Category Archives: Fiber Optical Transceivers

SFP-10G-SR-S vs SFP-10G-SR, Why Choose One Over the Other?

SFP-10G-SR is a popular 10G SFP+ optical transceiver in terms of quantity used. It is considered as the mainstream form factor of the 2017 market due to its matured technology and reduced price, even although 40G/100G optical modules are on the very top trend for enterprise and data center for the interconnection. But two years ago, Cisco introduced S-class optics such as SFP-10G-SR-S for enterprise and data center applications. For some web searchers, he will be recommended with SFP-10G-SR-S rather than SFP-10G-SR. But they almost share the same characteristics, so SFP-10G-SR-S vs SFP-10G-SR, why choose one over the other? Hope this post may give some clue.

SFP-10G-SR-S vs SFP-10G-SR: Similarity

Seemingly and technically, they don’t have much difference. SFP-10G-SR-S shares the same product specification with SFP-10G-SR. SFP-10G-SR is compliant with 10GBASE-SR standard. The Cisco 10GBASE-SR module supports a link length of 26m on standard Fiber Distributed Data Interface (FDDI)-grade multimode fiber, up to 300m link lengths over OM3 and 400m link lengths over OM4 cables.

SFP-10G-SR-S vs SFP-10G-SR: Similarity

Cisco SFP-10G-SR transceiver is hot-swappable input/output device which allows a 10 Gigabit Ethernet port to link with a fiber optic network. Because it is hot-swappable and MSA compliant, the Cisco SFP-10G-SR transceiver can be plugged directly into any Cisco SFP+ based transceiver port, without the need to power down the host network system. This capability makes moves, add-ons and exchanges quick and painless.

SFP-10G-SR-S vs SFP-10G-SR: Difference

According to Cisco, S-class optics are intended for enterprise and data center 10G and 40G applications This new set of optics does not display several unnecessary features for these applications, bringing about a more attractive price. That explains why SFP-10G-SR-S price is lower than SFP-10G-SR price.

Except the price, there are some other differences. SFP-10G-SR-S optics aren’t TAA certified. However, the non-S-class optics such as SFP-10G-SR are all compliant to TAA. SFP-10G-SR-S optics only have COM (Commercial temperature range: 0~70℃). However, the temperature range of SFP-10G-SR can be EXT (Extended temperature range: -5~85℃), IND (Industrial temperature range: -40~85℃) and Storage temperature range (-40~85℃). In terms of protocols, SFP-10G-SR-S optics use Ethernet only, they cannot use OTN (Optical Transport Network) or WAN-PHY (Wide Area Network Physics). Furthermore, SFP-10G-SR-S optics just have 10G and 40G applications so far which is specified for 10G and 40G enterprise and data center. Thus, if you don’t need any special features like extra tolerance for temperature, S-Class optics can save you a considerable amount of money.

SFP-10G-SR Price Comparison

Since equipment SFP-10G-SR vendors all rely on MSAs when designing their transceivers, every supplier can produce the transceiver modules with the same functions but with different prices. Unless you have a 100% requirement to buy Cisco, there are a lot of 3rd party compatible vendors out there that you can save a lot of money by using. Here is a price list from different vendors for you to choose from.

Vendor Model Brand Price
CDW SFP-10G-SR Cisco $693.99
Router-Switch SFP-10G-SR Cisco $262.00
Monoprice SFP-10G-SR Ironlink $136.75
10Gtek SFP-10G-SR 10Gtek $41.05
FS.COM SFP-10G-SR FS.COM $16.00

SFP-10G-SR-S vs SFP-10G-SR, Which Will You Choose?

Although SFP-10G-SR-S vs SFP-10G-SR, they share identical specification, there still are some minor difference. In most cases, SFP-10G-SR-S optics are recommended for 10G and 40G applications due to its low cost. both SFP-10G-SR price and SFP-10G-SR-S price is relatively lower according to the above chart, and they also enjoy good quality. If you need any third-party optical modules or fiber optic cables, give FS.COM a shot.

Related Articles:

Knowledge of SFP-10G-SR Price and Compatibility

Introduction To 10GBASE-T SFP+ Transceiver From Different Manufacturers

10GBASE-T is an Ethernet specification using a copper twisted pair connection (Cat6a or Cat7) with an effective bandwidth of 10 Gbit/s and a maximum transmission distance of up to 100 meters. Compared with other 10G optical module, the 10GBASE-T SFP+ RJ45 copper transceiver has stable performance, you can take full advantage of the existing copper cabling. It’s now becoming a hot option for equipment designers and data center professionals in building their network solution. Thus, there are many manufactures providing 10GBASE-T SFP+ transceivers, like HPE 10GBASE-T SFP+ transceiver, Cisco 10GBASE-T SFP and also FS.COM 10GBASE-T SFP+ copper transceiver. This post will introduce the characteristics of 10GBASE-T SFP+ transceiver of different manufactures respectively, and then you can choose what you want according to your budget.

