Types of QSFP Transceivers

In order to meet the demand for increasing the transceiver port density for optical applications and find a cost effective way to increase date rate, multiple communications companies announced the release of a quad small form-factor pluggable (QSFP) optical module specification in its final form in December 4, 2006. The QSFP specification defines a highly integrated four-channel optical transceiver to provide increased port density and total system cost savings when replacing four standard SFP transceiver modules. The 40GBASE QSFP module has become a dominant 40G optical transceiver and offers customers a wide variety of high-density 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications.

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

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.

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, Fiberstore QSFP-40G-SR4 and QSFP-40G-LR4 are transceivers with duplex LC connectors. While the Cisco QSFP-40G-CSR4 is with MPO/MTP connector.

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.

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.

The QSFP specification accommodates Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. The QSFP transceiver modules can be connected to both copper and optical cables. In the process of transmitting data,the QSFP transceiver converts parallel electrical input signals into parallel optical signals by a driven Vertical Cavity Surface Emitting Laser (VCSEL) array. All data signals are differential and the data rate can be up to 10 Gbps per channel. As the QSFP transceivers are used to interface networking hardware to a fiber optic cable, the choice of them depends on many factors, like the transport media, the connector type, transmission distance, wavelength, etc.

Things You Need to Know About Direct Attach Cables

A direct attach cable (DAC) is a fixed assembly that is purchased at a given length, with the connector modules permanently attached to each end of the cable. The direct attach cable is designed to use the same port as an optical transceiver, but compared with optical transceivers, the connector modules attached to the DAC leave out the expensive optical lasers and other electronic components, thus achieving significant cost savings and power savings in short reach applications.

Types of DAC

The direct attach cable can be divided into different types according to different criteria. According to the cables used, the direct attach cables include copper cable assemblies and fiber optic cable assemblies. Besides, DAC cable assemblies can also be classified into 10G SFP+ cables, 40G QSFP+ cables, and 120G CXP cables according to the data rate supported by different connector modules.

What’s more, we can also divide the DAC according to the number of connectors on the end of the cable. Most DAC assemblies have one connector on each end of the cable. But there is a special kind of DAC assembly which may have 3 or 4 connectors on one end of the cable. For instance, Cisco QSFP-4SFP10G-CU1M compatible QSFP+ to 4SFP+ passive breakout copper cable from Fiberstore has a single QSFP + module rated for 40-Gbps on one end and four SFP + modules, each rated for 10-Gbps, on the other end.

Direct Attach Copper Cable vs. Active Optical Cable

Direct attach copper cable is interchangeable and hot swappable with fiber optic modules. It supports such multiple protocols as Gigabit & 10G Ethernet, 8G FC, FCoE and InfiniBand, direct attach copper cable is a cost effective solution over optical transceivers. The defect of direct attach copper cable is that it is heavy and bulky, making it difficult to be managed. Furthermore, due to the nature of electrical signals, direct attach copper cable is vulnerable to the effects of electromagnetic interference (EMI), such as undesirable responses, degradation, or complete system failure.

Since the optical fiber is a kind of dielectric (not able to conduct electric current), AOC is also immune to EMI. Compared with direct attach copper cable, the drawback of AOC is that it may be a little expensive for customers. With the benefits of AOCs, such as lighter weight, high performance, low power consumption, low interconnection loss, EMI immunity, AOCs are now considered as the rising star of in telecommunications. For example, QSFP-4X10G-AOC10M from Fiberstore is suitable for very short distances and offers a very cost-effective way to establish a 40-gigabit link between QSFP ports of Cisco switches within racks and across adjacent racks.

Fiberstore DAC Solutions

Fiberstore offers a variety of high speed interconnect DAC assemblies including 10G SFP+ cables, 40G QSFP+ cables, and 120G CXP cables to satisfy the demands from 10G to 100G interconnection. All of the Fiberstore’s direct attach cables can meet the ever growing need to cost-effectively deliver more bandwidth, and they can also be customized to meet different requirements.

10 Gigabit Ethernet Cabling Options in Data Center

10 Gigabit Ethernet or 10GbE is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second. Nowadays, 10 Gigabit Ethernet is gaining broader deployments by the increasing bandwidth requirements and the growth of enterprise applications. In the world of 10 Gigabit Ethernet, selecting the appropriate 10-gigabit physical media is a challenge, because 10GbE is offered in two broad categories: optical and copper. This article will introduce both optical and copper cabling options for 10 Gigabit Ethernet.

