Tag Archives: fiber optic transceiver

Can I Connect Optical Transceivers of Different Brand?

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Data centers generally accommodates hundreds or even thousands of network switches, it happens when you have to connect switches from different vendors (i.e. switch X from Cisco and switch Y from HP). As the switches only fit their own brand-based optical transceivers, the main issues thus falls into this: is it possible to contact two different vendor’s optical transceivers and form a viable link? The answer is yes – but you still have to take some critical aspects into account.

connect optical transceivers from different brand

A Basic Case Study: Standard of Optical Transceivers is the Key

Sometimes people have to mix switches and optical transceivers, mainly because the following reasons:

  • They already have brand X and they need more switches and they shop on price. Hence different brands
  • They need to replace switches but do not have money for all and they buy brand X and plan on going to brand X completely but it takes time to get there.

There exist quite a lot standards and protocols concerning optical transceivers. Although many installers are very familiar with linking different vendor’s switch, the others are still worried that the incompatibilities of two transceivers may impede the link performance. They may come across the questions like “Can I order a 1000BASE-LX transceiver from any source and it will be compatible with all others 1000BASE-LX?” or “Would a link with a Juniper 1000Base-LX and a Cisco 1000BASE-LX transceiver work?”

1000base-lx optical transceivers

Ideally it should work. 1000BASE-LX is a standard the same way 1000BASE-T is, except that it uses fiber as the transmission medium. You’ve already known that any copper interfaces with 1000BASE-T is interoperable since they are defined by the same 1000BASE-T standards. So you can expect the same with fiber 1000BASE-LX interfaces –  which are all defined by 1000BASE-LX. While this is true on the fiber side of the system, and should be true on the thing with the transceiver socket. In fact, you can rest assure as SFP is multi-vendor standard that specified by a multi-source agreement (MSA). And it is a popular industry format jointly developed by many network component vendors.

Further Consideration of Optical Transceivers: Protocol, Transmission Wavelength and Cable Type

Connecting SFP optical transceivers from two different vendors still have some other restriction, since SFP transceivers differs from one another in protocol, interface type and transmission distance.

Ethernet Protocol: You have to pay attention that you use optical transceivers of the same protocol at each end, for example: both sides with SX, LX or whatever is currently in use. Otherwise, you have to undertake the risk of link failure.

Cable Type: The optical transceivers on each end must use the same fiber type. An SFP made for multimode fiber isn’t going to work well, if it does at all, with single-mode fiber. Same applies with other multimode fiber types: although mixing various 50 um fibers (OM2 and OM4) may work OK depending on data rate and distance. As long as each end is the same fiber type, you can mix vendors and even connector types, such as SC on one end and LC on the other end.

Wavelength: It is vital the wavelength of the optical transceivers (850nm, 1310nm) matches on each end, as a 1310nm transceiver will NOT talk to a 850 nm transceiver. MMF has a lot of loss, and the wrong wavelength may cause loss and degradation on the longer runs. As for SMF, you need to be even more careful about wavelengths though, especially for long distance. So, if you are on the working range, all the transceiver will work normally.

wavelength for optical transceiver

Conclusion

It is hence safe to say that when connecting two optical transceivers from different vendors, you can expect you fiber patch cable to lead a consistent link as long as you use modules of the same Ethernet protocol, cable type and working wavelength. FS provides fully compatible optical transceivers with affordable price and decent performance. For more information, please visit www.fs.com.

Which Patch Cable Should I Choose for My Optical Transceiver?

As bandwidth demands increase, fiber optic patch cables and fiber optic transceivers become more and more important in fiber optic data transmission, especially in data transmission between the switches and equipment. But with so many different kinds of patch cables available in the market, which one is suitable for may optical transceiers? This article may on this issue to provide some solutions. Before starting this topic, it is necessary for us to review the basic knowledge of the fiber optic transceiver and fiber optic patch cable.

Fiber Optic Transceiver Overview
Fiber Optic Transceiver is a self-contained component that can both transmit and receive. Usually, it is inserted in devices such as switches, routers or network interface cards which provide one or more transceiver module slot. There are many optical transceivers types, such as SFP+ transceiver, X2 transceiver, XENPAK transceiver, XFP transceiver, SFP (Mini GBIC) transceiver, GBIC transceiver and so on.

Fiber Optic Transceiver

Fiber Optic Patch Cable Overview
Fiber optic patch cable, also known as fiber jumper or fiber optic patch cord. It is composed of a fiber optic cable terminated with different connectors on the ends. Fiber optic patch cables are used in two major application areas: computer work station to outlet and patch panels or optical cross connect distribution center. According to fiber cable mode, cable structure or connector types etc., fiber patch cable can be divided into different types.

Fiber Optic Patch Cable

1.Single-mode and Multimode Patch Cable
According cable mode, patch cables can be divided into single-mode and multimode fiber patch cable. The word mode means the transmitting mode of the fiber optic light in the fiber optic cable core. Single-mode patch cables are with 9/125 fiber glass and are yellow jacket color, while multimode patch cables are with OM1 62.5/125 or OM2 50/125 fiber glass and are orange color. In addition, there is 10G OM3 and OM4 multimode patch cables which cable jacket are usually aqua.

