How to Take Full Advantages of Switches in Data Center

During data center upgrading or migration to higher data rate like 40G/100G, the network designer is always pursuing for flexibility. This is because devices or cabling components with great flexibility can not only decrease the cost for upgrading, but also provide more possibilities for the data center in the future. Switch has always been the most important device data center. Thus, a flexible switch should support a variety of transmission media and data rates, which could have significant positive influence during data center upgrading on cabling and costs. IBM G8264 switch is such a switch that is specially designed for data center, which is suggested to be used at layer 2 or layer 3, providing non-blocking line-rate, high-bandwidth switching, filtering, and traffic queuing without delaying data. However, to make full use of these switches, you should select proper connection components and cabling plans. This post will take IBM G8264 switch as an example to illustrate how to take full advantages of the switches in data center.

Understand Your Switch—IBM G8264 Switch

The first step to make full use of a switch is to have a full understanding of the switch you are using. There are many ways to understand your switch. While the most direct method is to understand the ports on the switches. This method also works for IBM G8264 switches. As shown in the following picture, which is the front panel of IBM G8264 switch, the most outstanding part of the switch is the 48 SFP/SFP+ ports. It occupied most space on IBM G8264 switch front panel. These ports can support data rate of 1G/10G. Four QSFP+ ports for 40G are beside these SFP/SFP+ ports. There are three another ports for other use on the from panel: one 10/100/1000 Ethernet RJ45 port for out of band management, one USB port for mass storage device connection and one mini-USE console port for serial access.

IBM G8264 Connection in Data Center

It is clear that IBM G8264 switch can support data rate of 1G, 10G and 40G. The following parts illustrate how to connect IBM G8264 with the target devices in 1G, 10G, and 40G network separately in details. During the cabling in data center, distance is always a factor that cannot be ignored. The transmission distance required, can largely decide the cabling components selection.

1G Connection of IBM G8264 Switch

To accomplish the 1G connection of IBM G8264 switch and target devices, there are several methods according to transmission distance and transmission media (fiber optic or copper). For distance up to 100 meters, RJ-45 1000BASE-T SFP transceivers with UTP Cat5 cables are suggested, cause they are based on copper and is cheaper than fiber optic components. However, if you want reach a longer distance with good transmission quality, it would be better to use fiber optic cable and optical transceiver. By using 1000BASE-SX SFP optical transceivers with multimode fiber, the transmission distance is up to 220 (62.5 μ multimode fiber) meters and 550 meters (50 μ multimode fiber). For long distance transmission, single-mode fiber optic cables are suggested to be used with 1000BASE-LX SFP optical transceivers, which can connect IBM G8264 switch with the target devices that are 10 kilometers far away. The following chart is the detailed product solutions for IBM G8264 1G connection.

Transmission Media	Module	Cable & Connector	Distance
Copper Cable	BN-CKM-S-T: SFP 1000BASE-T copper transceiver	RJ45, Cat5 cable	100 m
Fiber Optic Cable	BN-CKM-S-SX: SFP 1000BASE-SX optical transceiver	LC duplex, MMF	220 m(50μ multimode fiber)
			550 m(62.5μ multimode fiber)
	BN-CKM-S-LX: SFP 1000BASE-LX optical transceiver	LC duplex, SMF	10 km

10G Connection of IBM G8264 Switch

As mentioned, IBM G8264 switch supports 10G configuration. For 10G, there are mainly two methods: using DACs (direct attach cables) or using transceivers and patch cords. The beauty of using DAC is the eliminating of transceivers and reduction of cost. However, the transmission distance is limited to 7 meters by using DACs. If longer distances are required, 10GBASE-SR transceiver used with OM3 multimode fiber can support transmission distance up to 300 meters. If 10GBASE-SR transceiver is used with OM4 fiber optic cable, distance up to 400 meters could be reached. Using 10GBASE-LR transceiver with single-mode fiber optic cable, IBM G8264 switch can be connected with target devices that are 40 kilometers away.

If the 10G ports number cannot satisfy the requirements, the one QSFP+ port on IBM G8264 can be split into four 10G ports, by using QSFP+ DAC breakout cables for distances up to 5 meters. For distances up to 100 meters, optical MTP-to-LC break-out cables can be used with the 40GBASE-SR4 transceiver. Kindly check the following table for IBM G8264 switch 10G cabling components solutions.