HPE 10GBASE-T SFP+ Transceiver

According to HPE product specification, the HPE 10GBASE-T SFP+ Transceiver can convert a 10 Gb SFP+ port on an Hewlett Packard Enterprise switch to a 10GBase-T connection. It is specifically designed for high speed communication links that require 10 Gigabit Ethernet over Cat 6a/7 cable. This SFP+ transceiver offers 10 Gb/s communication over RJ45 copper cables. Its specification is shown as follows:

Ports 10GbE SFP+ port; Duplex: full only Interface RJ45
Weight 0.04 lb, fully loaded Operating temperature

 

32℉- 158℉(0℃-70℃)
Operating relative humidity 5%-95%, noncondensing Altitude

 

Up to 10,000 ft
Power consumption maximum 2.5W Cable type Cat6a/7 cable
Maximum distance 30 m Fiber type

 

Copper

Cisco 10GBASE-T SFP+ Transceiver: SFP-10G-T-S

The Cisco 10GBASE-T SFP is hot-swappable input/output device which allows a 10 Gigabit Ethernet port to link with a fiber optic network. Because it is hot-swappable and MSA compliant, the Cisco 10GBASE-T SFP+ copper transceiver can be plugged directly into any Cisco SFP+ based transceiver port, without the need to power down the host network system. This capability makes moves, add-ons and exchanges quick and painless. The specification of 10GBASE-T Cisco copper transceiver is as follows:

Cisco genuine SFP-10G-T-S Form type SFP+
Max data rate 10.3125Gbps Max transmission distance

 

30 m
Interface RJ45 Cable type

 

Cat6a/cat7
DOM support No Operating temperature 32℉- 158℉(0℃-70℃)

FS.COM 10GBASE-T SFP+ Transceiver: SFP-10G-T

The 10GBASE-T copper SFP+ transceiver FS.COM offered can convert a 10GbE SFP+ port on a switch or NIC (network interface card) to a 10GBASE-T RJ45 connection, allowing 10G bandwidth over existing copper infrastructure instead of changing to new fiber network equipment. It supports links up to 30 m over Cat6a/7 cable. Compared with an embedded 10GBASE-T RJ45 port for link distances up to 30 m, this module has been optimized to save more than 0.5 W per port. Its details are shown as follows:

Part number SFP-10G-T Form type SFP+
Data rate 10Gbps, 5Gbps, 2.5Gbps, 1000Mbps Cable distance

 

Up to 100m*
Power consumption 2.5W Interface

 

RJ45
DOM support No Operating temperature 32℉- 158℉(0℃-70℃)
*Note: 30 meters via 10Gbps, 50 meters via 5Gbps and 2.5Gbps, 100 meters via 1000Mbps.

Cisco sfp-10g-t-s compatible 10gbase-t sfp+

Conclusion

According to aforementioned, no matter HPE 10GBASE-T SFP+ transceiver, Cisco 10GBASE-T SFP+ or FS.COM 10GBASE-T SFP+ copper transceiver all share similar characteristics, like maximum power consumption, form type, interface, operating temperature and so on. But there is one thing that must differ, that is price. HPE 10GBASE-T SFP+ transceiver is charged $685.99 on official online store, Cisco Compatible 10 Gigabit RJ45 Copper SFP+ Prolabs transceiver module is about $395 on ebay and 10Gtek charges that for $339.99, while FS.COM 10GBASE-T SFP+ copper transceiver only costs $280, which is much lower.

FS.COM now provides compatible 10GBASE-T copper SFP+ transceivers as a new optional solution for your network architecture. Customized service is available for a specific brand compatible copper SFP+ module to your requirements. The following table gives some copper SFP+ product numbers and descriptions for your reference:

Product ID Description
66612 Generic Compatible 10GBASE-T SFP+ Copper RJ-45 30m Transceiver
66613 Cisco SFP-10G-T-S Compatible 10GBASE-T SFP+ Copper RJ-45 30m Transceiver
66614 Arista Networks SFP-10GE-T Compatible 10GBASE-T SFP+ Copper RJ-45 30m Transceiver
66615 H3C SFP-XG-T Compatible 10GBASE-T SFP+ Copper RJ-45 30m Transceiver
66616 Dell GP-10GSFP-T Compatible 10GBASE-T SFP+ Copper RJ-45 30m Transceiver
66617 Customized Compatibility 10GBASE-T SFP+ Copper RJ-45 30m Transceiver

Related Articles:

10GBASE-T SFP+ Copper Transceiver: A New Option For 10GbE Network

Choose 10GBASE-T Copper Over SFP+ for 10G Ethernet

10GBASE-T vs SFP+, Which Is the Best 10G Network Solution?

Understanding of 10GBASE-T SFP+ Copper Transceiver Modules

10G Copper SFP+ Transceiver: A New Option For 10GbE Network

10GBASE-T SFP+ transceiver is specifically designed for high speed communication links that require 10 Gigabit Ethernet over copper cable (Cat 6a/7 cable). 10GBASE-T SFP+ copper transceiver is the first SFP+ transceiver that offers 10 Gb/s communication over this type of media. Compared with other 10GbE optical modules, the 10G copper SFP+  transceiver has stable performance, you can take full advantage of the existing copper cabling. The following post will briefly introduce some related information about 10GBASE-T copper SFP+ transceiver.

