Spend Less on Building 100GbE Network With QSFP28 AOC

Currently 10GbE and 40GbE network are efficient and enough for some users. However, to some large-scale data centers, 40GbE Internet speed can’t meet their demands as the Internet continues to grow in size and traffic. According to research predicts, global data center Internet protocol traffic will grow by 31% every year within next five years. So 100GbE technology will become the mainstream in the near future. Cisco, Juniper, Arista provide 100GbE switches, routers and supported QSFP28 transceiver, QSFP28 AOC. But many enterprises still can’t upgrade to 100GbE network since the switch and QSFP28 AOC are quite expensive. Don’t worry about the high cost. This article will help you find a way to spend less on building 100GbE network with QSFP28 AOC.

QSFP28 AOC

100GbE QSFP28 AOC is composed of an OM4 multimode cable connecting two QSFP28 connectors on each end. The form factor design is easy for plugging and removal. The QSFP28 AOC is compliant to the QSFP MSA (multi-source agreement). QSFP28 AOCs support 100G QSFP28 standards and are available in various lengths (usually from 1-30 meters). 100G QSFP28 AOCs provide an affordable low-power alternative to interconnect 100G QSFP28 ports in data center applications. It’s useful for simplified intra rack and inter rack configurations. The following table lists 100GbE QSFP28 AOC of several famous brands.

Brands	QSFP28 AOC	Price
Cisco	QSFP-100G-AOC (1m-30m)	Above US$ 1,000
Arista	AOC-Q-Q-100G (1m-30m)	Above US$ 3,000
Juniper	JNP-QSFP28-AOC (1m-30m)	Above US$ 2,000
FS.COM	QSFP28 AOC (1m-30m)	From US$ 540 to US$ 630

Table 1. QSFP28 AOC Price Comparison

Switches Supporting QSFP28 AOC

Cisco, Arista, Juniper are three famous fiber optic transceiver manufactures. Transceiver modules and switches of these brands are very common in the market. As the demand for 100GbE data center keeps moving, these manufactures produce switches including 100GbE QSFP28 ports. Here I list four switches which can support QSFP28 AOC, Cisco Nexus 7700, Arista 7500R, Juniper QFX5110 and FS.COM S5850-48S2Q4C.

• Cisco Nexus 3232C—The Cisco Nexus 3232C switch is a low latency, dense, high-performance 100GbE switch designed for data center. It can not only meet customers’ current network needs but also suitable for future applications such as big data, cloud and virtualization. Each of 32 100GbE QSFP28 ports can operate at 10, 25, 40, 50, 100 GbE.
• Arista 7500R—Arista 7500R switches (7500R-36CQ, 7500R-36Q, 7500R-48S2CQ) is designed to lower power per 100GbE port and produce more reliable and dense network. The switches are available in a compact system design of 12, 8 and 4 slot. 7500R-36CQ has 36-port 100GbE QSFP line card. 7500R-36 owns 1/10GbE line card with two 100GbE QSFP28 ports. 7500R-48S2CQ is available with up to 6 100GbE QSFP28 ports.
• Juniper QFX5110—Juniper provides two switches with 100GbE port: QFX5110-48S and QFX5110-32Q. QFX5110-48S is a 10GbE/100GbE data center access switch offering 48x10GbE SFP+ port and 4x100GbE QSFP28 ports. QFX5110-32Q offers up to 32x40GbE QSFP+ ports, or 20x40GbE QSFP+and 4x QSFP28 ports.
• FS.COM offers two switches for 100GbE network: S5850-48S2Q4C and S8050-20Q4C. S5850-48S2Q4C provides 48x10GbE SFP+ ports, 2x40GbE QSFP+ ports and 4x100GbE QSFP28 ports. S8050-20Q4C has 2x40GbE QSFP+ ports and 4x100GbE QSFP28 ports.