Data Rate	Modules	Cable & Connector	Distance
10G-10G Connection	BN-SP-CBL-1M: SFP+ Copper Direct Attach Cable (1 meter)		0.5-7 m
	BN-SP-CBL-3M: SFP+ Copper Direct Attach Cable (3 meter)
	BN-SP-CBL-5M: SFP+ Copper Direct Attach Cable (5 meter)
	BN-CKM-SP-SR: SFP+ 10GBASE-SR Short Range Transceiver	LC duplex, MMF	300 m(OM3)
			400 m(OM4)
	BN-CKM-SP-LR: SFP+ 10GBASE-LR Long Range Transceiver	LC duplex, SMF	40 km
40G-10G Connection	BN-QS-SP-CBL-1M: QSFP+ DAC Break Out Cable (1 meter)		5 m
	BN-QS-SP-CBL-3M: QSFP+ DAC Break Out Cable (3 meter)
	BN-QS-SP-CBL-5M: QSFP+ DAC Break Out Cable (5 meter)
	BN-CKM-QS-SR: QSFP+ 40GBASE-SR Transceiver	MTP-to-LC break-out cables	100 m

40G Connection of IBM G8264 Switch

For 40G connection, both fiber optic connection and copper connection can be built by using different components. A 40GBASE QSFP+ to QSFP+ DAC can provide connection between IBM G8264 and target devices up to 7 meters. With multimode fiber optic cables, distance up to 100 meters (OM3) and 150 meters (OM4) can be reached, when using with 40GBASE-SR4 QSFP+ transceivers. For long distance 40G transmission, 40GBSE-LR QSFP+ transceiver and single-mode fiber optic cable with LC connectors are suggested. Related components for IBM G8264 switch are concluded in the following chart.

Modules	Cable & Connector	Distance
49Y7884: QSFP+ 40GBASE-SR Transceiver	MTP connector, MMF	100 m(OM3)
		100 m(OM4)
00D6222: 40GBASE-LR4 QSFP+ Transceiver	LC connector, SMF	10 km
BN-QS-QS-CBL-1M: QSFP-to-QSFP cable (1 meter)		1-7 m
BN-QS-QS-CBL-3M: QSFP-to-QSFP cable (3 meter)

Conclusion

To make full used of the switches in data center with great flexibility, both the selection of switch and cabling solutions is very important. IBM G8264 as a switch with great flexibility is an ideal solution for data center upgrading to 40G. The above mentioned modules and cables are all provided by FS.COM, which are IBM G8264 compatible and are fully tested on the IBM G8264 switches. Kindly contact sales@fs.com for more details, if you are interested.

This post is originally published in my blog: http://www.fiber-optic-tutorial.com/how-to-take-full-advantages-of-switches-in-data-center.html 

How to Connect Cisco Nexus 9396PX to 40G Network

Both devices and network architecture should be consider during data center upgrade. With the driven of applications like Cloud, Internet of Things, and virtual data center, it is clear that 10G can no longer satisfy the application needs. Migrating to 40/100G is an urgent problem. Cisco Nexus 9396PX switch, as one of the first member of Cisco Nexus 9000 series platform, can support 40G transmission with flexibility and high density. However, the problem is that many customers do not know how to get there to make full use of these devices. This post will give a detailed description about how to connecting Cisco Nexus 9396PX switch to optimized network architecture.

Optimized Network Architecture—Spine-Leaf Architecture

The traditional network usually used a three tier network architecture. However, with the migration of 40/100G, a new architecture is taking place of the traditional one with great advantages. This is known as spine-leaf architecture. Compare with the traditional three tier network architecture, spine-leaf uses a two-tier mode as shown in the above picture. Several most obvious advantages of spine-leaf architecture are list as following:

• spine-leaf network is more adaptable to the continuous change of data center. This is because an additional Spine switch may be added and uplinks may be extended to every Leaf switch, resulting in the addition of interlayer bandwidth and reduction of the oversubscription.
• Spine-leaf network can create high density cabling environments depending on the scale of the network.
• Using a two-tier mode, spine-leaf network can reduce the overall signal latency through the elimination of a switching layer.

