2017-12-19

What Is 25G Gigabit Ethernet and Its Advantages

The well-known Ethernet upgrade path is 10G-40G-100G. However, a new research report shows that the latest server upgrade path will be 10G-25G-100G, and it can be upgraded to 400G in the future. But why is it 25G? Because it is a big jump from 10G to 40G, and the fact is that the incremental cost of upgrading from 10G to 25G are not high. We need to support this new Ethernet rate with upgraded cable and optical modules, which will undoubtedly drive the development of QSFP28 and SFP28 optical modules.

An Emerging Standard - 25GbE


In July 2014, 25G Gigabit Ethernet (25GbE) passed the first level of the IEEE agency and successfully completed the Intent Call (CFI). 25G Ethernet is a recommended new Ethernet standard for cloud computing and enterprise data centers. The 25GbE uses four optical fibers in parallel with paired copper cables to achieve a 100G Ethernet transfer rate over four 25-Gbit / s lanes.

Why to Select 25G Gigabit Ethernet?


Compared to the existing 40G standard, 25GbE technology value has been very clear. The 25GbE provides greater port density and lower unit costs for rack server bandwidth connections. For the applications requiring high end-of-line throughput, 25G uses two lanes to 50G compared to four lanes to achieve 40, which is a better choice both for connectivity and physical channel efficiency.

The 25GbE standard uses biaxial copper cables and provides up to 2.5x faster performance per SerDes channel over the existing 10G and 40G. The 50G Ethernet connection uses two switches or network card SerDes channels running at 25 Gb / s, delivering 25% more bandwidth than the 40G and using only four biaxial copper cables, half the 40G. With a single switch / network card SerDes channel, the 25GbE connection provides 2.5 times the 10GbE bandwidth using the same number of SFP + Direct Attach Cables (DAC).

The biggest benefit that 25GbE technology brings to data center operators is the ability to maximize bandwidth and port density with 1U of panel space. It can also implement 100GbE with 25Gb / s single physical layer technology.



25G Ethernet Drives the Development of QSFP28 and SFP28 Optical Modules


QSFP28 applies to 4x25GE access ports and SFP28 for a single 25GE access port. SFP28 module, based on SFP + package, supports 25G Ethernet standard. The SFP28 delivers 25Gb / s transmission with up to 100 meters in over four types of multimode fiber without error code and can be used in high-density 25G Ethernet switches and network interfaces to facilitate data center server connectivity. It applies the popular SFP+ form factor, offering enterprises a more cost-effective solution to upgrade 10G Ethernet connectivity.

QSFP28 (25G Quad Small Form-factor Pluggable) module and interconnect cable are high-density, high-speed product solutions, which is designed for optical communication, data center and networking market applications. It provides four high-rate signaling channels that can grow from 25Gbps to 40Gbps and will meet the 4X wireless bandwidth-enhanced data rate (EDR) requirements of 100 Gbps Ethernet (4x25 Gbps).

The below photo is the QSFP28 100GBASE-SR4 by Gigalight. The QSFP28 SR4 optical module is a vertically integrated solution that meets the IEEE802.3 standard and MSA requirements while power consumption is significantly lower than 2.5W. This module supports breakthrough applications of the 100GBASE-SR4 standard and IEEE 802.3bm.


 Conclusion


25G will be the dominant next-generation server connection speed standard because it offers mainstream customers a long-term cost advantage. Compared to the existing 40G standard, 25GbE technology value has been very clear. The 25GbE provides greater port density and lower unit costs for rack server bandwidth connections. For applications requiring high end-of-line throughput, 25G uses two lanes to 50G compared to four lanes to achieve 40, which is a better choice both for connectivity and physical channel efficiency.


2017-12-12

Types and Standards of 100G Optical Transceivers

As people demand higher and higher bandwidth, 100G networks has been developed rapidly. 100G optical module is an important part of 100G network. Now, there are several important standards and types of 100G optical transceivers. This post will introduce the related knowledge of 100G optical module in detail.

Types of 100G Optical Transceivers


The form factors of 100G optical transceivers mainly include: CFP, CFP2, CFP4 and QSFP28. To compare their advantages, the main factor to consider is the data center costs and power consumption.

1. CFP optical transceiver supports all C-band wavelengths tunable. It is able to complete the link detection by using a common optical dual binary modulation format ODB. The power consumption is less than 24W.

2. The volume of CFP2 optical module is one-half the CFP, whose integration is 2 times of CFP. It can complete the wide dynamic input range based on SOA to achieve stable admission sensitivity. It supports a full CFP optical module and its low power consumption is lower than 9W.

3. The volume of CFP4 optical transceiver is one-half the CFP2’s, its integration is twice that of CFP2. The front panel port density is also doubled compared with CFP2. CFP4 optical module MSA protocol supports the same rate of CFP2 and CFP2s. The transmission power has increased significantly, but the power consumption has dropped significantly, only about half of the original, the system cost is lower than the CFP2. In addition, CFP4 optical module select 4 * 25 form, through the 425G channel to complete 100G transmission, higher transmission power, more stable.