Basic Introduction to 10GBASE-T Copper SFP+ Transceiver

10G copper SFP+ transceiver has high performance, good reliability and is a cost-effective I/O solution for 10G Ethernet and 10G Fibre Channel applications. SFP+ 10GBASE-T copper transceiver is mainly used in Cat 6a or Cat 7 copper cabling system for 10G transmission with a maximum distance up to 100m. In addition, compared with SFP+ DAC cable, 10GBASE-T copper SFP+ transceiver can save at least 0.5W power consumption, and its port can both support STP (shielded twisted pair) and UTP (unshielded twisted pair). Therefore 10GBASE-T SFP+ transceiver is becoming more and more popular in network switches and servers because of its lower power consumption and pay-as-you-grow flexibility.

10G Copper SFP+ Transceiver Vs. SFP+ Optical Transceiver Vs. SFP+ DAC

SFP+ DAC, SFP+ optical transceiver and 10GBASE-T SFP+ copper transceiver are three common components used in 10G connections. The following chart reveals the differences between them.

10G Copper SFP+ Transceiver Vs. SFP+ Optical Transceiver Vs. SFP+ DAC

Form the figure, we can see that each option has its advantages, but 10GBASE-T’s compatibility with existing structured cabling devices and existing low-speed devices makes it uniquely suited for widespread deployment. These features, combined with superior cost and achievable features, make the simplest path of 10GBase migrate from Gigabit Ethernet to 10G Ethernet. What’s more, the 10GBASE-T SFP+ transceiver module has been optimized to save at least 0.5W per port compared to an embedded 10GBASE-T RJ45 port for link distances up to 30m. Thus, the power savings and corresponding operating cost reduction can be substantial.

Features & Advantages of 10GBASE-T Copper SFP+ Transceiver

  • Cost effective at up to 30m distance on UTP cables
  • Extension of the life of any switch hardware, without having to change existing infrastructure
  • Architecture Flexibility: Supports Top of Rack, Middle of Row or End of Row architectures
  • Auto-negotiable backward-compatibility with previous-generation BASE-T networks for a seamless migration to 10GbE
  • Field twisted pair cabling with familiar RJ-45 connector
  • Support for multi-gigabit data rates up to 10 Gbps

10g copper sfp+ rj45 port

Conclusion

As 10GBASE-T network equipment becomes increasingly available, data center decision makers will want to take advantage of the cost savings, convenience, and flexibility provided by deploying 10 Gb/s technology over balanced twisted-pair copper cabling. Nowadays SFP+ 10GBASE-T transceiver, owing to the compatible issue with switches, is not offered by many vendors. However, from a network equipment designer’s perspective, 10G copper SFP+ modules will become popular in the near future. FS.COM has released 10GBASE-T SFP+ copper modules that are tested compatible with major brands like Cisco, Juniper, Dell, Brocade, Arista.

Related Articles:

Introduction To 10GBASE-T SFP+ Transceiver From Different Manufacturers

Understanding of 10GBASE-T SFP+ Copper Transceiver Modules

Choose 10GBASE-T Copper Over SFP+ for 10G Ethernet

How to Solve the Problems When Using SFP Optical Transceiver

The small form-factor pluggable (SFP) optical transceiver is one of the protagonists of modern networking, which is a hot-swappable, compact media connector used for telecommunication and data communications. It is designed to provide instant fiber connectivity for your networking devices, such as routers and switches. It is a cost-effective way to connect a single network device to a wide variety of fiber cable for different distances and fiber types, including Ethernet, SONET, single-mode fiber, and multi-mode fiber. Therefore, most people are using SFP optical transceivers for their 1G transmission, especially Cisco SFP optical transceiver. At the same time, there are many problems when using these SFP optical transceivers. This article may summary the problems that may occur and provide the guided solutions for you, as well as give you some notes for maintaining the quality of SFP optical transceivers.

SFP Transceiver

Problems & Solutions

Some problems may appear when we are using SFP optical transceiver. Now let’s talk about why these problems happen and how to solve these problems. The problems are classified as transmitting failure and receiving failure. The problems and solutions are as follows:

Optical Interface Is Polluted and Damaged

Owing to the pollution and damage of the optical interface, its optical link loss become higher, resulting in the optical link fails.

Solutions
  • Testing the environment of the exposed optical interface, some dust and pollution may enter into the structure.
  • Testing the link ending of optical fibers, because the optical interface may experience second pollution.
  • Testing the interface of the optical connector with pigtail, it may have some improper uses.
  • Testing the quality of fiber optic connectors, you could use the inferior optical fiber connectors.
Damage of ESD(Electro Static Discharge)

Static electricity will absorb dust, which may change impedance line and affect the life and function of the product. The ESD will damage components, which may work in short-term, but their life is still affected.

Solutions
  • Avoiding the dry environment, for which easily produce the ESD.
  • Avoiding the abnormal operation. For example, operating the non-hot-swappable optical modules with electricity; directly touching the pin of transceiver module by hand without ESD protection; there is not anti-static packaging during the transport and storage process.
  • Avoiding non ground-connection or bad ground connection.
  • Improving the ESD immunity of electronic components, because the ESD is inevitable.
Incompatibility

While SFP transceivers are fully-compliant with IEEE 802.3 and the SFP multi-source agreement (MSA), they may not be compatible with some network switch equipment. Because some switch manufacturers program their equipment to accept only their own brand of SFPs.

