SFP Transceiver Communication Standards

SFP transceivers are compact, small form-factor pluggable transceivers. They are commonly deployed in data communication applications, as well as in telecommunications. The great thing about SFP transceivers in networking hardware is that they allow a single piece of equipment, such as a switch, to support different wiring and transmission formats. The problem comes when trying to figure out which of the many transceiver types out there you need. There are several different types of SFP transceivers capable of supporting a multitude of communication standards, such as: CWDM/DWDM, SONET, Fibre Channel, Fast Ethernet and Gigabit Ethernet.

CWDM/DWDM SFP Transceivers

WDM, or wavelength-division multiplexing, is a type of technology that allows a transceiver to have different wavelengths assigned to it.

Coarse wavelength-division multiplexing (CWDM) SFP transceivers are capable of transmitting data at eight different wavelengths ranging from 1470nm to 1610nm. CDWM SFP transceivers are color coded, to help identify which wavelength is mapped to the transceiver.

Dense wavelength-division multiplexing (DWDM) SFP transceivers are available in 32 different wavelengths, and offer high-capacity bandwidth for serial optical data communications. DWDM SFP transceivers are slightly more expensive than CWDM SFP transceivers, but the more densely spaced channels allow for a greater number of wavelengths to travel over a single fiber.

Both CWDM and DWDM SFP transceivers can be used to transmit data over Gigabit Ethernet, SONET and Fibre Channel.

SONET SFP Transceivers

Synchronous optical networking (SONET) technology enables the transmission of a large volume of data over long distances. SONET can be used to transmit multiple streams of data simultaneously over fiber optic mediums using laser beams and LEDs.

SFP transceivers are built to transmit data over SONET at varying rates (OC-3, OC-12 and OC-48) and with different reaches (short-reach, intermediate-reach, and long-reach). SONET SFP transceivers are able to transmit data over both singlemode and multimode fiber.

Fibre Channel SFP Transceivers

Fibre Channel is a protocol which is used primarily in "Storage Area Networks". It comes in different speeds like 1xFC, 2xFC, 4xFC, 8xFC and 16xFC. Fibre Channel was developed as a lossless protocol in a time when switches were less reliable than they are today. When using Ethernet as a protocol, frames were dropped, which created a problem for applications like data traffic. With the advent of greater technology, switches are now much more reliable; however, Fibre Channel still holds a small advantage over Ethernet when it comes to consistency and latency.

Fibre Channel SFP transceivers are modules commonly used in storage area networks (SAN) and are available in 1, 2, 4, 8, 10, 16 and 20Gbps data transmission rates. Fibre Channel SFP transceivers can be used in both singlemode and multimode fiber applications.

Fast Ethernet and Gigabit Ethernet

Fast Ethernet is slowly being replaced with Gigabit Ethernet. Fast Ethernet SFP transceivers were originally designed to transmit data at 10Mbps, and eventually reached transmission speeds of 100Mbps (100Base). 100Base rate Fast Ethernet transceivers are available in the following interface types: FX, SX, BX and LX10.

With the development of Gigabit Ethernet, SFP transceiver transmission rates increased to 1000Mbps (1000Base). 1000Base rate Gigabit Ethernet SFP transceivers are available in the following interface types: T (eg. MGBT1), SX, LX, LX10, BX10, and the non-standard EX and ZX.

FS.COM is sure to have the right SFP transceiver for your network! We carry a full line of both name-brand and affordable 100% compatible transceivers of every type your business could possibly need. Contact us today for a free consultation on which standards meet your business needs, or to discuss fiber connectivity network solutions that will best support your future business plans.

