Difference Between QSFP, QSFP+, QSFP28

SFP is short for small form factor. It refers to fiber optic transceivers supporting 1Gbps data rate. Except SFP, current market is full of various types of fiber optic transceivers, such as QSFP, QSFP+ and QSFP28. At the first sight, these transceiver modules are very similar. But actually, they have big differences. To know the difference clearly is good to make the right choice for your network connection. So what are the differences between QSFP,  QSFP+, QSFP28?

QSFP vs QSFP+

“Q” of QSFP means quad (4 channels). QSFP is a compact, hot-pluggable transceiver used for data communications. The QSFP specification supports Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. QSFP transceivers support the network link over singlemode or multimode fiber patch cable. QSFP modules are commonly available in several different types: 4x1G QSFP, 4x10G QSFP+, 4x28G QSFP28. From this side, QSFP vs QSFP+ vs QSFP28 all share the same small form-factor. literally QSFP uses 4x1G lanes and was only found in some FC/IB contexts.

While QSFP+ transceivers, evolving from 4x1G lanes (QSFP) to 4x10G lanes, are designed to support 40G Ethernet, Serial Attached SCSI, QDR (40G) and FDR (56G) Infiniband, and other communications standards. QSFP+ standard is the SFF-8436 document which specifies a transceiver mechanical form factor with latching mechanism, host-board electrical-edge connector and cage. QSFP+ modules integrates 4 transmit and 4 receive channels plus sideband signals. Then QSFP+ modules can break out into 4x10G lanes. QSFP+ modules are used to connect switches, routers, Host Bus Adapters (HBAs), enterprise data centers, high-performance computing (HPC) and storage. But some may think QSFP as the same with QSFP+, especially in the Ethernet world.

QSFP+ vs QSFP28

QSFP+ and QSFP28 differs in “28” as the name says. QSFP28 is a hot-pluggable transceiver module designed for 100G data rate. QSFP28 integrates 4 transmit and 4 receiver channels. “28” means each lane carries up to 28G data rate. QSFP28 can do 4x25G breakout connection, 2x50G breakout, or 1x100G depending on the transceiver used. While QSFP+ supports the data rate of 40G, 4 channels for transmitting and 4 channels for receiving, each lane carrying 10G. QSFP+ can break out into 4x10G or 1x40G connection.

Usually QSFP28 modules can’t break out into 10G links. But it’s another case to insert a QSFP28 module into a QSFP+ port if switches support. At this situation, a QSFP28 can break out into 4x10G like a QSFP+ transceiver module. One thing to note is that you can’t put a QSFP+ transceiver into a QSFP28 port to avoid destroying your optics.

FS.COM QSFP+ vs QSFP28

Compatible with major brands such as Cisco, Juniper, Arista, Brocade, etc., FS.COM QSFP+ and QSFP28 modules can support both short and long-haul transmission. Here lists our generic QSFP+ and QSFP28 modules in the following table.

FS.COM Generic QSFP+

Model	Description	Price List	In Stock
17931	40GBASE-SR4 QSFP+ 850nm 150m MPO Transceiver for MMF	US$ 49.00	1061 pcs
34917	40GBASE-PLRL4 QSFP+ 1310nm 2km MPO Transceiver for SMF	US$ 220.00	49 pcs
24422	40GBASE-LR4 and OTU3 QSFP+ 1310nm 10km LC Transceiver for SMF	US$  340.00	50 pcs
34912	40GBASE-CSR4 QSFP+ 850nm 400m MPO Transceiver for MMF	US$  70.00	141 pcs
35205	40GBASE-UNIV QSFP+ 1310nm 2km LC Transceiver for SMF&MMF	US$  340.00	18 pcs
34913	40GBASE-LR4L QSFP+ 1310nm 2km LC Transceiver for SMF	US$ 340.00	44 pcs
48721	40GBASE-SR Bi-Directional QSFP Module for Duplex MMF	US$  300.00	106 pcs
35209	40GBASE-PLR4 QSFP+ 1310nm 10km MPO Transceiver for SMF	US$  380.00	34 pcs
35211	40GBASE-ER4 and OTU3 QSFP+ 1310nm 40km LC Transceiver for SMF	US$  1,500.00	40 pcs
39986	40GBASE-LR4 CFP 1310nm 10km SC Transceiver for SMF	US$  800.00	Available

FS.COM Generic QSFP28

Model	Description	Price List	In Stock
35182	Generic Compatible QSFP28 100GBASE-SR4 850nm 100m Transceiver	US$ 270.00	38 pcs in stock
65216	Generic Compatible QSFP28 100GBASE-PSM4 1310nm 500m Transceiver	US$ 750.00	26 pcs in stock
65214	Generic Compatible QSFP28 100GBASE-CWDM4 Lite 1310nm 2km Transceiver	US$ 1,350.00	26 pcs in stock
65215	Generic Compatible QSFP28 100GBASE-CWDM4 1310nm 2km Transceiver	US$ 1,350.00	26 pcs in stock
39025	Generic Compatible QSFP28 100GBASE-LR4 1310nm 10km Transceiver	US$ 2,800.00	Available

Conclusion

The difference between QSFP vs QSFP+ vs QSFP28 has been stated clearly in this article. Though QSFP is thought as QSFP+, when talking about 40G, actually we mean QSFP+. QSFP+ vs QSFP28 mainly differs in data rate and breakout connection. So you must be sure what you need is 40G QSFP+ or 100G QSFP28 for high density applications, especially when connecting with 10G SFP+.

