Category Archives: XFP Transceivers

Why Not Use QSFP28 Transceiver for Your 100G Network?

Service providers and enterprise data centers are undergoing an infrastructure transformation to achieve higher levels of performance and scalability that may explain why the demand for 100G network is always on the rise. Optical transceiver, therefore, is usually considered to be a vital component to ensure the flexibility and reliability of the whole system. 100G transceivers have become a preferable alternative for those bandwidth-hungry applications in data centers to accelerate data flow. In this article, we will introduce several 100G transceivers which are commonly seen on the market. And emphasis will be put on the 100G QSFP28 transceiver.

Common 100G Transceivers Overview

There exist 100G CFP transceiver, CFP2 transceiver and CFP4 transceiver on the market. The CFP transceiver comes out firstly. It was designed just after SFP interface, but it is significantly larger to support 100 Gbit/s data rates. While the electrical connection of a CFP transceiver uses 10 x 10 Gbit/s lanes in each direction (RX, TX), the optical connection can support both 10 x 10 Gbit/s and 4 x 25 Gbit/s variants of 100 Gbit/s interconnects.

With improvements in technology, CFP2 and CFP4 specifications have appeared to allow higher performance and higher density. Having similar electrical connection with a CFP transceiver, CFP2 transceiver and CFP4 transceiver specify a form-factor of 1/2 and 1/4 respectively in size of a CFP transceiver. These three modules are not interchangeable, but would be inter-operable at the optical interface with appropriate connectors.

100G CFP CFP2 CFP4

100G QSFP28 Transceiver Description

And here comes the dominate 100G transceiver—100G QSFP28 transceiver, which is implemented with four 25 Gbit/s lanes. With an upgraded electrical interface, QSFP28 transceiver is capable of supporting signal rates up to 28 Gbit/s, thus making it as easy to deploy 100G networks as 10G networks. Moreover, it has a strong ability to increase density, decrease power consumption, and decrease price per bit. With QSFP28, the way to migrate to 100G can change from 10G-40G-100G to 10G-25G-100G or 10G-25G-50G-100G, which can largely simplify the cabling in data center and effective decrease the cable density and the cost.

Basically, there are two types of QSFP28 transceiver: QSFP28 SR4 for short range transmission up to 100 m and QSFP28 LR4 for long range transmission up to 10 km. The following diagram illustrate some detailed information of each type.

QSFP28 transceiver SR4 vs.LR4

QSFP28 SR QSFP28 LR
Fiber Type Multimode Single-mode
Reach 100 m over OM3; 125 m over OM4 10 km over SMF
Transmission Type Parallel MM (4x25G) CWDM (4x25G)
Wavelength(s) 4 x 850 nm 1295 nm-1309 nm
Application Data Centers Data Centers; Carriers
What Can We Benefit From QSFP28?

Giving a look back to the evolution of 100G modules in the past few years, all these changes are closely related to factors like power and cost, which matters a lot to every data center and server room. Thus, the reason why 100G QSFP28 emerges is partly explained. Then, what exactly can QSFP28 bring to us?

100G QSFP28

Higher Port Density: The first generation of 100G transceiver is CFP, which is very large. When it comes to CFP2 and CFP4, the next generation of 100G modules, their sizes decrease a lot. With the same footprint and face plate density as QSFP+, QSFP28 is even smaller than CFP4, and its high port density is also an overwhelming advantage. Generally, up to 36 QSFP28 can be installed on a 1RU switch on the front panel.

Lower Power Consumption: Compared with other 100G transceivers, QSFP28 requires the lowest power for transmission, which could be less than 3.5 W. While for other 100G transceivers, the power consumption ranges from 6 W to 24 W.

Lower Cost: QSFP28 is able to save considerable amount of money with higher port density and lower power consumption. In addition, QSFP28, implemented with four lanes, increases the transmission capacity of every lane from 10G to 25G, which can effectively decrease cost for each bit.