Fiber Optical Cabling

Single-mode fiber (SMF), typically with an optical core of approximately 9 μm (microns), has lower modal dispersion than multimode fiber. It is able to support distances of at least 10 km, depending on transmission speed, transceivers and the buffer credits allocated in the switches. While multimode fiber (MMF), with an optical core of either 50 μm or 62.5 μm, can support distances up to 600 m, depending on transmission speed and transceivers.

When planning data center cabling requirements, be sure to consider that a service life of 15-20 years can be expected for fiber optic cabling. Thus the cable chosen should support legacy, current and emerging data rates.

10GBASE-SR — a port type for multimode fiber, 10GBASE-SR cable is the most common type for fiber optic 10GbE cable. It is able to support an SFP+ connector with an optical transceiver rated for 10GbE transmission speed. 10GBASE-SR cable is known as “short reach” fiber optic cable.

10GBASE-LR — a port type for single-mode fiber, 10GBASE-LR cable is the “long reach” fiber optic cable. It is able to support a link length of 10 km.

OM3 and OM4 are multimode cables that are “laser optimized” and support 10GbE applications. The transmission distance can be up to 300 m and 400 m respectively.

Copper Cabling

Common types of 10GbE copper cables are as follows:

• 10GBASE-CR — the most common type of copper 10GbE cable, 10GBASE-CR cable uses an attached SFP+ connector and it is also known as a SFP+ direct attach copper (DAC). This fits into the same form factor connector and housing as the fiber optic cables with SFP+ connectors. Many 10GbE switches accept cables with SFP+ connectors, which support both copper and fiber optic cables.
• Passive and Active DAC — passive copper connections are common with many interfaces. As the transfer rates increase, passive copper does not provide the distance needed and takes up too much physical space. So the industry is moving towards an active copper type of interface for higher speed connections. Active copper connections include components that boost the signal, reduce the noise and work with smaller gauge cables, improving signal distance, cable flexibility and airflow.
• 10GBASE-T — 10GBASE-T cables are Cat6a (category 6 augmented). Supporting the higher frequencies required for 10GbE transmission, category 6a is required to reach the distance of 100 m (330 feet). Cables must be certified to at least 500 MHz to ensure 10GBASE-T compliance. Cat 6 cables may work in 10GBASE-T deployments up to 55 m (180 feet) depending on the quality of installation. Some 10GbE switches support 10GBASE-T (RJ45) connectors. 10GBASE-T offers the most flexibility, the lowest cost media, and is backward-compatible with existing 1 GbE networks.

Fiberstore Solutions for 10 Gigabit Ethernet

As one of the most professional optical manufacturers in China, Fiberstore’s solutions for 10 Gigabit Ethernet include 10G SFP+ fiber, 10G SFP+ DAC. Besides, we also supply high quality 10G transceivers, like X2-10GB-SR, SFP-10G-ZR, SFP-10G-SR, XFP-10GZR-OC192LR, etc.

1000BASE-T Gigabit Ethernet Over Category 5 Copper Cabling

1000BASE-T Gigabit Ethernet over Category 5 copper cabling is an attractive option for network managers for several reasons. It addresses the exploding bandwidth requirements on current networks that are the result of implementation of new applications and the increasing deployment of switching at the edges of the network. Gigabit Ethernet leverages the organization’s existing investment in Ethernet and Fast Ethernet infrastructures, and it provides a simple, cost-effective performance boost while continuing to use the dominant horizontal/floor-cabling medium.

1000BASE-T Key Specifications

1000BASE-T is specified to run over four pairs of Category 5 balanced cabling. The 1000BASE-T standard leverages the existing cable infrastructure as it is specified to operate up to 100 meters on Category 5 cabling. The other key specifications of 1000BASE-T make it a cost-effective, non-disruptive, and high-performing technology. First, it supports the Ethernet MAC, and is thus backward compatible with a 10/100 Mbps Ethernet. Second, many 1000BASE-T products will support 100/1000 auto-negotiation, and therefore 1000BASE-T can be incrementally deployed in a Fast Ethernet network. Third, 1000BASE-T is a high-performing technology with less than one erroneous bit in 10 billion transmitted bits. This bit error rate of less than 10 – 10 is the same error rate as that of 100BASE-T.