4. QSFP28 optical transceiver module form factor style is smaller than the CFP4 optical module. QSFP28 optical module power consumption is generally not more than 3.5W; the use of QSFP28 optical module can directly upgrade through the 40G to 100G, the cost is lower. There are all kinds of 100G QSFP28 optical transceivers in the market, like QSFP28 100GBASE-CWDM4, QSFP28 100GBASE-PSM4, QSFP28 100GBASE-SR4, and QSFP28 100GBASE-LR4, etc.



100G Optical Transceiver Standard


Since the coming of 100G networks, IEEE, Multi-SAource Agreement (MSA) industry alliances and other agencies have formulated a number of standards for 100G optical modules. Among the many standards, the PSM4 and CWDM4 standards are developed by the Multi-Source Agreement (MSA) industry group, which are more suitable for the mainstream 100G QSFP28 optical modules on the market today. The following table is the specific circumstances of some common 100G optical transceiver standard:


Note:

The 100G PSM4 standard is introduced primarily to reduce the cost of expensive 100GBASE-LR4 optical modules. The 100G PSM4 optical transceiver is a single-mode, parallel, four-channel optical module designed for applications in the data center of 500 meters.

The 100G CWDM4 standard is mainly formulated for the deployment of a 2km 100G link in a data center. The interface of a 100G CWDM4 optical transceiver conforms to the 2km 100G optical interface specification of duplex single mode optical fiber, and the transmission distance can reach 2km.

2017-12-04

An Introduction of 4 Types of 100G QSFP28 Optical Transceivers

The continual rapid development of Internet and people’s desire for more high-speed optical networks promoted the development of the whole optical communication industry. Meanwhile, they strongly promoted the independent R&D and innovation breakthrough of many core technologies including optoelectronic devices technology. 100G optical transceivers are products of the big data era. According to authorities, by 2018, there will be 38% of service providers deploying 100G networks in the whole world, which means the 100G era has arrived.

Therefore, 100G optical transceivers are quite important in the optical networks, in which 100G QSFP28 optical transceivers are regarded as one of the most popular 100G optical transceivers in the current market. In the post, we will introduce you 4 types of 100G QSFP28 optical transceivers that may be helpful for your needs.

1. 100G QSFP28 CWDM4 2KM Optical Transceiver


100G QSFP28 CWDM4 2KM optical transceiver is a 100Gb/s transceiver module which is designed for optical communication applications compliant with the QSFP MSA,CWDM4 MSA and portions of IEEE P802.3bm standard. The optical transceiver module converts 4 input channels of 25Gb/s electrical data to 4 channels of CWDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission. On the contrary, the module de-multiplexes a 100Gb/s optical input into 4 channels of CWDM optical signals and then converts them to 4 output channels of electrical data on the receiver side. The product provides superior performance for 100G Ethernet applications up to 2km links.

2. 100G QSFP28 PSM4 2KM Optical Transceiver


100G QSFP28 PSM4 2KM optical transceiver is a four-channel, pluggable, parallel, fiber-optic QSFP28 PSM4 optical transceiver module for 100/40 Gigabit Ethernet and Infiniband DDR/EDR Applications. This optical transceiver integrates four data lanes in each direction with 104 Gbps bandwidth. Each lane can operate at 26Gbps up to 2km by using G.652 SMF. The optical transceiver module is designed to operate over single mode fiber system using a nominal wavelength of 1310nm. The electrical interface uses a 38PIN Edge type connector. The optical interface uses a single mode 12 fiber MTP (MPO) connector. The outstanding circuit and optical technology by Gigalight provide reliable long life, high performance, and consistent service.

3. 100G QSFP28 LR4 10KM Optical Transceiver


The 100G QSFP28 LR4 optical transceiver module is a 100Gb/s transceiver module designed for optical communication applications compliant to 100GBASE-LR4 of the IEEE P802.3ba standard.
The module converts 4 input channels of 25Gb/s electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission. Its 100Gb/s high sensitivity PIN receivers provide superior performance for 100Gigabit Ethernet and OUT4 applications up to 10km links and compliant to optical interface with IEEE802.3ba 88 100GBASE-LR4 requirements. The product design and form factor, light/electrical connections and digital diagnostic interfaces are all based on QSFP+MSA protocol.

4. 100G QSFP28 SR4 Optical Transceiver


The 100G QSFP28 SR4 optical transceiver is a four-channel, pluggable, parallel, fiber-optic QSFP+ SR4 optical transceiver module for 100/40 Gigabit Ethernet, Infiniband DDR/EDR and 32GFC applications. This transceiver is a high performance module for short-range multi-lane data communication and interconnects applications. It integrates 4 data lanes in each direction with 112.2 Gbps bandwidth. Each lane can operate at 8.055Gbps up to 70M using OM3 fiber or 100M using OM4 fiber. The module is designed to operate over multimode fiber system using a nominal wavelength of 850nm. The electrical interface uses a 38 contact edge type connector. The optical interface uses an 12 fiber MTP (MPO) connector.


In above, 100G QSFP28 optical transceiver modules have huge market prospect that are better suited for high-density cabling and widely favored by most data centers. And the 4 types of 100G QSFP28 optical transceiver modules are all launched by Gigalight. If you want to get more information, please visit Gigalight official website.