QSFP+ to 4xSFP+ AOC and QSFP+ MTP Breakout Cable Solution

Migration from 10G to 40G is an inevitable trend in data center. Migration means you need new QSFP+ transceiver modules, fiber patch cables and other equipment. Common two methods to migrate from 10G to 40G for short distance are QSFP+ to 4xSFP+ AOC and QSFP+ MTP breakout cable solution. When you come across this issue, it’s hard to tell which one is better. This article will introduce their difference and tell you how to make the right decision.

40G QSFP+ to 4xSFP+ AOC

40G QSFP+ to 4xSFP+ AOC (active optical cable) is composed of a QSFP+ connector on one side and four individual SFP+ connectors on the other side. The QSFP+ connector (40Gbps rate) offers four parallel, bidirectional channels and each operates at up to 10.3125 Gbps. The QSFP+ connector can be installed into QSFP+ port on the switch and feed up to four 10G SFP+ links. And the link lengths can reach 100 meters on OM3 fiber. It’s a cost-effective interconnect solution for 40G and 10G switches and servers.

40G QSFP+ to 4xSFP+ Breakout AOC

QSFP+ MTP Breakout Cable

The other common solution for 10G to 40G short distance migration is to use breakout cable and of course corresponding transceivers. How to achieve the connection? You’re gonna need 40GBASE-SR4 QSFP+, MTP to LC breakout cable and 10GBASE-SR SFP+. Here we are going to explain 40GBASE-SR4 QSFP+ and MTP-LC breakout cable in details.

First, 40GBASE-SR4 QSFP+ is designed for 40 Gigabit data center and can support the link length of 100 m and 150 m respectively on laser optimized OM3 and OM4 fiber cables. This module offers 4 independent channels for transmitting and receiving. Each lane is capable of running 10Gbps signal and is compliant to IEEE 10GBASE-SR specification. Connecting with 12-fiber MTP/MPO cables, it can support 40Gbps network. Or combine 40GBASE-SR4 QSFP+ with 4x10G breakout cable and send data to four 10GBASE-SR SFP+.

Second, MTP to LC breakout cable is suitable for high density network. It’s specifically designed for fast Ethernet, fiber channel, data center and gigabit Ethernet application. QSFP+ MTP to LC breakout cable is used for a direct connection between QSFP+ to 4xSFP+ ports with no patch panels or intermediate trunks in between. On one side, it’s an MTP connector with 8 or 12 fibers. On the other side, there are 4 duplex LC connectors. Each fiber cable transmits 10Gbps.

MTP-LC breakout cable

Differences of Two Solutions

Two methods of 10G to 40G migration over short distance have been introduced in above content. Comparing the two different solutions, you can find some obvious differences. The following lists some points for your convenience to make suitable decision.

  • Price—The second solution needs at one QSFP+, 4 SFP+ and an MTP-LC breakout cable. The price of these devices is higher than 40G QSFP+ to 4xSFP+ AOC. So 40G QSFP+ to 4xSFP+ AOC is cheaper.
  • Complexity—The second solution seems more complicated since it needs more optical equipment. You need to order and manage cables.
  • Distance—40G QSFP+ to 4xSFP+ AOC can only support the distance up to 100 m. While using MTP-LC breakout cable, the link distance can reach 150 m over OM4 cable.
Conclusion

You must have a full understanding of these two solutions. 40G QSFP+ to 4xSFP+ AOC is easier and cheaper than MTP to LC breakout cable. If you’re a new technician and have tight budget, you can buy AOC cable. But if you don’t care too much about money, you can select 40GBASE-SR4 QSFP+ and MTP to LC breakout cable to get a little longer link length. Hope this article can help you make the right decision.

Originaly published at http://www.fiber-optic-equipment.com

Does Multimode SFP Work Over Single-mode Fiber Cable?

When you prepare to connect some SFPs with fiber patch cords, you may find SFPs are multimode modules while your fiber cables are single-mode. Try to connect those optics to fiber cable, but no green light and the link fails. So multimode SFPs can’t work over single-mode fiber cables. To avoid the wasting of time and money, you should better know well about single-mode and multimode SFPs and fiber patch cords.