Connecting Cisco Nexus 9396PX to 40G Spine-Leaf Network

To make full use of the given source, spine-leaf architecture is suggested. As shown in the above picture, the Cisco Nexus 9396PX is a 2RU non-blocking Layer 2 and 3 fixed switch offering 48 ports of 1G SFP/10G SFP+ and 12 ports of 40G QSFP+. Cisco Nexus 9396PX switch is suggested to be used as the leaf switch in 40G spine-leaf network. Cisco Nexus 9396PX is suggested to be used as leaf switch in 40G spine-leaf network. In spine-leaf network architecture for 40G application, the connections between the spine switches and leaf switches are 40G, while connections between the leaf switches and servers are usually 1/10G. Thus these 40G QSFP+ ports can be used to connect the spine switch and the 1G SFP/10G SFP+ are suggested to connect servers and routers. To accomplish the whole spine-leaf connection, optics and cables or DAC (direct attach cable) should be used. The following picture shows a 40G spine-leaf architecture with Cisco Nexus 9396PX being used in the leaf layer and the fiber cabling choice for Cisco Nexus 9396PX switch in this architecture.

Cisco Nexus 9396PX Cabling Solution

Using the fixed switch Cisco Nexus 9396PX with spine-leaf architecture can greatly increase the network scaling capability and adaptability. Detailed information about modules and cables that can be used with Cisco Nexus 9396PX are listed in the following chart.

Connection	Option 1: Optics & Cable		Option 2: DAC
Spine to leaf (40G connection)	QSFP-40G-SR4	MMF, OM3/OM4, MPO patch cable	QSFP-H40G-AOC (1m to 10m are available) QSFP-H40G-CU (1m to 5m are available) QSFP-H40G-ACU (7m to 10m are available)
	QSFP-40G-SR4-S
	QSFP-40G-CSR4
	QSFP-40GE-LR4	SMF, LC duplex patch cable
	QSFP-40G-LR4
	WSP-Q40GLR4L
	QSFP-40G-LR4-S
	QSFP-40G-ER4
Leaf to server (1/10G connection)	SFP+ Optics		SFP-10G-AOC (1m to 10m are available) SFP-H10GB-CU (1m to 5m are available)
	SFP-10G-SR	MMF, LC duplex patch cable
	SFP-10G-SR-S
	SFP-10G-LR	SMF, LC duplex patch cable
	SFP-10G-LR-S
	SFP-10G-ER
	SFP-10G-ER-S
	SFP-10G-ZR
	DWDM SFP+
	SFP Optics
	GLC-T (1000BASE-T)	RJ-45, Cat 5
	SFP-GE-T
	GLC-SX-MMD	MMF, LC duplex patch cable
	GLC-SX-MM
	GLC-LH-SMD	SMF, LC duplex patch cable
	GLC-EX-SMD
	GLC-LH-SM

All the products mention in this chart can be customized according to your applications in Fiberstore (FS.COM). They will be fully tested in Fiberstore Test Center before they go to the market. Kindly contact sales@fs.com for more details.

Source: http://www.fiber-optic-tutorial.com/how-to-connect-cisco-cisco-nexus-9396px-to-40g-network.html

Migrating to 40/100G With OM3/OM4 Fiber

To meet the continuously increased requirements, data center 40/100G migration is underway. The infrastructure of data centers for the 40G/100G should meet the requirements like high speed, reliability, manageability and flexibility. To meet these requirements, product solutions and the infrastructure topology including cabling must be considered in unison. Cable deployment in the data center plays an important part. The cable used in data center must be selected to provide support for data rate applications not only of today but also the future. Today, two types of multimode fiber—OM3 and OM4 fibers (usually with aqua color)—have gradually become the media choice of data center during 40/100G migration. This article illustrates OM3/OM4 multimode fibers in 40/100G migration in details.

Data Center and Multimode Fibers

Multimode fiber is being widely used in data centers. You might ask why not single-mode fiber? The answer is cost. As is known to all, the price of single-mode fiber is generally more expensive than multimode fiber. In addition multimode fibers provide a significant value proposition when compared to single-mode fiber, as multimode fiber utilizes low cost 850 nm transceivers for serial and parallel transmission. If you had all money you wanted and you’d just run single-mode fiber which has all the bandwidth you need, then you can go plenty of distance. However, this perfect situation would cost a lot of money. Thus, most data center would choose multimode fiber. OM1, OM2, OM3 and OM4 are the most popular multimode fiber. But OM3 and OM4 are gradually taking place of OM1 and OM2 in data centers.