Switch Brands	Model	Supported QSFP28 AOC	Switch Price
Cisco	Nexus 3232C	QSFP-100G-AOC (1m-30m)	About US$ 19,500.00
Arista	7500R-36CQ	100GBASE-AOC(3m to 30m)gggg	Average US$ 60,000.00
	7500R-36Q
	7500R-48S2CQ
Juniper	QFX5110-48S	QSFP28 AOC (10 m)gg	Above US$ 16,500.00
	QFX5110-32Q
FS.COM	S5850-48S2Q4C	Generic QSFP28 AOC (1m-30m)	US$ 6,900.00
	S8050-20Q4C

Table 2. Price Comparison of Switches Supporting QSFP28 AOC

Spend Less With FS.COM Switches and QSFP28 AOC

Based on Table 1 and Table 2, to build a 100GbE network with QSFP28 AOC will cost a lot, especially when you require for products from Cisco, Arista and Juniper manufacturers. By comparison, you can see the price of FS.COM switches for 100GbE network and QSFP28 AOC is quite lower. So FS.COM can help you spend less on building 100GbE network with QSFP28 AOC. But if you have already owned Cisco, Arista or Juniper switches, you can buy compatible QSFP28 AOCs which are more cost-effective and have been tested to assure 100% compatibility.

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

How to Convert SFP+ to 10GBASE-T/RJ45?

When migrating to 10G data center, you may have two choices: SFP+ or 10GBASE-T technology. 10GBASE SFP+ interface has always been widely deployed for 10 Gigabit ToR (top of rack) witches due to low power consumption. Due to advanced technology, switch manufacturers significantly reduce the power consumption and cost of 10GBASE-T server and switch. According to some researches, the cost of 10GBASE-T (RJ45 interface) switches is much lower than that of SFP+ switches. So many users prefer to add 10GBASE-T/RJ45 switches. But the problem is how to convert SFP+ to RJ45 port. This article will to introduce a necessary optical equipment–SFP+ to RJ45 media converter.

Introduction to SFP+ to RJ45 Media Converter

The secret to realize SFP+ to RJ45 conversion is 10 Gigabit SFP+ to RJ45 media converter. This converter has one 10G pluggable SFP+ port and one RJ45 port. SFP+ port is compatible with any SFP+ transceiver such as 10G SR SFP, 10G LR SFP and so on, which is the best suitable for your network and link lengths. 10 Gigabit SFP+ to RJ45 media converter is a cost-effective way to convert copper to fiber, or fiber to copper. Since it can deliver fast and reliable network access at longer distances than copper-based networks, it’s ideal for the applications in server rooms, workstations in remote areas or in other buildings.

How to Convert SFP+ to RJ45?

As the following figure shows, existing ToR switch only has some SFP+ interfaces. This switch is connected to an aggregation switch in the data center with multimode fiber patch cords. And the servers below are connected to the ToR switch with twinax DAC cables. Now considering that 10GBASE-T servers are less expensive, we decide to add new 10GBASE-T servers to the rack. Then we face a problem: how to integrate 10GBASE-T RJ45 ports servers into the the rack? To deal with this problem, we need to add 10 Gigabit Ethernet media converters to this rack system. First, connect the media converter with existing ToR switch by inserting one end of twinax DAC cables into the SFP+ port of the 10 Gigabit Ethernet media converter. Second, connecting media converter with the new 10GBASE-T servers by plugging Ethernet patch cords (better Cat6a) into RJ45 port of this media converter and 10GBASE-T servers.

As the 10GBASE-T servers are connected to 10 Gigabit SFP+ to RJ45 media converters over short Ethernet patch cords, so we can enjoy the advantage of 10GBASE-T short reach mode, which means all devices can operate at lower transmit power. Short reach mode, specified in the IEEE 10GBASE-T standard, conserves energy and produces less heat.

FS.COM SFP+ to RJ45 Media Converter Solutions

Part number	Description
21024	1x 10GBase-T to 1x 10GBase-X SFP+, Unmanaged
35609	1x 10GBase-T to 1x 10GBase-X XFP Unmanaged
35432	1x 10GBase-T to 1x 10GBase-X SFP+, Card Type
35433	1x 10GBase-T to 1x 10GBase-X XFP, Card Type
35610	1x 10GBase-T to 1x 10GBase-X SFP+ Managed
35431	1x 10GBase-T to 1x 10GBase-X XFP Managed

Conclusion

SFP+ to RJ45 conversion may be a very common issue in 10G data center. To solve this problem, the most cost-effective way is SFP+ to RJ45 media converter. It can bridge the interface disparities between equipment with 10GBASE-T RJ45 ports and existing rack servers or switches with fiber optic ports. FS.COM offers various high-performance 10G SFP+ to RJ45 media converters. For more product details, please contact us via email sales@fs.com.

Related article: 10G SFP or 10GBASE-T SFP for 10GbE Network?

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

How to Understand Tx Power and Rx Power of a Fiber Transceiver?

