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Several 100G DWDM Solutions for Arista 7500E Series

Several 100G DWDM Solutions for Arista 7500E Series

To keep up with the global demand for higher bandwidth, Arista has designated 7500E series switch to address 100G long-hual dense wavelength division multiplexing (DWDM) connectivity. Arista 100G interconnect solution combines Layer 2/Layer 3 switching, wire-speed encryption and coherent DWDM into a high-density line card for the Arista 7500E data centers. Along with the introduction of Arista 7500E series switches, this article will illustrate several 100G DWDM solutions for distance up to 80 km, 150 km and 3000 km as well.

Arista 7500E Series Switch & Line Card

Arista 7500E series is the second generation of 7500 series switch that delivers scalable and deterministic network performance for mission critical data centers, enterprise and HPC environments. Available in a compact 7RU (4-slot) or 11RU (8-slot), Arista 7500E offers over 30Tbps of total capacity for 1,152 ports of 10GbE, 288 ports of 40GbE and support for 96-port 100GbE with a broad choice of interface types that support flexible combinations of 10G, 40G and 100G modes on a single port.

The 7504 and 7508 are the two types of Arista 7500E series switches. The 7508 systems support 8 linecards, dual supervisor modules and 6 fabric modules to provide a full 30Tbps of capacity. The smaller 7504 systems share a common architecture with the 7508 with the primary difference being support for 4 linecards and 15Tbps of forwarding capacity. The most unique feature of this switch is that it can connect with 10G SFP+, 40G QSFP+, 100G QSFP28 and CFP2 modules.

arista-7500E-switch

Arista 7500E series line card for addressing 1/10G, 40G and 100G with full support for industry standard connections and comprehensive layer 2 and 3 features for flexible deployment choice. The line card delivers error-free performance up to 3000 km of fiber and consumes less than 140W per 100Gbps. Similar to any other Arista platform, the DWDM line card utilizes the single binary image of Arista’s extensible operating system (EOS). Line cards with CFP2 and QSFP support standard 100G for both single and multimode fiber for distance up to 40 km.

Why Need 100G DWDM Solution?

100G optical transceivers provide the most straightforward method to connect 100G traffic over long-hual applications. 100G optics like CFP and QSFP28 offer cost-optimized solutions for connecting 100G switches together in a rack or data center. Nevertheless, the small and cost-effective QSFP28 100G optics now can only handle connections over distances of less than 10 km. For example, QSFP28 LR4 is compliant with 100GBASE-LR4 standard that operates over duplex LC cables for a link length of 10 km.

As to the CFP form factors, coherent CFP modules is designed to support metro and long-hual DWDM applications. CFP 100GbASE-ER4 can support up to 40 km. However, owing to its large size and high power consumption, CFP transceivers are less popular on the market. If you want to use CFP optics for 100G deployment, keep in mind, CFP modules are too large to fit in the Ethernet switches and will significantly reduce port counts and increase power usage, making 100G switches poor performance in cost-effectiveness. Therefore, customers who want to upgrade 100G network can only cover a distance of 10 km, which is obviously insufficient for geographically separated data centers or metro infrastructures. Figure 2 shows the basics of DWDM system.

DWDM-System

To realize 100G long-distance transmission, Arista 100G DWDM solution combines DWDM optics with a fully passive Mux/Demux system that can handle up to 3,000 km. Arista 100G DWDM solution is a 6 x 100G Coherent DWDM line card for the 7500E series with integrated wire-speed encryption and analog coherent CFP2 optical interfaces. Several use cases for the Arista 7500E Series DWDM card in multi-site data center networks exist. The following sections identify three use cases for Arista 7500E DWDM solutions.

Use Cases for Arista 7500E DWDM Solutions
  • Use Case 1—Less Than 80KM Dark Fiber Connection

For a typical metro link that is less than 80 km, Arista 7500E Series DWDM line cards can directly terminate a dark fiber connection providing a point-to-point connection between two locations.

DWDM solution for 80 km

Just as figure 3 shows, Arista DWDM solution is ideal for metro applications transmitting up to 9.6Tbps traffic without the need for any additional amplification.