Why 1000BASE-T Gigabit Ethernet Over Category 5 Copper Cabling?

• Exploding bandwidth requirements

New bandwidth-intensive applications are being deployed over Ethernet and Fast Ethernet networks. These applications include the following:
Internet and intranet applications that create any-to-any traffic patterns with servers distributed across the enterprise, and users accessing web sites inside and outside the corporate network; these applications tend to make traffic patterns and bandwidth requirements increasingly unpredictable. Data warehousing and backup applications that handle gigabytes or terabytes of data distributed among hundreds of servers and storage systems. Bandwidth-intensive, latency-sensitive groupware applications, such as desktop video conferencing or interactive whiteboarding.

• Significant investment in Ethernet/Fast Ethernet infrastructure

Ethernet is the dominant, ubiquitous LAN technology. According to industry analyst International Data Corporation (IDC) in Framingham, MA, more than 85 percent of all installed network connections were Ethernet at the end of 1997, representing more than 118 million interconnected PCs, workstations, and servers. The deployment of Ethernet/Fast Ethernet networks involves investment in network interface cards (NICs), hubs, and switches, as well as in-network management capabilities, staff training and skills, and cabling infrastructure.

• A simple, cost-effective performance boost on existing Category 5 cabling

1000BASE-T offers a simple, cost-effective migration of Ethernet/Fast Ethernet networks toward high-speed networking and also has the following benefits:
1000BASE-T scales Ethernet 10/100 Mbps performance to 1000 Mbps. 1000BASE-T is the most cost-effective, high-speed networking technology available now. 1000BASE-T leverages existing, proven Fast Ethernet and V.90/56K modem technologies and will experience the same cost curve as the Ethernet/Fast Ethernet technologies. 1000BASE-T is significantly more cost-efficient than 1000BASE-SX (Fiber Gigabit) among all LAN technologies. 1000BASE-T preserves Ethernet equipment and infrastructure investments, including the investment in the installed Category 5 cabling infrastructure. There is no need to undergo the timeconsuming and high-cost task of replacing cabling located in walls, ceilings, or raised floors.

Fiberstore 1000BASE-T Copper SFP Transceiver

Fiberstore’s 1000BASE-T copper small form pluggable (SFP) transceivers are based on the SFP Multi Source Agreement (MSA). They are compatible with the Gigabit Ethernet and 1000BASE-T standards as specified in IEEE Std 802.3. For instance, HP J8177C X121 compatible 1000BASE-T SFP copper RJ45 transceiver for 100m reach over Cat 5 UTP cable uses the SFP’s RX_LOS pin for link indication and supports 1000BASE-T operation on the host system. Another example is Brocade XBR-000190 compatible 1000BASE-TX SFP copper RJ45 transceiver which offers the same function with Brocade E1MG-TX/XBR-000190 and fully compatible with Brocade devices.

Cisco 10GBASE SFP+ Modules

The Cisco10GBASE SFP+ modules is one of the most popular kinds of transceivers which offers customers a wide variety of 10 Gigabit Ethernet connectivity options for data center, enterprise wiring closet, and service provider transport applications.

Main features of Cisco 10GBASE SFP+ modules include: it has the smallest 10G form factor ,hot-swappable input/output device that plugs into an Ethernet SFP+ port of a Cisco switch and optical inter operability with 10GBASE XENPAK, 10GBASE X2, and 10GBASE XFP interfaces on the same link. What;s more, it supports not only 10GBASE Ethernet and OTU2/OTU2e, “pay-as-you-populate” model, digital optical monitoring capability, but also the Cisco quality identification (ID) feature that enables a Cisco switch to identify whether the module is certified and tested by Cisco. The followings are some different kinds of Cisco 10GBASE SFP+ modules.

Cisco SFP-10G-SR

The Cisco SFP-10G-SR module supports link length of 26m on standard Fiber Distributed Data Interface (FDDI)-grade multimode fiber (MMF). Using 2000MHz*km MMF (OM3), up to 300m link lengths are possible. Using 4700MHz*km MMF (OM4), up to 400m link lengths are possible.