Solutions

Each SFP module holds its own memory in Electrically Erasable Programmable Read – Only Memory (EEPROM). This memory is coded with unique identifiers. The firmware of the host device will check the memory for the correct information to confirm compatibility. A SFP transceiver will work in any host device as long as it has the correct coding. Advance transceivers are coded specifically to suit each host device to avoid this problem.

Notes for Maintaining the Quality of SFP Optical Transceiver

Quality is also very important for SFP optical transceiver, for which is the top priority of customers. Here are some notes:

  • Finding the failure product in advance before shipment
  • Prohibiting the faulty module to leave the factory
  • Decreasing reject rate
  • Guaranteeing the working stability of the products after leaving the factory
Summary

SFP optical transceiver provides a cost-effective and flexible solution for network designs. I hope this article can help you solve the problems when you are using the products and learn how to avoid these problems.

QSFP+ to SFP+ Adapter (QSA Adapter) Vs. QSFP+ to SFP+ Breakout Cable

People frequently ask about feasible solutions between 10G and 40G servers. QSFP+ breakout cables like QSFP+ to 4 SFP+ cables and MTP to 4 LC harness cables are the commonly used equipment to connect between QSFP+ ports and SFP+ ports. But recently, Cisco launched a new type of product—QSFP+ to SFP+ Adapter (QSA Adapter) module that could provide a smooth migration to 40 Gigabit Ethernet. Is it a better solution for the 10G to 40G migration? Should I use the QSA adapter or 40G QSFP+ breakout cable? This article will answer the above questions and provide some suggestions to you.

QSA Adapter—Is It a Better Solution for 40G Migration?

The QSFP+ to SFP+ Adapter (QSA Adapter), specified by Cisco, is the module built in QSFP+ form factor with a receptacle for SFP+ cable connector at the back (seen in the below image). When connecting the QSFP port to an SFP+ port, QSA adapter usually acts as an interface for SFP+/SFP cables. That means you can effectively plug in an SFP+/SFP optics operating at a 10 Gbps port on this module, then inserting the module into a QSFP port cage to realize the 40G Ethernet transition. QSA adapter ensures the smooth connectivity between 40 Gigabit Ethernet adapter and 10 Gigabit hardware using SFP+ based cabling. Therefore, once the QSA adapter came out in 2016, it was soon considered as the effective solutions for converting 40G ports to the 10G ports.

Cisco QSA adapter module

40G QSFP+ Breakout Cables Overview

People usually use either the QSFP+ to 4 SFP+ breakout cables or MTP to LC harness cables to convert the downlink 40G port of ToR (Top of Rack) access layer switch into 4x10G fan out mode, then connect to the 10G cabinet server port. QSFP+ to SFP+ breakout cable including the direct attach copper cable (DAC) and active optical cable (AOC) consists of a QSFP+ connector on one end and four SFP+ connectors on the other end. The cables use high-performance integrated duplex serial data links for bidirectional communication on four links simultaneously.

QSFP+ to SFP+ breakout cable

While the MTP to LC harness cable have one one MTP cables on the one end and four LC connectors on the other end. This type of cable is recommended to be used in the same rack within the short distance. The picture above shows the direct connectivity between the QSFP+ transceivers and SFP+ transceivers by using the MTP to LC harness cable.

QSA Adapter or QSFP+ Breakout Cable?

In this part, I will make a comparison between QSFP+ to SFP+ adapter modules (QSA Adapter) and QSFP+ breakout cables from the aspects of cost, performance and compatibility.

Cost—QSFP+ Breakout Cables Wins

QSA adapter module is not certificated by Multi-source Agreement (MSA), but a sole source paradigm defined by few vendors. The only vendor owns its patent, so the QSA adapters on the market are quite expensive. Nevertheless, QSFP+ breakout cables covered in the MSA standard, support both copper and optical connectivity, which are much cheaper than QSA adapters. Cost comparison between QSA adapter and QSFP+ breakout cable (DAC, 1m) is listed in the below table.

cost comparison between QSA adapter and QSFP+ breakout cable

Performance

With QSA adapter, users have the flexibility to use any SFP+/SFP optics to connect to the 40Gbps data rate with a single 10G connection. However, QSA adapter only exists in 10G-40G speed, which also explains the reasons of its unpopularity of the market. QSFP+ to 4 SFP+ breakout cables split the 40G channel into 4x10G channel which provide four times more data transfers than QSA adapter does.

Compatible Switch and SFP/SFP+ Modules

QSA adapters, according to Cisco, are available in 40 Gigabit Ethernet compatibility matrix. Cisco SFP/SFP+ transceivers that can be plugged into the QSA adapters are concluded as Cisco 10GBASE-SR, LR, ER, ZR, DWDM SFP+, FET-10G and 10G SFP+ cable as well as SFP (1000BASE-T, SX, LX, EX, ZX). As for the QSFP+ to SFP+ breakout cables, different vendors have different compatible issues. Keep in mind that you should find the reliable fiber optic transceiver manufacturers.

