Tag: QSFP-40G-CSR4

40G and 100G Pluggable Optics in Data Center

In order to meet the demand for increased network bandwidth, migration to 40G Ethernet links for switch to server and storage area network connections in data centers and 100G Ethernet links for core switching and routing connections in the backbone is the trend.

The requirement for higher data rates is being driven by many factors. Switching and routing, virtualization, convergence and high-performance computing environments are examples of where these higher network speeds will be required within the data center environment. Additionally, Internet exchanges and service provider peering points and high-bandwidth applications, such as video-on-demand, will drive the need for a migration from 10- to 40- and 100-Gbit interfaces.

40G Pluggable Optics

There is various ideal equipment for 40 Gigabit Ethernet applications, such as cables, transceivers, connectors and switches for 40G transmission. For instance, OM3 and OM4 multimode fibers are widely used in 40 Gigabit applications especially in data centers. These cables have lower cost than singlemode fibers, for they can avoid higher costs created by single-mode laser source. The transceivers connected by cables is at the center of the 40 Gigabit Ethernet network layer. They are usually connected by OM3 or OM4 fibers and can be plugged into a variety of components including interface cards and switches or network servers. The common types of 40G transceivers are C Form-factor Pluggable (CFP) transceivers, and Quad Small-Form Pluggable (QSFP) transceivers. For example, Cisco QSFP-40G-CSR4 compatible QSFP+ transceiver supports link lengths of 82m, 300m and 400m, respectively, on OM2, OM3 and OM4 multimode fibers at a wavelength of 850nm.

JG325B

100G Pluggable Optics

100G is ready here. Tens of thousands of 100G Ethernet links deployed in core routers and carrier switches. Vast majority are CFP modules and CFP2 deployments are now starting. In addition,100G is rapidly expanding. For instance, new optical standards for the data center (100G SR4, CWDM4, PSM4) and new higher density 100G module form factors like CFP4 and QSFP28 are on the way. High port-count 100G switches are being designed and many 100G modules will be used to support high-density 10G and 25G. It is said that 100G and 4x 25G deployments are expected to grow substantially starting in 2015. 100G products mainly include 100GBASE-SR10 and 100GBASE-LR4 CFP/CFP2/CFP4 and 120G AOCs. Additionally, QSFP28 as the 100G module form factor of choice for new data center switches is also launched.

40G vs. 100G in the Data Center

The most direct difference of 40G and 100G optics is the data rate. But actually, 40G and 100G optics have their own merits.

Characteristic of 40G Pluggable Optics

  • Lowest cost per bit
  • MMF reaches up to 300 m
  • Breaks out to 4 x 10G

Characteristic of 100G Pluggable Optics

  • Highest density per bit
  • Lowest power consumption
  • MMF reaches up to 100m for now
  • Breaks out to 4 x 25GE
Conclusion

Content and application growth is driving the growth in bandwidth and traffic as well as growth in optical links. 40G and 100G optics developments are supporting the growth in traffic with smaller module form factors for higher port density with lower power consumption and lower cost per bit. Meanwhile, new link speeds like 25G, 50G, 200G and 400G are being standardized. The pluggable optics will continue to develop to further satisfy the changing requirements in data center.

QSFP Transceiver – a Hot-pluggable Transceiver With High Density

As a new Multi-Source Agreement (MSA) for high speed applications such as 40G-BASE, QSFP transceiver, which is one kind of 40G transceiver, can provide four channels of data in one pluggable interface. Each channel is capable of transferring data at 10Gbps and supports a total of 40Gbps. Compared with standard SFP+ modules, QSFP transceiver is with higher density and lower cost. It is designed to enable extremely high-density applications with stacked and ganged configurations.

Advantages of QSFP Transceiver

Since the QSFP transceiver integrates four ultra-high capacity, independent fiber transmit and receive channels, its port density is increased and the total system cost is declined. Actually, its port density is of three times higher than the traditional SFP transceiver, enabling the QSFP to be used to replace four standard SFP modules in space that is only 30 percent larger than a single SFP. In addition, the QSFP transceiver can support Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with data rates up to 5Gb/s per channel. Thus the QSFP platform demonstrates potential for aggregated higher volumes and improved economics realized from several protocols/applications using the same transceiver.

Classifications of QSFP Transceiver

There are various kinds of QSFP transceivers for different distance requirements and fiber types. According to various criteria, QSFP transceivers can be classified into different categories.

  • Classified by Transport Media

Copper, single mode fiber (SMF) and multimode fiber (MMF) are three kinds of transport media used in 40 Gigabit Ethernet. Different QSFP transceivers may adopt different transport media. According to IEEE Ethernet standard, the followings are commonly used 40 Gigabit Ethernet media system:

QSFP-40G-CR4—40 Gigabit Ethernet over four short-range twinaxial copper cables bundled as a single cable.

QSFP-40G-SR4—40 Gigabit Ethernet over four short-range multimode fiber optical cables.

QSFP-40G-LR4—40 Gigabit Ethernet over four wavelengths carried by a single long-distance single mode fiber optical cable.

QSFP-40G-SR4

QSFP transceiver

  • Classified by Connector Type

Different QSFP transceivers may have different connector interfaces. Through various technologies, many kinds of connectors could be applied into 40 Gigabit Ethernet. And the commonly-used are Duplex LC, MPO and MPO/MTP. MPO and MTP are often used interchangeably. For example, the aforesaid QSFP-40G-SR4 and QSFP-40G-LR4 are transceivers with Duplex LC connectors. While the Cisco QSFP-40G-CSR4 is with MPO/MTP connector.

  • Classified by Transmission Distance

According to transmission distance, QSFP transceivers can be divided into short-range QSFP transceiver and long-range QSFP transceiver. QSFP-40GBD-SR is among the various short-range QSFP transceivers. It supports link lengths of 100 meters and 150 meters over laser-optimized OM3 and OM4 multi-mode fibers respectively. As a long-range QSFP transceiver, QSFP-40G-ER4 has a transmission distance of 40 km.

  • Classified by Wavelength

In a QSFP transceiver, the wavelength of each channel can either be of the same or differs from each other. For instance, The wavelengths of Cisco QSFP-40G-SR4 and Cisco QSFP-40G-CSR4 transceivers are 4×850nm. While the four lanes of QSFP-40G-ER4 are 1271nm, 1291nm, 1311nm and 1331nm respectively.

40 Gigabit Ethernet is really a hot topic in recent years. Accordingly, different kinds of QSFP transceivers are springing up all over the world. As a leading optical network products supplier, Fiberstore supports a full range of both direct attach cables and optical transceivers for 40 Gigabit Ethernet.