  • Use Case 2—Greater Than 80 km But Less Than 150 km

When extending the distance beyond 80 km, there is a need to amplify the signal to offset heavy signal loss that occurred in the light signal when passing through fiber cables, patch panels and other optical devices. Under this circumstance, EDFA’s or Erbium Doped Fiber Attenuators are employed to give the aggregated wave a boost.

100G DWDM solution about 100 km

By using EDFAs (seen in Figure 4) to the transmit side of each end of the dark fiber link, the signal can be boosted to achieve distances of up to 150 km. Exact distances will be dependent on the number of patches, fiber splices and quality of the fiber.

  • Use Case 3—Greater Than 150 km But Less Than 3,000 km

Arista 7500E DWDM solutions can also cover the distance of greater than 150 km but less than 3000 km. Employing further EDFAs at a spacing of approximately 80 km along the fiber route allows the length of a connection to be extended to over 3,000 km. As shown below, EDFAs are used on both paths to boost the signal.

DWDM solution for 3000 km

Supported Optics for Arista 7500E Series

All Arista 10G SFP+ transceivers, with the exception of LRM, are supported on the Arista 7500E SFP+ ports.

Interface Type SFP+ ports
10GBASE-CR 0.5m-5m
10GBASE-AOC 3m-30m
10GBASE-SRL 100m (OM3) / 150m (OM4)
SFP-10G-SR 300m (OM3) /400m (OM4)
SFP-10G-LRL 1km
SFP-10G-LR 10km
SFP-10G-ER 40km
10GBASE-DWDM 80km
SFP-10G-ZR100 100km
100Mb TX, 1GbE SX/LX/TX Yes

The 40G QSFP+ transceivers and cables allow for 4x10G mode support with the use of fiber breakout cables, MTP to LC cassettes, or QSFP to SFP+ cables. See the below table for details on the latest supported 40G transceivers.

Interface Type QSFP+ ports
40GBASE-CR4 0.5m-5m
40GBASE-AOC 3m-100m
QSFP-40G-UNIV 150m (OM3) / 150m (OM4), 500m (SM)
QSFP-40G-SRBD 100m (OM3) /150m (OM4)
QSFP-40G-SR4 100m (OM3) / 150m (OM4)
QSFP-40G-XSR4 300m (OM3) / 400m (OM4)
QSFP-40G-PLRL4 1km (1km 4x10G LR/LRL)
QSFP-40G-PLR4 10km (10km 4x10G LR/LRL)
QSFP-40G-LRL4 1km
QSFP-40G-LR4 10km
QSFP-40G-ER4 40km

100G QSFP28 and CFP2 Optics

Interface Type 100G CFP2 Ports 100G QSFP Ports
100GBASE-XSR10 300m OM3 / 400m OM4 Parallel MMF
100GBASE-SR4 100m OM3 / 150m OM4 Parallel MMF
100GBASE-LR4 10km SM Duplex 10km SM Duplex
100GBASE-LRL4 2km SM Duplex
100GBASE-ER4 40km SM Duplex
100GBASE-CWDM4 2km SM duplex
100GBASE-PSM4 500m SM Parallel
100GBASE-AOC 3m to 30m
100GBASE-CR4 1m to 3m
Conclusion

Arista 7500E DWDM solution works in conjunction with passive Optical Mux/Demux devices and in-line amplifiers to support additional bandwidth and extended reaches. Arista 7500E DWDM solution can directly reach up to 80 km without requiring in-line amplification, which is ideal for metro applications. With an Optical Signal to Noise ratio (OSNR) of 11.6dB, it can be used effectively for point to point long-haul applications up to 3,000kms with in-line amplifiers and multiplexers.

Comparison of 40GbE Connectivity Options

Comparison of 40GbE Connectivity Options

High speed and wide bandwidth demands drive data centers to consolidate into more complex systems. The speed of data center now is increasing to 40 Gbps and eventually to 100 Gbps. Thus, new optical technologies and cabling infrastructure are required. In this post, I will introduce some commonly used fiber optic cabling connectivity options for 40Gbps infrastructure.

Pluggable Optical Modules: 40G QSFP+ Transceivers
As we know, fiber optic transceiver is an electronic device that receives an electrical signal, converts it into a light signal, and launches the signal into a fiber. It also receives the light signal, from another transceiver, and converts it into an electrical signal. It is the key component in fiber optic transmission. The basic interface of 40G pluggable optical modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor, such as Cisco QSFP-40G-LR4 and QSFP-40G-SR4.