Single-mode and Multimode SFP

SFP, small form factor pluggable transceiver, can support the data rate up to 1Gbps. SFPs can be divided into single-mode and multimode modules.

For single-mode SFPs, there are “LX” for 1310 nm and “EX” “EZX” for 1550 nm. Single-mode SFPs are designed to transmit signals over long distances. For example, Cisco GLC-LH-SM-15 compatible 1000BASE-LX/LH SFP 1310nm 15km DOM transceiver, main product information is shown as follows:

  • Wavelength: 1310 nm
  • Interface: LC duplex
  • Max Cable Distance: 15 km
  • Max Data Rate: 1000Mbps
  • Cable Type: SMF

Comparatively, multimode SFPs are identified with “SX”. This kind of optics is specially for short distance data transmission. For instance, Cisco GLC-SX-MM compatible 1000BASE-SX SFP 850nm 550m transceiver, this is a typical multimode SFP.

  • Wavelength: 850 nm
  • Interface: LC duplex
  • Max Cable Distance: 550m over OM2 MMF
  • Max Data Rate: 1000Mbps
  • Cable Type: MMF

SFP-LX and SFP-SX

Single-mode Fiber Cable and Multimode Fiber Cable

Fiber patch cables are used to connect transceivers on your switch/device. You have to buy the right fiber cable type for your optics. Fiber cable has two different categories: single-mode and multimode.

Generally, single-mode fiber cable can support further distance because of lower attenuation, but the price is higher. While multimode fiber cable has a larger core, usually multimode fiber cable is constructed in 50/125 and 62.5/125. It allows multiple modes of light to propagate. When the light passes through the core, the light reflections increases and more data can be transmitted at given time. As the high dispersion during signal transmission, the link distance gets reduced. So multimode fiber cable is for short distance application. Multimode fiber cable is a little more complex than single-mode fiber cable since it includes four different types of OM1, OM2, OM3, OM4. OM1 and OM2 fiber patch cable can support the data rate up to 10Gbps. OM3 and OM4 are laser optimized so that they can be used in high density data center to support the data rate of 40Gbps and 100Gbps. The following table shows how long each kind of fiber cable can reach running at different data rate.

Fiber Mode Cable Type 1GbE 10GbE 40GbE 100GbE
Single-mode OS2 100km 40km 40km 40km
Multimode OM1 275m(SX) 33m(SR) / /
OM2 550m(SX) 82m(SR) / /
OM3 550m(SX) 300m(SR) 100m 100m
OM4 1000m(SX) 400m(SR) 150m 150m

Note: “SR” implies multimode 10Gpbs SFP+.

For more information about single-mode and multimode fiber cable, you can refer to my previous articles:
What Is Single Mode Fiber?
What Are OM1, OM2, OM3 and OM4?
Solutions for Multimode SFP

If you have Cisco Catalyst 3650 WS-C3650-48PS switches with 4x1G uplink ports, to build a 300m-network link, you are gonna purchase fiber patch cable and SFP modules. What kind of optical equipment should you choose?

As to the SFP module, you need Cisco GLC-SX-MM 1000BASE-SX SFP. Or you can spend less money on third-party SFPs with 100% compatibility. Next step, you need to find suitable fiber patch cable to match this type of SFP. Since 1000BASE-SX SFP is multimode, of course you need multimode fiber cable. Considering the distance of 300 meters, OM1 can only reach 275 meters. So OM2 is the best choice for it’s the cheapest and can reach 550 meters.

1000BASE-SX SFP connection

Conclusion

It’s obvious that multimode SFPs can’t work over single-mode fiber cables. When buying SFPs, watch the standards on the label carefully and find if it’s “SX” or “LX”, “EX”. If it shows “SX”, then find multimode fiber patch cable. It’s not very difficult to choose right cable for your SFP modules.