2.Simplex and Duplex Patch Cable
Simplex fiber patch cable is consist of single fiber core, while duplex fiber patch cable is consist of two fiber cores and can be either singlemode or multimode. Additionally, there is also ribbon fan-out cable assembly (ie. one end is ribbon fiber with multi fibers and one ribbon fiber connector such as MTP connector (12 fibers), the other end is multi simplex fiber cables with connectors such as ST, SC, LC, etc.).

3.LC, SC, ST, FC, MT-RJ, E2000, MU and MPO/MTP Patch Cable
Fiber optic patch cable can be also classified by the types of fiber optic connector. For example, LC fiber optic patch cable is named as it is with LC connector. Similarly, there are SC, ST, FC, MT-RJ, E2000, MU and MPO/MTP fiber optic patch cables. What’s more, there are PC, UPC, APC type fiber patch cords, which are differentiated from the polish of fiber connectors.

Which Patch Cable Should I Choose for My Fiber Optic Transceivers?
Now, I will take the Cisco fiber optic transceiver as an example to discuss this topic. For example, we need to choose a right patch cable to connect Cisco fiber optic transceiver SFP-10G-SR and X2-10GB-SR. Which patch cable to use? According to “Cisco 10-Gigabit Ethernet Transceiver Modules Compatibility Matrix”, we may know that SFP-10G-SR is the 10GBASE-SR SFP+ transceiver module for MMF, 850-nm wavelength, LC duplex connector. And X2-10GB-SR is the 10GBASE-SR X2 transceiver module for MMF, 850-nm wavelength, SC duplex connector. Obviously, this two knids of optica trancseivers are both for MMF, so we should choose a multimode patch cable. Besides, we know X2-10GB-SR is designed for SC duplex connector and the SFP-10G-SR is designed for duplex LC connector, so we should use a patch cable with SC-LC duplex connector.

Which Patch Cable Should I Choose for My Fiber Optic Transceivers

The Most Common Used Pacth Cable Selection
In the way mentioned above, you could choose right fiber patch cable for your other transceiver modules. Keep in mind that if your transceiver modules are not Cisco’s, you need to ask your brand supplier to get the corresponding compatibility matrix. In fact, in terms of a same kind of optical transceiver, different supplier may provide the transceiver with different specifications. Here I may list the most common used patch cables selection. Hope to give you smoe reference.

Fiber optic patch cable Applicable fiber optic transceiver connection
LC-LC Simplex 9/125 Single-mode Fiber Patch Cable 1.25Gbps 1310nmTX/1490nmRX BiDi SFP

10GBASE 1270nmTX/1330nmRX BiDi SFP+

LC-LC Duplex 9/125 Single-mode Fiber Patch Cable 1000Base-LX/LH 1310nm 10km LC SMF SFP
LC-SC Duplex 9/125 Single-mode Fiber Patch Cable Cisco X2-10GB-LR , Cisco XENPAK-10GB-LR and Cisco SFP-10G-LR
SC-LC Duplex 10G OM4 50/125 Multimode Fiber Patch Cable Cisco XENPAK-10GB-SR , Cisco X2-10GB-SR and Cisco SFP-10G-SR
LC-LC Duplex OM1 62.5/125 Multimode Fiber Patch Cable 100Base-FX 2km 1310nm MMF LC SFP
LC-LC Duplex OM2 50/125 Multimode Fiber Patch Cable 1000Base-SX 850nm 550m LC MMF SFP
LC-LC Duplex 10G OM3 50/125 Multimode Fiber Patch Cable 10GBASE-SR 850nm 300m Multi-Mode SFP+
LC-LC Duplex 10G OM4 50/125 Multimode Fiber Patch Cable Cisco SFP-10G-SR Compatible 10GBASE-SR SFP+

Related Article: Differences Between SFP, BiDi SFP and Compact SFP

How to Test a Fiber Optic Transceiver?

Transceiver testWhen optical transceivers was first deployed, verifying the performance of it was straightforward. The entire network was installed and owned by a single company, and if the system worked, extensive testing of the subcomponents was unnecessary. Today, however, most optical networks use components that may come from a variety of suppliers. Therefore, to test the compatibility and interoperability of each fiber optic transceiver becomes particularly important. How to test a fiber optic transceiver? This article may give you the answer.

As we all know, basically, a fiber optical transceiver consists of a transmitter and a receiver. When a transmitter through a fiber to connect with a receiver but the system doesn’t achieve your desired bit-error-ratio (BER), is the transmitter at fault? Or, is it the receiver? Perhaps both are faulty. A low-quality transmitter can compensate for by a low-quality receiver (and vice versa). Thus, specifications should guarantee that any receiver will interoperate with a worst-case transmitter, and any transmitter will provide a signal with sufficient quality such that it will interoperate with a worst-case receiver.