Reminder:

  • Before using the QSA adapters or the QSFP+ breakout cables to connect a 40 Gigabit Ethernet port to a 10 Gigabit SFP+ port, you must enable the fan-out mode of your devices.
  • Not all the 40G cards and switches can be split into 4x 10Gb mode, for example, the Mellanox QSFP cards do not support the QSFP to SFP+ breakout, but their switches can.
  • With the QSA adapters, you can directly use the SFP+ modules in a QSFP+ port, but you cannot use the QSFP+ optical cables in a QSA setup.
  • Telecom industry has been modified rapidly. Hence, it is more cost-effective to make additional investment in high-speed switches instead of breakout cables and expensive QSA adapters.
Conclusion

Both the QSFP+ breakout cables and QSA adapters provide a smooth migration to the 40 Gigabit Ethernet. With these optics, you can reuse the existing 10G SFP+ cables, optical transceivers and switches when upgrading to 40G Ethernet. QSFP+ breakout cables is regarded as the cost-effective and reliable solutions for the most situations, but QSA adapter is preferable for the application with a single 10G connection.

Can I Use the QSFP+ Optics on QSFP28 Port?

100G Ethernet will have a larger share of network equipment market in 2017, according to Infonetics Research. But we can’t neglect the fact that 100G technology and relevant optics are still under development. Users who plan to layout 100G network for long-hual infrastructures usually met some problems. For example, currently, the qsfp28 optics on the market can only support up to 10 km (QSFP28 100GBASE-LR4) with WDM technology, which means you have to buy the extra expensive WDM devices. For applications beyond 10km, QSFP28 optical transceivers cannot reach it. Therefore, users have to use 40G QSFP+ optics on 100G switches. But here comes a problem, can I use the QSFP+ optics on the QSFP28 port of the 100G switch? If this is okay, can I use the QSFP28 modules on the QSFP+ port? This article discusses the feasibility of this solution and provides a foundational guidance of how to configure the 100G switches.

For Most Switches, QSFP+ Can Be Used on QSFP28 Port

As we all know that QSFP28 transceivers have the same form factor as the QSFP optical transceiver. The former has just 4 electrical lanes that can be used as a 4x10GbE, 4x25GbE, while the latter supports 40G ( 4x10G). So from all of this information, a QSFP28 module breaks out into either 4x25G or 4x10G lanes, which depends on the transceiver used. This is the same case with the SFP28 transceivers that accept SFP+ transceivers and run at the lower 10G speed.

QSFP+ can work on the QSFP28 ports

A 100G QSFP28 port can generally take either a QSFP+ or QSFP28 optics. If the QSFP28 optics support 25G lanes, then it can operate 4x25G breakout, 2x50G breakout or 1x100G (no breakout). The QSFP+ optic supports 10G lanes, so it can run 4x10GE or 1x40GE. If you use the QSFP transceivers in QSFP28 port, keep in mind that you have both single-mode and multimode (SR/LR) optical transceivers and twinax/AOC options that are available.

In all Cases, QSFP28 Optics Cannot Be Used on QSFP+ Port

SFP+ can’t auto-negotiate to support SFP module, similarly QSFP28 modules can not be used on the QSFP port, either. There is the rule about mixing optical transceivers with different speed—it basically comes down to the optic and the port, vice versa. Both ends of the two modules have to match and form factor needs to match as well. Additionally, port speed needs to be equal or greater than the optic used.

How to Configure 100G Switch

For those who are not familiar with how to do the port configuration, you can have a look at the following part.

  • How do you change 100G QSFP ports to support QSFP+ 40GbE transceivers?

Configure the desired speed as 40G:
(config)# interface Ethernet1/1
(config-if-Et1/1)# speed forced 40gfull

  • How do you change 100G QSFP ports to support 4x10GbE mode using a QSFP+ transceiver?

Configure the desired speed as 10G:
(config)# interface Ethernet1/1 – 4
(config-if-Et1/1-4)# speed forced 10000full

  • How do you change 100G QSFP ports from 100GbE mode to 4x25G mode?

Configure the desired speed as 25G:
(config)# interface Ethernet1/1 – 4
(config-if-Et1/1-4)# speed forced 25gfull

  • How do you change 100G QSFP ports back to the default mode?

Configure the port to default mode:
(config)# interface Ethernet1/1-4
(config-if-Et1/1)# no speed

Note that if you have no experience in port configuration, it is advisable for you to consult your switch vendor in advance.

Conclusion

To sum up, QSFP+ modules can be used on the QSFP28 ports, but QSFP28 transceivers cannot transmit 100Gbps on the QSFP+ port. When using the QSFP optics on the QSFP28 port, don’t forget to configure your switch (follow the above instructions). To make sure the smooth network transmission, you need to ensure the connectors on both ends are the same and no manufacturer compatibility issue exists.

Related Article: QSFP+ to SFP+ Adapter (QSA Adapter) Vs. QSFP+ to SFP+ Breakout Cable
Deploy 100 Gigabit Ethernet Network With QSFP28

QSFP 100G PSM4 S to Address 500m Links in Data Center

QSFP 100G PSM4 s optics is a type of 100G QSFP28 single mode transceiver that provides a low-cost solution to long-reach data center optical interconnects. 100G PSM4 (parallel single mode 4 lane) standard is mainly targeted to data centers that based on a parallel single mode infrastructure for a link length of 500 m. Compared with the hot-selling 100G-SR4 and 100G-LR4 optics, QSFP 100G PSM4 s recently wins the popularity among the overall users. This article will provide a complete specification of the QSFP 100G PSM4 s transceiver and explain the reason why people would need QSFP 100G PSM4 s.