Guide to 10 Gigabit Ethernet Transceivers

10Gbps transceivers are also known as 10GbE or 10GBase transceivers. These transceivers transmit data at a base rate of 10 Gigabits per second typically using Ethernet protocol. With components fulfilling the same basic function available in five different form-factors, at first look the world of 10Gbps optical transceiver modules looks a bit cloudy. However, with the demand for more compact space, the 10G form factors have been developed along the way from the earliest XENPAK to modern SFP+. The following is a list of the MSAs published over the subsequent years:

XENPAK Transceivers

XENPAK, published in the year of 2001, was by far the largest in physical size. Driven by large systems vendors, this XENPAK standard was intended to support essentially any optical application a system vendor may want to deploy. At that time, 10Gbps optical interfaces supporting transmission distances of 80 km or more were of a size and heat dissipation that required a relatively large (by today’s standards) package size.

XPAK, X2 and XFP Transceivers

When recognizing the size of the XENPAK is too limited, vendors in this field began working on alternative standards. Over the following two years, three alternative MSAs, namely XPAK, X2 and XFP were published. When these standards were written they were intended to enable optical interfaces supporting up to about 10 km. While the XPAK standard was not a commercial success, the X2 and XFP form-factors both saw considerable deployment. As optical technology has advanced over the last ten years, X2 and XFP modules have been developed to support all of the high-power, long-distance applications once reserved to the larger XENPAK transceivers. The following is a comparison of the 10G transceiver sizes.

SFP+ Transceivers

Five years after the first 10Gbps optical transceiver standard was issued, a new MSA was published called the “SFP+”. This agreement has been the basis for the most commercially successful 10Gbps optical transceivers by a large margin. There are several reasons for the success of the SFP+ standard:

• Flexibility – The SFP+ standard builds on a previous one, the SFP MSA (primarily a 1Gbps standard). SFP+ modules are the same physical size as SFPs and the SFP+ standard allows for either type of module to operate in the new SFP+ slots.
• Small Size – As shown in the above figure, SFP+ modules are one tenth the size of the original XENPAK 10G modules and are the same size as the popular fiber SFP modules. This small size allows the design of systems with 10G ports of the same density as previous generations with 1G ports.
• Low Cost – Since SFP+ modules share many components (bezel, housing, latch/locking mechanism) on the previous SFP standard, the cost of the new 10G modules inherits the low cost of these components. SFP+ units are also lower power, contributing to cost savings.

How to Choose 10GBase Form-Factor?

Systems (such as routers, switches, media converters) designed within the last two or three years have implemented, with very few exceptions, the SFP+ standard for 10Gbps ports. If used – or new equipment of older design – is being considered, users must be careful to identify what type of port is built into their gear. So remember to refer to the equipment manufacturers specifications when choosing the suited 10GBase form-factor.

When considering new or used equipment for a new network build or expansion, attention should definitely be given to the type of 10Gbase ports in that equipment. One important reason is capital costs. Older gear offering XFP, X2 or XENPAK ports may be attractive due to what seems like very low prices. However, the cost of equivalent 10GBase optics in those older form factors is 2X to 3X the price of SFP+ based modules. Therefore, when the cost of the optics are included, total system costs may be higher. Other costs to consider are:

• Power – The older XFP, X2 and especially XENPAK gear, both the host system and the 10GBASE optical modules, consume more power than the SFP/SFP+ modules (like 10GBASE SR SFP module). Power costs include capital outlays for larger power/battery plant as well as operational cost of the electrical power itself.
• Rack Space – Depending on the location, space in equipment racks can be quite expensive. Equipment utilizing the older 10Gbase interfaces is almost always substantially less dense, consuming more rack space per 10G interface available.

Who Is the Winner Among 10GBase?

All in all, with the substantial advantages in cost, size and power, along with flexibility to support any type of optical interface while maintaining backward compatibility with previous SFPs, the SFP+ is obviously the winner in the 10GBase optical transceiver market. Although newer standards for higher speed, like 40Gbps and 100Gbps have already been launched, it can still be predicted that, SFP+ based optical transceivers are bound to continue to dominate the market for 10Gbps modules for the next 10 years or more.