Cisco SFP 10G-SR-X

The Cisco SFP-10G-SR-X is a 10GBASE-SR module for extended operating temperature range. It supports a link length of 26m on standard Fiber Distributed Data Interface (FDDI)-grade multimode fiber (MMF). Using 2000MHz*km MMF (OM3), up to 300m link lengths are possible. Using 4700MHz*km MMF (OM4), up to 400m link lengths are possible.

Cisco SFP-10G-LRM

The Cisco 10GBASE-LRM module supports link lengths of 220m on standard Fiber Distributed Data Interface (FDDI) grade multimode fiber (MMF). To ensure that specifications are met over FDDI-grade, OM1 and OM2 fibers, the transmitter should be coupled through a mode conditioning patch cord. No mode conditioning patch cord is required for applications over OM3 or OM4. The Cisco 10GBASE-LRM module also supports link lengths of 300m on standard single-mode fiber (SMF, G.652).

Cisco FET-10G

The Cisco FET-10G fabric extender transceiver support link lengths up to 100m on laser-optimized OM3 or OM4 multimode fiber. It is supported on fabric links only from a Nexus 2000 to a Cisco parent switch. Note this product is not orderable individually.

Cisco SFP-10G-LR

The Cisco 10GBASE-LR module supports a link length of 10 kilometers on standard single-mode fiber (SMF, G.652).

Cisco SFP-10G-LR-X

The Cisco SFP-10G-LR-X is a multirate 10GBASE-LR, 10GBASE-LW and OTU2/OTU2e module for extended operating temperature range. It supports a link length of 10 kilometers on standard single-mode fiber (SMF, G.652).

Cisco SFP-10G-ER

The Cisco 10GBASE-ER module supports a link length of up to 40 kilometers on standard single-mode fiber (SMF, G.652).

Cisco SFP-10G-ZR

The Cisco SFP-10G-ZR is a multirate 10GBASE-ZR, 10GBASE-ZW and OTU2/OTU2e module. It supports link lengths of up to about 80 kilometers on standard single-mode fiber (SMF, G.652). This interface is not specified as part of the 10 Gigabit Ethernet standard and is instead built according to Cisco specifications.

Fiberstore is a leading supplier of SFP+ transceivers. We have a large selection of SFP+ transceivers in stock, such us SFP+ MM 300m, SFP+ 10km, SFP+ 40km, SFP+ 80km, CWDM SFP+, DWDM SFP+, BiDi SFP+, etc. All of our SFP+ transceivers are tested in-house prior to shipping to ensure that they will arrive in perfect physical and working condition. We offer our customers with high-performance and cost-effective products to fulfill their requirements, contributing this way to the customer's success and satisfaction.

How Much Do You Know About 40G QSFP+ Transceiver

QSFP+ transceiver is a hot-swappable, parallel fiber-optical module with four independent optical transmit and receive channels. These channels can terminate in another 40-Gigabit QSFP transceiver, or the channels can be broken out to four separate 10-Gigabit SFP+ transceivers. For instance, QSFP-40G-SR provides four channels of data in one pluggable interface and each channel is capable of transferring data at 10 Gbps and supports a total of 40 Gbps. It uses 38 position connector and Electro Magnetic Interference (EMI) plugs are offered for empty ports to interface networking hardware to a fiber optic cable. The QSFP product family includes cages in single and ganged configurations with various heat sink and lightpipe options.

Features and Benefits:

• Support for 40GBASE Ethernet
• Hot-swappable input/output device that plugs into a 40-Gigabit Ethernet QSFP+ Cisco switch port
• Flexibility of interface choice
• Interoperable with other IEEE-compliant 40GBASE interfaces available in various form factors
• Support for “pay-as-you-populate” model
• Support for the Cisco quality identification (ID) feature which enables a Cisco switch to identify whether the module is certified and tested by Cisco.

The QSFP+ transceiver link length for either 40 Gigabit Ethernet or high density 10 Gigabit Ethernet application is up to 100 m using OM3 fiber or 150 m using OM4 fiber. These modules are designed to operate over multimode fiber systems using a nominal wavelength of 850nm. The electrical interface uses a 38 contact edge type connector. The optical interface uses an 8 or 12 fiber MTP (MPO) connector.