QSFP28 module

QSFP 100G PSM4 s—A Low-Cost but Long-Reach 100G Single Mode Transceiver

QSFP 100G PSM4 s is compliant with 100G PSM4 MSA standard, which defines a point-to-point 100 Gb/s link over eight parallel single mode fibers (4 transmit and 4 receive) up to at least 500 m. PSM4 uses four identical lanes per direction. Each lane carries a 25G optical transmission. The 100G PSM4 standard is now available in QSFP28 and CFP4 form factor. Table 2 shows the diagram of the QSFP 100G PSM4 s specification. 100G PSM4 is a low-cost solution. Its cost structure is driven by the cost of the fiber and the high component count. FS.COM offers the Cisco compatible QSFP 100G PSM4 s at US$750.00.

diagram of qsfp 100g psm4 s

As you can see in the above image, QSFP 100G PSM4 s transceiver uses four parallel fibers (lanes) operating in each direction, with transmission distance up to 500 meters. The source of the QSFP 100G PSM4 s module is a single uncooled distributed feedback (DFB) laser operating at 1310 nm. It needs either a directly modulated DFB laser (DML) or an external modulator for each fiber. The 100GBASE-PSM4 transceiver usually needs the single mode ribbon cable with an MTP/MPO connector.

Why Do We Need QSFP 100G PSM4 s?

100G PSM4 is the 100G standard that has been launched by multi-source agreement (MSA) to enable 500m links in data center optical interconnects. But as we all know, there are several popular 100G interfaces out there on the market, such as QSFP28 100GBASE-SR4, QSFP28 100GBASE-LR4, QSFP28 100GBASE-CWDM4, and CFP 100GBASE-LR4, etc. So with so many options, why do we still need QSFP 100G PSM4 s?

To better help you make up your mind, you need to figure out the following questions:

Q1: What are the net link budget differences between PSM4, SR4, LR4 and CWDM?
Table 3 displays the detailed information about these 100G standards.

100GBASE-PSM4 100GBASE-CWDM4 100GBASE-SR4 100GBASE-LR4
4-wavelength CWDM multiplexer and demultiplexer No need Need No need Need
Connector MPO/MTP connector Two LC connectors MPO/MTP connector Two LC connectors
Reach 500 m 2 km 100 m 10 km

Note: the above diagram excludes the actual loss of each link (it is the ideal situation). In fact, WDM solution are at least 7 db worse link budget than PSM4. For a 2 km connectivity, a CWDM module will have to overcome about 10 db additional losses compared to PSM4. And the 100G LR4 optics at 10 km is 12 db higher total loss than PSM4.

Q2: What power targets are achievable for each, and by extension what form factors?
According to the IEEE data sheet, the WDM solutions cannot reasonably fit inside QSFP thermal envelop, while PSM4 can fit inside the QSFP thermal envelope. That means you would need the extra power for the WDM solution of your network. But if you use the QSFP PSM4, this won’t be a problem.

All in all, a QSFP 100G PSM4 s transceiver with 500m max reach is a optional choice for customers. Because other 100G optics are either too short for practical application in data center or too long and costly. QSFP 100G PSM4 s modules are much less expensive than the 10 km, 100GBASE-LR4 module, and support longer distance than QSFP 100G PSM4 s.

Summary

QSFP 100G PSM4 s is the lowest cost solution at under one forth the cost of either WDM alternatives. QSFP 100G PSM4 s can support a link length of 500 m, which is sufficient for data center interconnect applications. QSFP 100G PSM4 s also offers the simplest architecture, the most streamlined data path, higher reliability, an easy upgrade path to 100G Ethernet.

How to Clean a Fiber Optic Transceiver?

To ensure the high performance of optical data transmission, fiber optic cleaning is regarded as an essential way to get rid of the contaminants on devices. Fiber optic connectors are often recommended to be cleaned on a regular basis. Apart from the connectors, other devices such as fiber optic transceiver, optical adapter should also be cleaned when they are being polluted. This post will focus on introducing the proper method of cleaning fiber optic transceivers.

How to Find a Contaminated Optical Transceiver?

Compared with connectors, transceiver modules seem to have a smaller chance to be contaminated. Therefore, fiber optic transceivers should only be cleaned when problems occur. Generally, if signal output from the transceiver is still false or in low-power after cleaning the connectors, you can clean the fiber optic transceiver instead to solve the issue. Common contaminant in optical transceivers is the debris or particles coming through the contact with optical connector ferrules. The following picture shows the comparison of dirty and clean interfaces of transceivers under the digital microscope.

fiber optic transceiver contaminants

Cleaning Tools

Air duster and lint-free swab are the major cleaning tools for fiber optic transceivers. Air duster uses the clean dry air to blow any dust and debris out of the transceiver. Lint-free swab is special for not leaving any lint in the transceiver interface after cleaning.

cleaning tools

Things to Note Before Cleaning

A safe operation is very important to protect yourself from unnecessary accidents. Before starting the cleaning process, here are some precautions for you to note.