3 Ways Third-Party Transceivers Benefit Your Data Center

Are you still spending hundreds of dollars on the expensive optical transceiver modules for your network system in the data center? In order to cut down the costs on the expensive transceiver modules, many companies are seeking for a compatible third-party transceiver to use. For example, if your network contains Juniper routers, firewalls, and switches, you might think that only Juniper SFP branded transceivers will ensure that all of your equipment is compatible and functions optimally. However, that seemingly reasonable assumption could cost your company thousands of dollars. Compared to the third-party optical transceiver produced by third-party companies, Juniper SFP transceiver comes with dramatically inflated price tags while a third-party compatible one is roughly 80 percent less expensive than Juniper branded SFP transceiver.

What Does "Third-Party" Mean?

In commerce, a "third-party" means a supplier (or service provider) who is not directly controlled by either the seller (first party) or the customer/buyer (second party) in a business transaction. For example, in the fiber optics industry, all fiber optic transceivers are defined by Multi-Source Agreement (MSA). MSAs strictly define the operating characteristics of fiber optic networking equipment, so that system vendors may implement ports in their devices that allow MSA compliant networking components produced by different manufacturers are interoperable. As long as a manufacturer complies to MSA guidelines, their transceiver modules will function and operate identically to any other manufacturer's MSA-compliant transceivers. For instance, HP BladeSystem 455883-B21 compatible 10GBASE-SR SFP+ transceiver from FS.COM will function identically to a HP 455883-B21 transceiver and will be 100% compatible with HP networking equipment.

Optical transceivers are some of the most all-around useful pieces of hardware for a network. As long as your equipment has SFP/SFP+ ports -which most do- transceivers allow you to change between a multitude of uplink types, to fit whatever wiring you have or will have in the future. They're simple, plug-and-play, and hot-swappable. Third-party optical transceivers can easily prevent thousands of dollars in new hardware costs. In spite of what's often implied by official documentation, a quality third-party optical transceiver is 100% compatible with name-brand equipment. There's simply no difference between good quality third-party transceivers and branded ones. So why choose to pay more?

Three Reasons Why Third-Party Optical Transceivers Just Make Sense

1. Low costs The lower costs of third-party optics really cannot be overstated. Depending on the model, name brands are anywhere from 50% to 1000% more expensive than third-party alternatives. For example, you can get the Cisco QSFP-40G-CSR4 compatible 40GBASE-CSR4 QSFP+ transceiver with only $110 at FS.COM which ensures the same performance with a Cisco branded QSFP-40G-CSR4 transceiver.

In many cases, a full loadout of third-party transceivers can shave so much money off of an upgrade budget to fund entirely new pieces of hardware. Or they can put a piece of equipment within range, which wouldn't have been if name-brand ports had to be purchased.

2. Full standards compliance Only a few factories in the world produce optics, and they make the transceivers for everyone. Those heavily-discounted third-party may be made in the same facilities as the official Cisco, HP, or Juniper units. And since transceivers are fully specified by internationally agreed-upon standards anyway, there's no risk of incompatibilities.

All it takes is code loaded on an EPROM -included in the transceiver- identifying it to your networking hardware and, basically, your equipment can't tell the difference.

3. Lifetime warranty Besides having much higher prices, the name-brand transceivers also tend to have fairly short warranty periods. It's generally anywhere from a couple years, down to only 90 days. While failure is fairly rare, it's unfortunate that they have such short warranty periods, especially compared to the hardware they're used in.

However, when you buy third-party optics from FS.COM, you will get a full lifetime warranty. That's how certain we are that they truly are of quality equal or better to the name-brand units. As long as your transceivers are in use, they're covered under warranty.

Conclusion

If you're still hesitant about trying a compatible SFP transceiver from a third party manufacturer, the best way to ensure that you're getting a reliable product at a good deal is to choose a vendor you trust, one with a proven track record of quality products and great customer service. Really, there's no compelling reason to over-pay for the name brand optics. Just like buying generic medications at the pharmacy, there is truly no difference aside from the name that's on the packaging.