Precisely defining worst case is often a complicated task. If a receiver needs a minimum level of power to achieve the system BER target, then that level will dictate the minimum allowed output power of the transmitter. If the receiver can only tolerate a certain level of jitter, this will be used to define the maximum acceptable jitter from the transmitter. In general, there are four basic steps in testing an optical transceiver, as shown in the following picture, which mainly includes the transmitter testing and receiver testing.

Fiber Optic Transceiver test

Transmitter Testing
Transmitter parameters may include wavelength and shape of the output waveform while the receiver may specify tolerance to jitter and bandwidth. There are two steps to test a transmitter:
Transmitter Testing1. The input signal used to test the transmitter must be good enough. Measurements of jitter and an eye mask test must be performed to confirm the quality using electrical measurements. An eye mask test is the common method to view the transmitter waveform and provides a wealth of information about overall transmitter performance.

Transmitter Testing2. The optical output of the transmitter must be tested using several optical quality metrics such as a mask test, OMA (optical modulation amplitude), and Extinction Ratio.

Receiver Testing
To test a receiver, there are also two steps:
Receiver Testing3. Unlike testing the transmitter, where one must ensure that the input signal is of good enough quality, testing the receiver involves sending in a signal that is of poor enough quality. To do this, a stressed eye representing the worst case signal shall be created. This is an optical signal, and must be calibrated using jitter and optical power measurements.

4. Finally, testing the electrical output of the receiver must be performed. Three basic categories of tests must be performed:

  • A mask test, which ensures a large enough eye opening. The mask test is usually accompanied by a BER (bit error ratio) depth.Receiver Testing
  • Jitter budget test, which tests for the amount of certain types of jitter.
  • Jitter tracking and tolerance, which tests the ability of the internal clock recovery circuit to track jitter within its loop bandwidth.

In summary, testing a fiber optic transceiver is a complicated job, but it is an indispensable step to ensure its performance. Basic eye-mask test is an effective way to test a transmitter and is still widely used today. To test a receiver seems more complex and requires more testing methods. Fiberstore provides all kinds of transceivers, which can be compatible with many brands, such as Cisco, HP, IBM, Arista, Brocade, DELL, Juniper etc. In Fiberstore, each fiber optic transceiver has been tested to ensure our customers to receive the optics with superior quality. For more information about the transceivers or compatible performance test, please visit www.fs.com or contact us over sales@fs.com.

Source: http://www.fs.com/blog/how-to-test-a-fiber-optic-transceiver.html

The Chanllenges of Technology And Cost 100G Faced

More and more high bandwidth services such as high definition(HD) video, online games and video conference challenging the traditional network, 100G as a ease network bandwidth technology, becomes the new hope of the operator.

100G industry chain has matured, with all components and subsystems have commercial capacity of multiple manufacturers, the market also needs the support of 100G system, the backbone network will be fully transferred to the 100G-leading era. From the early 2013, the focus point of 100G is from the laboratory into 100G network deployment and the commercial 100G has started.

Four Technical Challenges Of 100G

Although the 100G has been carried out, but the 100G transmission technology meets four technical challenges.

First, high power consumption. The achievement mechanism of 100G technology is complex, the optical receiver requires the use of coherent reception and processing of the DSP, the key chip has no ASIC, resulting in high power consumption of the whole 100G system. When large-scale commercial 100G technology, the average power consumption of each wavelength is still a problem waiting to be solved. Currently the power consumption of per wavelength is above 200W, the average power consumption of per frame is 7000W, so there will need three frames. Obviously, the 28nm process can help to reduce energy consumption, but there is no 100G solution of 28-nanometer. In addition, although the light energy consumption is not large, but due to the use of next-generation optical transceiver will increase greatly, reducing the power consumption is very necessary.

The second is integrated, especially in the field of optical circuit and photoelectric integration. How to add mass active and passive optical devices such as laser, optical amplifier, wavelength division multiplexing(WDM) and transmitter/receiver to the network to achieve highly integrated? Using semiconductor technology to the integration of CWDM and laser?

The third is test. The challenges of 100G testing include the quality evaluation of the deployed 100G system signal and the system maintenance after deployed. 100G using polarization multiplexing, and the signal spectrum is wide, the common OSDR and test instruments can not real-time test it, only by shutting off the laser method. How to achieve real-time test is industry’s future research topic, many of today’s online testing system are worth studying.

The Fourth is few prospective studies. How to make the current transmission system gradually shift to user-oriented management from the traditional network management? Quickly and efficiently allocate the physical resources?

The key is the problem of cost

The key reason why 100G failed to be applied large-scale currently is the opportunity cost is relatively too high. In the era of 100G, the cost of optical module is very high. The mainstream CFP module, the actual sales price is more than $10,000. From the point of optical module cost, 100G module is several times higher than 10G optical module. It also requires manufacturers continue to make efforts in chip integration, integrated optical module miniaturization and system design, to achieve the overall cost of products are reduced.

Especially the regard of optical module technology, the cost of this part is the key of the whole 100G system cost, the optical module itself has to face the challenges of control power consumption and improve board integration.