitable for medium distance MPO interface multimode fiber is now used more, such as 40GBASE-SR4. OM3 fiber up to 100 meters, OM4 about 125 meters, the cost is lower than the single-mode, quite suitable for data centers to connect between racks. Twinax copper: the most cost-effective for ultra-short distances 40GBASE-CR4 standard recommended Twinax, transmission distance of no more than 7 meters. That is, when the equipment is very close to each other, such as switches and servers in the same rack, you can use this. Twisted Pair: The main event of the day - Cat8! This is the true meaning of “40GBASE-T”. Although it is not yet as popular as 10GBASE-T, but the momentum is good. Copper is cheap, easy to deploy, and most importantly - backwards compatible. Any device you originally used with 10G can be connected.

What is 40GBASE-T and How Does It Relate to 25G?

IEEE started working on the 40GBASE-T standard back in 2012, and then 25G was pulled in. Now both are under IEEE 802.3bq. 25GBASE-T: The speed is 25Gbps over four twisted pairs, which is kind of like 10GBASE-T, but faster. Can also negotiate speed reductions with 10G devices. 40GBASE-T: Goes even further than 25G, running at 40G Ethernet, also on four pairs of wires, but with much higher frequency requirements and harder interference. So you have to use Cat8 wires with higher performance. These two standards are kind of “brothers” in the sense that they share a lot of infrastructure, and Cat8 cables can support both of them without any problem.

What are Cat 8 Cables?

Category (Cat8) is the next generation twisted-pair copper cable standard designed by ANSI/TIA-568-C.2-1 in 2016. The Cat8 supports up to 2 GHz bandwidth. Compared with the previous generation, the Cat8 cable has higher bandwidth and requires shielding. Cat 8 cable can transmit up to 30m in a dual connector configuration. Its connectors can be either Class I (RJ45) or Class II (non-RJ45). Cat 8 cable supports backward compatibility with all RJ45 cabling and devices, and it is designed to support 25GBASE-T and 40GBASE-T applications. The Cat8 Ethernet cable is more common for interconnections between switches and servers in the data center.

Note: Although Cat8 uses RJ45 headers, there are some high-end versions that use non-RJ45 Class II connectors, and RJ45 is still used in common scenarios.

Why Do We Choose Cat8 Cable for 25G/40GBASE-T Network?

25/40G Ethernet still has broad development prospects in the current data center, and they are generally used for server interconnection. In 25 or 40G network deployment, the more common wiring systems include DAC components, OM3, OM4, and other optical cables. But these devices all have certain defects, such as the Twinax DAC assembly can only link the distance between devices less than 5m. Optical cables need to be used together with other equipment, such as optical transceivers. When the optical fiber link is less than 30m, the use of optical cables will increase the cost of the wiring system. The following section will describe the advantages of using Cat8 cable for 25G/40GBASE-T networks.

Easy Migrations to Higher Bandwidth

As we mentioned earlier, the patch cords can use the same RJ45 interface between them, so network upgrades can be implemented one end at a time. As a result, Using Cat8 patch cords allows data centers to quickly and smoothly migrate networks from 1G to 10G, 25G, and 40G incrementally.

Simple Deployment

Cat8 cable is plug-and-play and part of the BASE-T system, it is also very easy to terminate in the field, which saves engineers a lot of effort and time costs.

Cost Saving

The most outstanding advantage of copper transmission is that it can save a lot of money, and the twisted pair copper cable system has always been the most cost-effective solution in Ethernet networks. When you need to deploy a 25/40GBASE-T network, and the transmission distance is less than 30m, you can choose the fiber optic cable system and the Cat 8 cable system, and the Cat 8 cable has a lower cost. When the transmission distance is less than 5m, using the Cat 8 cables costs less than Twinax. Similarly, 25/40GBASE-T using a fiber optic system requires additional optical module hardware, which brings more deployment costs. The maximum transmission distance of Category 8 cable is 30 meters. In practical applications, less power is required. What's more? 25/40GBASE-T network using Cat 8 cable has lower thermal power, and the enterprise management network has less cooling pressure to further help enterprises reduce costs.

At last, is Cat8 suitable for all 40G scenarios? Not really. If you are trying to pull links across floors or even across campuses, Cat8 is definitely not enough and is still more suitable for using fiber. If you are just interconnecting equipment in the server room, with a distance of no more than 30 meters, then Cat8 is really cost-effective.

Conclusion

Data centers have been seeking higher bandwidth and components that can carry higher network speeds to cope with increasing network demands. Cat8 cables are gaining more and more attention in 25/40GBASE-T networks, and they can help data centers upgrade to 25G/40GBASE-T networks with less cost. If you need Cat8 patch cables or get more information about Cat8 patch cables, please contact QSFPTEK via [email protected].