Showing posts with label 40G DAC. Show all posts
Showing posts with label 40G DAC. Show all posts

Wednesday, March 30, 2016

The Reality of Copper and Fiber Cable

The war between copper and fiber has been raged for years and it is never ended. Copper-based systems maintain the same upgrade path that they have for years, while fiber-optic proponents continue to advocate their sense of superiority, which forces people to face the dilemma of selecting copper or optical fiber. So, once again, which cabling type is the best overall value for their current and projected future needs? This article carefully looks into the question and gives you the reality of the present copper and fiber cables.

Major Difference Between Copper and Optical Fiber
Cable length and data rates are two of the key criteria that differentiate the use of copper or fiber optic cable. If you require a long link length and high data rate, then fiber cable may be the obvious choice, and you can move on to selecting a specific fiber cable. Alternatively, if the runs are short and the data volume fits within copper's capacity, then copper it is. Some other general differences between copper and fiber optic cables are offered in the table. Once you understand the distinct properties of copper and fiber, your solution may seem clearer. Now let’s come to the reality of both cables to help you select the suitable one.

difference between copper and fiber cable

Copper Cabling in Gigabit Ethernet Application
Category 6 or Cat6 data cabling as one of the most popular copper cables in the market today, has been utilized for Gigabit Ethernet and several other network protocols. As the sixth generation Ethernet cables formed from twisted pairs of copper wiring, cat6 is composed of four pairs of wires, similar to cat5 cables. The primary difference between the two, though, is that cat6 makes full use of all four pairs. This is why cat6 can support communications at more than twice the speed of cat5e, allowing for Gigabit Ethernet speeds of up to 1 gigabit per second.

copper cabling

However, there are some link restrictions in using this type of data cabling. When used for 10/100/1000BASE-T, the restriction of the copper cable is 100 meters, and when used for 10GBASE-T, the restriction is 55 meters. Another issue is that there are some cat6 cables that are very large and are quite difficult to connect to 8P8C connectors (a type of modular connector used for communications purposes such as phone/Ethernet jacks) when the user does not have a unique modular piece.
Copper cable still has a place in the telecom field, the best prove is that copper cable has improved itself to face the ever-increasing bandwidth requirement. For 40G Ethernet, there are 40G DAC cables — passive copper cable or active copper cable available in the market to achieve 40G connectivity. For example, Cisco QSFP to QSFP+ copper cables, like QSFP-H40G-CU1M and QSFP-H40G-ACU7M are widely used to connect within racks and across adjacent racks.

Fiber Optic Cabling
Fiber optic cable is completely unique from cat6 and other types of copper cabling systems. The most obvious feature about optical fiber is that it draws on light instead of electricity to transmit signals. In addition, optical fiber is immune to electrical interference, which means that a user can run it just about anywhere, anytime. However, fiber is not that easy to install. Terminating fiber optic cable is not as simple as copper. While manufacturers have developed crimp-on connectors, they are expensive, high loss and have not been very reliable. Fiber optic connectors need adhesives for reliability and low cost. And most installation involves stripping fibers, injecting adhesives and polishing the ends. No IDC (insulation displacement connectors) here. Any good installer can learn how to terminate fiber in less than 2 hours. The following picture shows a singlemode and multiomde optic cable.

singlemode and multimode optic cable

Not all fibers have infinite bandwidth. At least not the multimode fiber used in most premises networks. It's a lot higher than copper, but as you approach gigabit speeds, you are limiting the distances available for links to 500 meters or so. Singlemode fiber, as used in telecom and CATV networks, practically has infinite bandwidth. But it uses higher cost components and can be pricey for shorter links. It's not necessary for today's networks but may be for the next generation. Well, fiber prices continue to fall while copper prices rise.

Know Your Application, Then Select Your Cable
Just as knowing it’s vital to select the right switches, routers and firewalls for an industrial Ethernet network, it is also vital to select the right cable. When it comes to industrial Ethernet cable, long reach and high data volumes call for fiber cable. For short runs and average data requirements, copper cable will do the job. Next consider the operating environment and mechanical devices will face to help you on a final choice. Fiberstore provides various copper cables and fiber cables, including OM3 cable, OM4 cable, Cat6A copper cable, Cat5A copper cable and other specific cables. 40G DACs and AOCs are also offered. You won;t miss it.