As we all know, single mode fiber optic transceiver is designed for long distance data transmission and multimode fiber optic transceiver is for short distance link. How to calculate the specific distance that a fiber optic transceiver can support at a certain occasion? What factors are crucial to the transmission distance? Do you have any idea of Tx (transmit) power and Rx (receive) power level of a fiber optic transceiver? This article will show you by introducing 10GBASE-SR SFP+ and 10GBASE-LR SFP module.

Tx Power and Rx Power of a Fiber Transceiver

First, let’s understand the most two important factors of the fiber optic transceiver: Tx power and Rx power. The optical Tx power is the signal level leaving that device and it should be within the transmitter power range. The Rx power is the incoming signal level being received from the far end device and it should fall within the receive power range.

10GBASE-SR SFP+ is a multimode fiber transceiver and can support the distance of 300 m over OM3 multimode fiber patch cable. While 10GBASE-LR SFP module is a single mode type and can run the network distance up to 10 km over single mode fiber patch cords. Before purchasing 10GBASE SFP+ module, you must carefully read the product details. The following lists the product details about 10GBASE-SR SFP+ and 10GBASE-LR SFP module from Fiberstore. As showing below, Tx power of this Cisco compatible 10GBASE-SR SFP+ is between -7.3 dB and 1 dB. The maximum receive power is below -11.1 dB. With regard to Cisco compatible 10GBASE-LR SFP module, Tx power is from -8.2 to 0.5 dB and the maximum Rx power is -14.4 dB

Tx Power and Rx Power of 10GBASE-SR SFP+

Tx Power and Rx Power of 10GBASE-LR SFP+ Module

 

Tx Power and Rx Power VS. Optical Power Budget

To calculate the specific distance of a fiber optic transceiver, we need to know its optical power budget (maximum allowable loss).

Optical power budget = Tx power - Rx power

Therefore, according to the Tx power and Rx power, we can calculate the maximum allowable loss of 10GBASE-SR SFP+ and 10GBASE-LR SFP module.

Optical Power Budget of 10GBASE-SR SFP+

Min Tx Power = -7.3 dB
Max Rx Power = -11.1 dB
Optical power budget (maximum allowable loss) = (-9.5 dB) - (-11.1 dB)=1.6 dB

Optical Power Budget of 10GBASE-LR SFP+ Module

Min Tx Power = -8.2dB
Max Rx Power = -14.4 dB
Optical power budget (maximum allowable loss) = (-8.2 dB) - (-14.4 dB)=6.2 dB

Tx Power and Rx Power VS. Transmission Distance

Except optical power budget, we have to consider other factors including the link length, fiber optical connectivity components, fusion splicing points and some unpredictable fiber attenuation caused by fiber patch cable bending (usually the attenuation is about 3 dB). The loss of each connector is 0.6 dB and 0.1 dB of each fusion splicing point. Suppose we use 10GBASE-LR SFP+ module to build a network covering 2 connectors, 4 fusion splicing points. This module is interfaced with LC single mode fiber patch cord. If the single mode fiber cable has the wavelength of 1310 nm, the cable loss is about 0.35 dB per kilometer.

The worst optical loss = Power Budget – Total Optical Power Loss=6.2 dB - 1.2dB (2x0.6 dB) - 0.4dB (0.1x4) - 3dB (safety factor) = 1.6 dB

Worst case distance = {Worst case OPB, in dB} / [Cable Loss, in dB/km]=1.6dB/0.35dB/km
So we can get 10GBASE-LR SFP+ module can support at least 4.57 km at this occasion. Data transmission distance is mainly influenced by the optical power budget and fiber cable loss. From the above content, the optical power budget of 10GBASE-SR SFP+ is smaller than that of 10GBASE-LR SFP+ module. The more the optical power budget, the further the fiber transceiver can support. What’s more, the cable loss of multimode fiber cable is larger than that of single mode fiber cable. Obviously 10GBASE-LR SFP+ module can support longer link distance than 10GBASE-SR SFP+.

Note: The optical power budget is based on a theoretical calculation, and is just for reference. The transmission distance should be calculated based on the power budget of fiber transceiver module tested on the switch and some practical attenuation.

Conclusion

Tx power and Rx power level of a transceiver are the main factors of transmission distance. The more the optical power budget, the better the transceiver. Before purchasing a transceiver, you’d better calculate the optical power budget according to transceiver module details.

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