The 40G QSFP+ transceiver module integrates 4 independent 10 gigabit per second data lanes in each direction to provide 40Gbps aggregate bandwidth. 40GBASE QSFP+ modules offer customers a wide variety of high-density 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications. The QSFP+ transceiver module connects the electrical circuitry of the system with either a copper or an optical external network. The transceiver is used primarily in short reach applications in switches, routers, and data center equipment where it provides higher density than SFP+ modules.

The QSFP specification supports Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. QSFP+ transceivers are designed to support Serial Attached SCSI, 40G Ethernet, 20G/40G Infiniband, and other communications standards. QSFP modules increase the port-density by nearly 3x when compared to SFP module. The QSFP transceiver include 40GBASE-SR4 and 40GBASE-LR4 for different applications.

40GBASE-SR4 QSFP+ transceiver supports link lengths of 100 meters and 150 meters, respectively, on laser-optimized OM3 and OM4 multimode fibers. While 40GBASE-LR4 QSFP+ transceiver supports link lengths of up to 10 kilometers over a standard pair of G.652 single-mode fiber with duplex LC connectors. For example, HP JH232A compatible 40GBASE-LR4 QSFP+ transceiver from Fiberstore supports link lengths of 10km on single mode fiber cable, at a wavelength of 1310nm. It primarily enables high-bandwidth 40G optical links with duplex LC connectors and can also be used in a 4x10G module for interoperability with 10GBASE-LR interfaces.  

Fiberstore provides a full range of 40G QSFP+ transceivers including single-mode and multi-mode with different channels and wavelengths. In addition to 40Gbps Ethernet interconnects, they can be used in switches, routers, as well as data aggregation and backplane applications. All these fiber optic transceivers are 100% compatible with major brands like Cisco, HP, Juniper, Nortel, Force10, D-link, 3Com. They are backed by a lifetime warranty, and you can buy with confidence. We also can customize optical transceivers to fit your specific requirements.

Fiber Optic Connectivity Options for 40G Infrastructure

Dramatic growth in data center throughput has led to the increasing usage and demand for higher speed and more bandwidths. The speed of data center now is increasing to 40 Gbps and eventually to 100 Gbps. Thus, new optical technologies and cabling infrastructure are required. This article will introduce some commonly used fiber optic cabling connectivity options for 40G infrastructure.

Pluggable Optical Modules: 40G QSFP+ Transceivers

As is known to all, fiber optic transceiver is a device that both transmits and receives data. It is the key component in fiber optic transmission. The basic interface of 40G pluggable optical modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor.

40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver supports with a link length up to 10 kilometers over 1310 nm single mode fiber with LC connector. It is most commonly deployed between data-center or IXP sites with single mode fiber.

40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support the transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP.

In addition, for single-mode fiber transmission, there are 40GBASE-LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km. For multimode fiber transmission, QSFP+ extended SR4 transceivers are developed which is designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.

Passive & Active Direct Attach Copper Cables

The QSFP+ passive or active direct attach copper cables are designed with twinax copper cable and terminated with QSFP+ connectors. The main difference between passive QSFP+ DAC and active QSFP+ DAC is that the passive one is without the active component. They provide short distance (same shelf) inexpensive connectivity at up to 40Gbps rates and operate 4 independent 10G channels using the QSFP connector footprint. Each of the four channels can operate at multi-rate speeds Gigabit to 10Gbps. For example, Juniper QFX-QSFP-DACBO-3M compatible QSFP+ to 4SFP+ copper direct attach cables are suitable for very short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP port and SFP+ port of Juniper switches within racks and across adjacent racks.

Active Optical Cable (AOC) Assemblies

Active Optical Cable (AOC) is used for short-range multi-lane data communication and interconnect applications. It uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. AOC brings a more flexible cabling than direct attach copper cables with the advantages of lighter weigth, longer transmission distance and higher performance for anti-EMI. Now, 40G AOC assemblies are popular with users.

Fiberstore offers a comprehensive solution for 40G fiber optic cabling connectivity. Apart from the above-mentioned cabling connectivity options, there are also some typical cabling components you will require when building 40G cabling, such as MTP trunk cables, MTP cassettes, LC to MTP jumpers and so on.