Conclusion

With higher port density, lower power consumption and lower cost, QSFP28 offers an optimum and feasible alternative for 100G network data transmission, especially for those large scale data centers and carriers. Hope this article could assist you in choosing the right transceiver to achieve smooth migration to 100G.

What Is 10G DWDM C-band Tunable XFP Module?

WDM (wavelength division multiplexing) technology, based on the concept of using multiple wavelengths of light on a single fiber, has been very popular in today’s data transmission. Dense WDM (DWDM) is one type of WDM which uses the C-Band transmission window with denser channel spacing. In a 10G DWDM network application, there are multiple transceiver choices for you. Among them, this article will introduce one option for you, DWDM C-band tunable XFP module.

Introduction

The tunable DWDM transceiver is a unique product which enables you to set the channel or “color” that the laser emits. This type of transceiver has been around for a number of years but it was not until 2008 that the first tuneable optics were available in the pluggable XFP form factor. Tunable transceivers are only available in DWDM form because the CWDM grid is too wide. Typically these tunable optics are for the C-Band 50GHz. Around 88 different channels can be set with intervals of 0.4nm, which is the 50GHz band. Tunable transceivers are typically used as “spare-optics”, in case of emergency, because you can tune them to the right channel and reduce the amount of spare optics you need to hold in stock.

DWDM tunable XFP 10 Gbps multiprotocol optical transceiver is an integrated fiber optic transceiver that provides a high-speed serial link of signaling rates. The module complies with the 10 Gigabit small form factor pluggable (XFP) multi-source agreement (MSA), and the ITU-T G.698.1 S-D100S1-2D standard. It features a hot-pluggable XFI-compliant electrical interface. DWDM tunable XFP transceiver integrates the receive and transmit path on one module. On the transmit side, the 10 Gbps serial data stream is recovered, retimed, and passed to a modulator driver. The modulator driver biases and modulates a C-band-tunable integrated laser, enabling data transmission over single-mode fiber through an industry-standard LC connector. On the receive side, the 10 Gbps optical data stream is recovered from an APD/transimpedance amplifier, retimed, and passed to an output driver. DWDM tunable XFP transceiver is designed to support full range of C-band ITU-T wavelength data rates from 9.95Gbps to 11.3Gbps and distances up to 80km. The image below shows a Cisco ONS-XC-10G-C compatible 10G DWDM C-band tunable XFP transceiver.

Cisco ONS-XC-10G-C Compatible 10G DWDM C-band Tunable XFP 50GHz 80km DOM Transceiver

Features of DWDM C-band Tunable XFP
  • XFI electrical interface compliant
  • Hot-pluggable XFP footprint
  • 80km MZM tunable TOSA
  • RoHS6 compliant
  • Client side and line side loopback functions
  • XFP MSA compliant form factor connector
  • Supports 50GHz ITU-based channel spacing (C-Band)
  • With wavelength locker function, wavelength precision about 0.02nm
Applications of DWDM C-band Tunable XFP

DWDM tunable XFP pluggable module allows enterprise companies and service providers to provide scalable and easy-to-deploy 10 Gigabit LAN, WAN, and Optical Transport Network (OTN) services in their networks. This module is a high performance and cost effective XFP transceiver module designed for 10G SDH/SONET, IEEE DWDM 10GBASE-ZR for 40 or 80 km reach (Ethernet), and DWDM 10G FC (Fibre Channel) for 40 or 80 km reach applications.

Conclusion

Fiberstore offers a variety of optical modules for extensive applications like telecommunication, datacommunication, and CWDM/DWDM network. Fiberstore’s DWDM C-band tunable XFP transceivers can be designed to be compatible with many major brands while delivering the deployment flexibility and inventory control. And Fiberstore provides a variety of industry standard from factors including SFP+, X2, XFP, SFP, like Avago AFBR-709SMZ compatible 10GBASE-SR/SW SFP+ and Allied Telesis AT-SPSX compatible 1000BASE-SX SFP transceivers, which can make the customers satisfied with the broad choices and high performance.