Originaly published at www.fiber-optic-equipment.com

Preparation for 40G/100G Migration

10G is now common in large enterprises. New network trends continue to drive the demand for high-speed Ethernet, such as the virtualization trend, network storage trend, I/O convergence trend, and data center network aggregation trend. So 40G and 100G as well as corresponding equipment are introduced into the market. The migration from 10G to 40G/100G is inevitable.

IEEE and TIA Standards

Before planning for migration to 40G/100G network, we should better know well about high-speed Ethernet. The following will talk about it from the side of standards. Because structured cabling systems design is always guided first by standards. The standards for 40G and 100G are significantly different from previous generations; active equipment and how information is transmitted are unique.

First, it’s IEEE standards. IEEE creates the standards that define performance parameters. IEEE 802.3ba 40Gb/s and 100Gb/s Ethernet is the only current standard that addresses the physical layer cabling and connector media maximums for 40/100G fiber channel requirements. IEEE 802.3ba-2010 standard was approved at the June 2010 IEEE Standards Board meeting. The standard is shown in the following table.

40G/100G Using MPO/MTP Interface
Second, it’s TIA (Telecommunications Infrastructure Standard). For data centers, TIA defines how to apply the parameters to structured cabling systems. It establishes design criteria including space and layout, cabling infrastructure, tiered reliability, and environmental considerations. The standard recommends using the highest capacity media available to maximize infrastructure lifespan.

1G and 10G networks use GBIC (Gigabit interface converter). For example, generally the transceiver SFP+ (small form-factor pluggable) is for 10G network. Later the fiber connectivity in high-speed active equipment becomes condensed and simplified. Transceivers for 40G and 100G are QSFP (quad small form-factor pluggable), CFP and CXP (100G form-factor pluggable). MPO/MTP is the designated interface for multimode 40/100G, and it’s backward compatible with legacy 1G/10G applications as well. Its small, high-density form factor is ideal with higher-speed Ethernet equipment.

Figure1. MPO/MTP Connector

40G and 100G Ethernet employ parallel optics. Data is transmitted and received simultaneously on MTP interfaces through 10G simplex transmission over each individual strand of the array cable.

After introducing some basics of the high-speed Ethernet, we’ll discuss the structured cabling system of migration to 40G and 100G networks in the simplest and most-effective way.

12- or 24-Fiber Cabling Infrastructure

The system includes configurations for 10G to 40G/100G networks over 12- or 24-fiber MTP cabling. What’s the difference between the two methods? Which one is better? The sections will compare the two from the sides of migration, density and congestion.

Migration To achieve the migration, components like trunks, harnesses, array cords, modules, and adapter plates are needed. With the 40G 12-fiber legacy configurations, a second trunk and another set of array harnesses will be needed to achieve 100% fiber utilization (as shown in Figure 2). For 100G, it also needs these additional components with 12-fiber legacy configuration. But with 24-fiber trunks, a single cable can support a 1G-100G channel and simplify network upgrades immensely (as shown in Figure 3). When equipment is upgraded, there is no need to install new trunks. In addition, limiting changes can reduce the inherent risks to network security and integrity.

Figure2. 12-Fiber Cabling

Figure3. 24-Fiber Cabling

Density The higher density connectivity, the more rack space for active equipment. Thus less floor space is needed. In this way, 24-fiber cabling has the obvious advantage. If the active equipment is configured for 24-fiber channel/lane assignments, there will be twice as as many connections with the same number of ports compared to 12-fiber.

Congestion The more connectivity you are able to run in the same footprint, the more crowded it can become at the rack or cabinet. Fewer trunks reduce cable congestion throughout the data centers. Using 24-fiber MTP trunks for the cable runs will save half the number of cables versus 12-fiber in the network. Runs carry a lighter load, fibers are easier to manage, and improved airflow reduces cooling costs. So 24-fiber MTP trunks offer a huge benefit.

Conclusion

The high-speed network will become more and more popular. It’s very important to know something about the migration to 40G/100G. To upgrade your network, 24-fiber MTP will be a better fiber cabling choice compared with 12-fiber. Do you prepare well for the great migration?

Originally published at www.fiber-optic-equipment.com