Thursday, January 7, 2016

Introduction to 25G and 40G Ethernet Network

When you look at the evolution of networking and the data that drives it, there is no surprise that Ethernet has been and will continue to be the most widely used network interface. Consumers and network designers wish to smoothly migrate to higher network speed—100G/400G without compromising quality. Ethernet speed upgrade path was clearly defined as from 10G,40G to 100G. But recently a new migrate path (10G-25G-100G) was gradually accepted by subscribers. For those who need to migrate their network to adopt to the big data age, choose 25G or 40G Ethernet, that is the question! This article provides the pros and cons of 25G and 40G Ethernet network. You will get your own answer at the end of it.
25G or 40G
Here Comes 25 Gigabit Ethernet
25 Gigabit Ethernet has passed the first hurdle in the IEEE standards body with a successful Call for Interest (CFI) in July, 2014. It is a proposed standard for Ethernet connectivity that will benefit cloud and enterprise data center environments. 25 GbE leverages technology defined for 100 Gigabit Ethernet implemented as four 25 Gbit/s lanes (IEEE 802.3bj) running on four fibers or copper pairs. Telecom giants like Google, Microsoft, Arista, and Mellanox are pushing the development of a 25 Gigabit Ethernet standard for top-of-tack server networking. Relevant transceiver modules and optical cables are developed to support this technology.
40G Ethernet Network
The IEEE P802.3ba 40G and 100G Ethernet Task Force was formed to develop a 40 Gigabit Ethernet and 100 Gigabit Ethernet draft standard. At the physical layer, 40G Ethernet is essentially 4×10G lanes. Standards-based 40G Ethernet switches and routers are starting to show up in enterprise networks, following ratification of the IEEE 802.3ba specification in mid-2010. QSFP+ modules and 40G DAC cables are introduced to back 40G networking, which are warmly welcomed by network designers. For example, QSFPP-4X10GE-LR (see in Figure 2) is compatible Juniper QSFP+ transceiver. It can be used in a 4×10G modules with 10GBASE-LR interfaces.
Juniper QSFPP-4X10GE-LR
25 Gigabit or 40 Gigabit Ethernet for Your Server
The most obvious feature of 25 Gigabit is described in two words—single lane. The phrase refers to the electrical signaling on the chip that would power an Ethernet port, while the design of 40 GbE was based on 10 GbE. Originally, 100 GbE had a similar heritage, with its initial design in 2010 using 10 lanes of 10 Gbps. This is the first generation of 100G transport links. As standards bodies sought to improve the efficiency of 100 GbE in the coming years, its second generation consists of four lanes of 25 Gbit/s Ethernet on four fiber or copper pairs. This will be disruptive to the 10G and 40G infrastructure.
In addition, the proposed 25 GbE standard reduces the number of lanes on the chip makes it less expensive to produce and less power-hungry. It also simplifies the process with just minor changes for forward error correction and lane alignment when compared to 40 GbE. To sum up, getting 25 GbE performance for the same price of 10G combined with reduced operating costs, which makes itself a compelling proposal for migration.
On the other hand, driven by cloud computing, mobile broad-band and IPTV for higher user bandwidth, demand for 40G transport links is growing quickly. 40G links has been deployed for more than 5 years. Compared to 25GbE, it has a longer history. And a good news is that advances in semiconductor technology and innovative designs are reducing the cost of 40G systems. High-speed serial links, flexible interfaces, integrated packet, lower power and less silicon real estate are all helping telecom manufacturers deliver cost-effective solution to upgrade from 10G to 40G.
The 40GbE specification defines a wide range of port types and has been ratified by IEEE. 40G optical equipment are all compatible with the existing 10G devices. Take 40G-QSFP-4SFP-C-0101 (see in Figure 3) as an example, it is the compatible Brocade QSFP+ to 4SFP+ Passive Breakout Copper Cable, which offer a cost-effective way to establish a 40G link between QSFP port and SFP+ within racks and across adjacent racks. However, 25GbE transceiver modules like QSFP28 and SFP28 will not be compatible with the existing QSFP+ and SFP+ cable assemblies. Which will cause trouble to users. Many experts believe that if people agree to add 40GbE instead of endlessly debating will lead to faster standards completion.
Brocade 40G-QSFP-4SFP-C-0101
Right Move at the Right Time
Planning for migration to higher-speed Ethernet can feel daunting as telecom experts hold different opinions towards the future of 25G and 40G. Some believe that the dominant next-generation server connection speed is going to be 25G, but some confirm that 40G between switches is expected to remain and will not be affected by this development. Just remember to make the right move at the right time. Fiberstore is working on providing cost competitive longer reach option for mainstream customers. We are very glad to offer our expertise in choosing the physical infrastructure that best meets your needs.