  • Always handle optical modules in an ESD (electro-static discharge) safe area using the proper safety precautions.
  • Ensure that the module power is off and handle the modules with care.
  • Always use CDA or an approved canned compressed air supply.
  • Always hold the can of compressed air upright. Tipping may release liquids in the air stream.
  • Do not touch the inner surfaces of the module including the OSA (optical subassemblies), or insert any foreign objects into the ports.
  • Use of finger cots or powder free surgical gloves is not required but can ensure better cleanliness.
Cleaning Procedures

After every thing is ready, you can start to clean the transceiver interface. The followings are the general cleaning steps for reference. If condition permits, you can use microscope to inspect the transceiver to ensure cleanliness. Usually, when output signal becomes normal, then the cleaning procedure is a success.

  • Step 1: Open the dust cover or remove the dust plug from the module.
  • Step 2: Use a non-abrasive cleaner (air duster) to remove any dirt or debris.
  • Step 3: Insert a lint-free cleaning stick of the appropriate size (2.5 mm or 1.25 mm) and turn clockwise. It is recommended to do dry cleaning instead of wet cleaning by using alcohol-based cleaning sticks.
  • Step 4: Repeat steps 2 and 3 if necessary.
  • Step 5: Remove the cleaning stick, and reinsert the module’s dust cap. Always keep the dust cap inserted in the module when not in use.
  • Step 6: Always make sure that the connector is also clean before plugged into the module.
Conclusion

Fiber optic cleaning plays an important role in fiber optic system. Although optical transceivers are less frequent to be cleaned, the request for cleaning still exists. As long as you use the correct cleaning tools and follow the right cleaning procedures, transceivers can surely be cleaned with no more contamination. In this case, the efficiency of fiber optic system will be greatly improved.

Getting to Know About DWDM Tunable Transceiver

DWDM (Dense Wavelength Division Multiplexing) technology offers a great way to boost channel capacity and transmission speed for optical systems. And it has been used in many applications, especially in long haul transmissions. In these applications, DWDM optic transceiver plays an important role. This post intends to introduce a special kind of DWDM transceiver—DWDM tunable transceiver.

What Is a DWDM Tunable Transceiver?

DWDM tunable transceiver is a unique transceiver that can select the channel or “color” the laser emits. Put it in simple terms, most WDM systems generally use optical transceivers with a fixed wavelength. That means there is a spare for each wavelength in use. But tunable transceiver has the capacity to adjust the wavelength of the transceiver on-site to meet different requirements. That’s the most distinguished point of tunable transceivers. Another characteristic of tunable transceivers is that the tunable function only lies in DWDM system due to the dense wavelength grid of DWDM.

Typically the tunable transceivers are for the C-band 50GHz. Around 88 different channels can be set with intervals of 0.4nm, which is the 50GHz band. These optics usually start from channel 16 up to 61 but this depends on the manufacturer’s router/switch and which channels it supports. And the transmission distance of DWDM tunable transceiver over single mode fiber is up to 80km and data speed is up to 10Gbps.

In addition, the DWDM tunable transceivers are available for a wide range of equipment like routers, switches and servers. With these transceivers, network operators can change wavelengths unlimited within the C-band DWDM ITU grid.

Types of DWDM Tunable Transceiver

In today’s market, there are mainly two kinds of DWDM tunable transceivers.

DWDM Tunable XFP transceiver

Tunable XFP transceiver are manufactured with an integrated full C-band tunable transmitter and a high performance receiver. Wavelengths can be set as default in 50GH DWDM ITU grid. The maximum distance of this transceiver on a single mode fiber is up to 80km. In the market, different manufactures may name tunable XFP transceiver in different forms. For example, Cisco may name it as “ONS-XC-10G-C” while Juniper version is “XFP-10G-CBAND-T50-ZR”. Besides, this transceiver be tuned in different ways.

10g dwdm tunable xfp transceiver

DWDM Tunable SFP+ Transceiver

As one kind of DWDM SFP+ module, the tunable SFP+ optical transceiver is a full duplex serial electric, serial optical device. Its transmit and receive functions are contained in a single module that provides a high-speed serial link at 9.95 to 11.3Gbps signaling rates. And the transceiver supports the enhanced SFP+ specification. Here is a simple picture showing its working process.

SFP plus tunable transceiver

On the transmit side, the serial data are passed from the electrical connector to a modulator driver. The modulator driver modulates a C-band cooled tunable transmitter, enabling data transmission over up to 80km on single mode fiber through an industry standard LC connector. On the receive side, the 10G optical data stream is recovered from an APD through a transimpedance amplifier to the electrical connector.

Benefits of DWDM Tunable Transceiver

Tunable transceivers have progressed rapidly in recent years. They have become popular in DWDM transmission systems because of their multi-faceted abilities and ease of spare use. Especially when combined with ROADM (reconfigurable optical add-drop multiplexers), DWDM tunable transceivers become a powerful transmission component. In simple terms, DWDM tunable transceivers have benefits below.

  • A wide tuning range. Compared with common fixed wavelength optical transceivers, DWDM tunable transceivers can save time and money in the long run.
  • Be more suitable for 100G systems by reducing line-width. The ability to adjust wavelengths provides more convenience to fit different transmitting needs.
  • Tunable lasers are capable of switching wavelengths in just nanoseconds. Tunable laser is a vital part of tunable transceivers. It is a high-speed and high-performance optics, enabling the needed wavelength to be reprogrammed in seconds.
Summary

DWDM tunable transceivers are able to function on various wavelengths and to adjust wavelengths according to users’ needs, making them prevalent among DWDM systems. This article mainly introduces the basis and two types of DWDM tunable transceivers. If you want to know more about it, please visit FS.COM.