Originally published at http://www.fiber-optic-equipment.com

Advice on Patch Cable Selection for Optical Transceiver

Fiber optic network connection can’t be achieved without fiber optic transceivers and fiber patch cables. Fiber optic transceivers vary from transmission media, interface, transmission distance, data rate, and brand, for example, SFP for 1000Mbps, SFP+ for 10G, QSFP+ for 40G, CFP and QSFP28 for 100G. It’s not difficult to identify these transceivers. But when you connect the transceiver to the patch cable, many details need to be noticed. This article will give you advice on how to choose the suitable patch cable for your transceivers.

Transmission Media—Copper & Fiber

According to transmission media of fiber optic and copper, transceivers can be divided into two kinds, copper based transceivers and fiber optic based transceivers. MSA has defined several copper based transceiver like: 100BASE-T, 1000BASE-T and 10GBASE-T. Copper transceivers are available in GBIC, SFP and SFP+ form factors, which usually has a RJ45 interface. So Cat5/6/7 cables are typically used to connect with the transceivers. Maybe Cat8 will be researched and developed to support higher data rate up to 40G sooner or later.

transceiver-rj45-interface

As to fiber optic transceivers, things are more complex. For that fiber optic transceivers require different fiber patch cords which have more types. Fiber patch cables cover single-mode and multimode. Single-mode patch cable can be classified into OS1 and OS2. While multimode cables can be divided into OM1, OM2, OM3, OM4 cable. Different cables are used in different applications. Single-mode cable can support long distance transmission and multimode cable for short distance link. If the transmission distance is shorter than 500 meters, multimode patch cable is suggested. For long distance transmission, single-mode transmission is suggested. You fiber-patch-cordsshould also consider that the transmission data rate can also affect the transmission distance. Let’s look at the following point.

Supported Distance and Data Rate

MSA has defined a variety of transceivers that can support different transmission distances and data rates. When you buy a fiber optic transceiver, you will find the data rate, wavelength, distance, etc. on its labeling. The following table show the basic information of most often used transceivers and supported cable type.

Description Wavelengh Data Rate Cable Type Distance
SX 850nm 1G MM 500 m
LX 1310nm 1G SM 8 km
EX 1310nm 1G SM 40 km
ZX 1550nm 1G SM 70 km
SR 850nm 10G MM 300 m
LR 1310nm 10G SM 10 km
ER 1550nm 10G SM 40 km
ZR 1550nm 10G SM 80 km
SR4 850nm 40G MM 100 m
SR10 850nm 100G MM 100 m
LR4 1310nm 40G SM 10 km

As mentioned before, single-mode patch cable is better for long distance transmission and multimode patch cable for short distance transmission. Actually single-mode patch cords can be used for different data rates in both long and short distances. But single-mode fiber optic cable will cost more. To achieve reliable performance in short distances with cost effective solutions, you should know the performance of multimode fiber optic cables. The following chart provides the detailed transmission distances and data rates information for different multimode fiber optic cables over wavelength of 850 nm for your reference.

Fiber Type 1G 10G 40/100G
OM1 300 m 36 m N/A
OM2 500 m 86 m N/A
OM3 1 km 300 m 100 m
OM4 1 km 550 m 150 m
Transceiver Interfaces

The selection of patch cable for transceiver should also consider the interfaces through which patch cords is connected to the transceiver. In addition, transceiver usually used one port for transmitting and one port for receiving. Generally, fiber optic transceivers usually employs duplex SC or LC interfaces. However, for BiDi transceivers only one port is used for both transmitting and receiving. Thus, simplex patch cord is used with BiDi transceiver.

Some 40G/100GBASE QSFP+ transceivers used MTP/MPO interfaces, which should be connected to the network with multi-fiber patch cords attached with MTP/MPO connectors. If these ports are used for 40G to 10G or 100G to 10G connection, then fanout patch cable should be used. For example, a MTP to 8 LC fanout cable can splitter 40G data rate to four 10G data rate.

Summary

Next time when you select patch cords for your fiber optic transceivers, you can consider these factors like transmission media, transmission data rate and distance, transceiver interfaces. FS.COM offers a wide range of fiber optic transceivers and patch cords. Custom service is also available. Any problem, please contact us via sales@fs.com.

Originally published at http://www.fiber-optic-equipment.com