OM stands for optical multimode. OM3 and OM4 are both laser-optimized multimode fibers with 50/125 core, which are designed for use with 850nm VCSELS (vertical-cavity surface-emitting laser) and are developed to accommodate faster networks such as 10, 40 and 100 Gbps. Compared with OM1 (62.5/125 core) and OM2 (50/125 core), OM3 and OM4 can transport data at higher rate and longer distance. The following statistics (850 nm Ethernet Distance) shows the main differences between these four types multimode fibers, which can explain why OM3 and OM4 is more popular in data center now in some extent.

850 nm Ethernet Distance

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

 

Why Use OM3 and OM4 in 40/100G Migration

The Institute of Electrical and Electronics Engineers (IEEE) 802.3ba 40/100G Ethernet Standard was ratified in June 2010. The standard provides specific guidance for 40/100G transmission with multimode and single-mode fibers. OM3 and OM4 are the only multimode fibers included in the standard. The reason why OM3 and OM4 are applied in 40/100G migration is that they can meet the requirements for the migration cabling performance.

Bandwidth, total connector insertion loss and transmission distance are two three main factors should be considered when evaluation the performance needed for cabling infrastructure to meet the requirements for 40/100G. These factors can impact the cabling infrastructure’s ability to meet the standard’s distance of at least 100 meters over OM3 fiber and 150 meters over OM4 fiber. The following explains why OM3/OM4 are the chosen ones for 40/100G migration.

Get Higher Bandwidth With OM3/OM4

Bandwidth is the first reason why OM3 and OM4 are used for 40/100G migration. OM3 and OM4 are optimized for 850nm transmission and have a minimum 2000 MHz?km and 4700 MHz?km effective modal bandwidth (EMB). Comparing the OM1 and OM2 with a maximum 500 MHz?km, advantages of OM3 and OM4 are obvious. With a connectivity solution using OM3 and OM4 fibers that have been measured using the minimum Effective Modal Bandwidth calculate technique, the optical infrastructure deployed in the data center will meet the performance criteria set forth by IEEE for bandwidth.

Get Longer Transmission Distance With OM3/OM4

The transmission distance of fiber optic cables will influence the data center cabling. The manageability and flexibility will be increased with fiber optic cables with longer transmission distance. OM3 fiber and OM4 fiber can support longer transmission distance compare with other traditional multimode fibers. Generally OM3 fibers can run 40/100 Gigabit at 100 meters and OM4 fibers can run 40/100 Gigabit at 150 meters. This high data rate and longer distance cannot be achieved by other traditional multimode fiber like OM1 and OM2. Employing OM3 fiber and OM4 in 40/100G migration is required.

Get Lower Insertion Loss With OM3/OM4

Insertion loss has always been an import factor that technically should consider during the data center cabling. This is because the total connector loss within a system channel impacts the ability to operate over the maximum supportable distance for a given data rate. As total connector loss increased, the supportable distance at that data rate decreases. According to the 40/100G standard, OM3 fiber is specified to a 100m distance with a maximum channel loss of 1.9dB, which includes a 1.5dB total connector loss budget. And OM4 fiber is specified to a 150m distance with a maximum channel loss of 1.5 dB, including a total connector loss budget of 1.0 dB. With low-loss OM3 and OM4 fiber, maximum flexibility can be achieved with the ability to introduce multiple connector mating into the connectivity link and longer supportable transmission distance can be reached.

OM3 or OM4?

Choosing OM3/OM4 is a wise and required choice for data center 40/100G migration. However, OM3 and OM4, which is better? Numerous factors can affect the choice. However, the applications and the total costs are always the main factors to consider to figure out whether OM3 or OM4 is needed.

First, the connectors and the termination of the connectors for OM3 and OM4 fibers are the same. OM3 is fully compatible with OM4. The difference is just in the construction of fiber cable, which makes OM4 cable has better attenuation and can operate higher bandwidth at a longer distance than OM3. Thus, the cost for OM4 fiber is higher than OM3. As 90 percent of all data centers have their runs under 100 meters, choosing OM3 comes down to a costing issue. However, looking in the future, as the demand increases, the cost will come down. Thus, OM4 might be the most viable product at some point soon.

No matter choosing OM3 or OM4, the migration is underway. With good performance like high data rate, long transmission distance and lower inserting loss, OM3/OM4 fiber is a must in data center migration to 40/100G.

Source: http://www.fiber-optic-tutorial.com/migrating-to-40100g-with-om3om4-fiber.html