Related Articles:

Wavelength Switching Solution: Tunable XFP Transceiver

Why Use Tunable DWDM SFP+ Transceivers?

DWDM Tunable SFP+ VS. DWDM Fixed Wavelength SFP+ Transceiver

Things You Need to Know About DWDM Transceiver

In optical communications, DWDM (Dense Wavelength Division Multiplexing) technology enables a number of different wavelengths to be transmitted on a single fiber, which makes it a popular choice among many different areas such as local area networks (LANs), long-haul backbone networks and residential access networks. In these transmission processes, DWDM transceivers play an important role. Here is a brief introduction to them.

Basics of DWDM Transceiver

DWDM transceiver, as its name shows, is a kind of fiber optic transceiver based on DWDM technology. As mentioned above, it enables different wavelengths to multiplex several optical signals on a single fiber without requiring any power to operate. And these transceivers are designed for high-capacity and long-distance transmissions, supporting to 10 Gbps and spanning a distance up to 120 km. Meanwhile, the DWDM transceivers are designed to Multi-Source Agreement (MSA) standards in order to ensure broad network equipment compatibility.

The basic function of DWDM transceiver is to convert the electrical signal to optical and then to electrical signal, which is as same as other optical transceivers. However, based on DWDM technology, DWDM transceiver has its own features and functions. It’s intended for single-mode fiber and operate at a nominal DWDM wavelength from 1528.38 to 1563.86 nm (Channel 17 to Channel 61) as specified by the ITU-T. And it is widely deployed in the DWDM networking equipment in metropolitan access and core networks.

Common Types of DWDM Transceiver

There are different types of DWDM transceiver according to different packages such as DWDM SFP transceiver, DWDM SFP+ transceiver, DWDM XFP transceiver, DWDM XENPAK transceiver and DWDM X2 transceiver. Here is a simple introduction to them.

DWDM SFP Transceiver

DWDM SFP transceiver is based on the SFP form factor which is an MSA standard build. This transceiver provides a signal rate range from 100 Mbps to 2.5 Gbps. Besides, DWDM SFP transceiver meets the requirements of the IEE802.3 Gigabit Ethernet standard and ANSI fibre channel specifications, and are suitable for interconnections in Gigabit Ethernet and fibre channel environments.

dwdm-sfp

DWDM SFP+ Transceiver

DWDM SFP+ transceiver, based on the SFP form factor, is designed for carriers and large enterprises that require a flexible and cost-effective system for multiplexing and transporting high-speed data, storage, voice and video applications. The maximum speed of this transceiver is 11.25G. It’s known to all that DWDM enables service providers to accommodate hundreds of aggregated services of sub-rate protocol without installing additional dark fiber. Therefore, DWDM SFP+ transceiver is a good choice for 10G highest bandwidth application.

dwdm-sfp-plus

DWDM X2 Transceiver

DWDM X2 Transceiver is a high performance serial optical transponder module for high-speed 10G data transmission applications. The module is fully compliant to IEEE 802.3ae standard for Ethernet, which makes it ideally suitable for 10G rack-to-rack applications.

dwdm-x2

DWDM XFP Transceiver

DWDM XFP transceiver is based on the XFP form factor which is also an MSA standard build. The maximum speed of this transceiver is 11.25G and it is usually used in 10G Ethernet. This transceiver emits a specific light. And there are different industry standards and the 100Ghz C-band is the most used one which has a spacing of 0.8 nm. What’s more, DWDM XFP supports SONET/SDH, 10GbE and 10 Gigabit fibre channel applications.

dwdm-xfp

DWDM XENPAK Transceiver

DWDM XENPAK transceiver is SC duplex receptacle module and is designed for backbone Ethernet transmission systems. It is the first 10GbE transceiver ever to support DWDM. And it can support 32 different channels for transmission distance up to 200 km with the aid of EDFAs. DWDM XENPAK transceiver allows enterprise companies and service providers to provide scalable and easy-to-deploy 10 Gigabit Ethernet services in their networks.

dwdm-xenpak

Applications of DWDM Transceiver

As the growing demand of bandwidth, DWDM technology is becoming more and more popular. And DWDM transceivers are commonly used in MANs (metropolitan area networks) and LANs. Different types of DWDM transceiver have different applications. For example, DWDM SFP transceivers are applied in amplified DWDM networks, Fibre Channel, fast Ethernet, Gigabit Ethernet and other optical transmission systems, while DWDM XFP transceivers are usually used in the fields which meet the 10GBASE-ER/EW Ethernet, 1200-SM-LL-L 10G Fibre Channel, SONET OC-192 IR-2, SDH STM S-64.2b, SONET OC-192 IR-3, SDH STM S-64.3b and ITU-T G.709 standards.

Conclusion

In summary, DWDM transceiver is an essential component in DWDM systems. Fiberstore offers various DWDM transceivers and is able to provide the advanced technology and strong innovative capability to produce the best optical components for DWDM systems. If you are interested in our products, please visit FS.COM for more detailed information.