QSFP-plus-module

40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver support with a link length up to 10 kilometers over 1310 nm single mode fiber, LC Connector. It is most commonly deployed between data-center or IXP sites with single mode fiber.

40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support the transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP.

In addition, for single-mode fiber transmission, there are 40GBASE-LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km. For multimode fiber transmission, QSFP+ extended SR4 transceivers are developed which is designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.

Passive & Active Direct Attach Copper Cables
The QSFP+ passive or active direct attach copper cables are designed with twinax copper cable and terminated with QSFP+ connectors. The main difference between passive QSFP+ DAC and active QSFP+ DAC is that the passive one is without the active component. They provide short distance (same shelf) inexpensive connectivity at up to 40Gbps rates and operate 4 independent 10G channels using the QSFP connector footprint. Each of the four channels can operate at multi-rate speeds Gigabit to 10Gbps.

QSFP+ DAC

Active Optical Cable (AOC) Assemblies
Active optical cable, namely AOC brings a more flexible cabling than direct attach copper cables with the advantages of lighter weigth, longer transmission distance and higher performance for anti-EMI. Now, 40G AOC assemblies are popular with users.

QSFP+ AOC

After introducing the basic options of 40G cabling connectivity, we take a conclusion for the above content in the following tables:

40G-cabling-options

 

In addition, don’t forget there are some typical cabling components you will require when building 40G cabling, such as MTP trunk cables, MTP cassettes, LC to MTP jumpers and so on.

MTP Assemblies

Fiberstore offers a comprehensive solution for 40G fiber optic cabling connectivity. What’s more, products such as 40GBASE-LR4 and 40GBASE-SR4 QSFP+ modules are in stock and can shipped in 12hrs. For more information, please visit www.fs.com.

What Are The Differences Between SFP, SFP+, XFP, QSFP/QSFP+, CFP and QSFP28?

What Are The Differences Between SFP, SFP+, XFP, QSFP/QSFP+, CFP and QSFP28?

Recently, we can see some products information about fiber optic transceivers, such SFP, SFP+, XFP, QSFP and QSFP+ on facebook. Have you ever wondered what are they respectively for and what’s the difference between them? Today, we are going to talk something about them in this paper.

SFP
SFP, small form-factor pluggable for short, is a compact, hot-pluggable transceiver module used for both telecommunication and data communications applications. SFPtransceiver can be regarded as the upgrade version of GBIC module. Unlike GBIC with SC fiber optic interface, SFP is with LC interface and the main body size of SFP is only about half of GBIC, which makes the SFP space saving. SFP interfaces a network device mother board (for a router, switch, media converter or similar devices) to a fiber optic or copper networking cable. Meanwhile, SFP is a popular industry format supported by many network component vendors. SFP transceiver modules are designed to support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards.

SFP

SFP+
SFP+ is an enhanced version of the SFP that supports data rates up to 10 Gbit/s. SFP+ supports 8 Gbit/s Fibre Channel, 10-gigabit Ethernet and Optical Transport Network standard OTU2. It is a popular industry format supported by many network component vendors. Initial standard applications focused on 8G Fibre Channel, 10G Ethernet and 10G Fibre Channel, where the electrical interface to the host board is a standardized serial interface called SFI. The applications have expanded to include SONET OC-192, SDH STM-64, OTN G.709, CPRI wireless, 16G Fibre Channel, and the emerging 32G Fibre Channel application.

SFP+

XFP
XFP has appeared before the SFP+. It is also a standardized form factor for serial 10 Gb/s fiber optic transceivers. It is protocol-independent and fully compliant to the following standards: 10G Ethernet, 10G Fibre Channel, SONET OC-192, SDH STM-64 and OTN G.709, supporting bit rate from 9.95G through 11.3G. XFP transceivers are used in datacom and telecom optical links and offer a smaller footprint and lower power consumption than other 10 Gb/s transponders. The electrical interface to the host board is a standardized serial 10 Gb/s interface called XFI.

xfp

QSFP/QSFP+
QSFP is short for quad (4-channel) small form-factor pluggable. It is a compact, hot-pluggable transceiver also used for data communications applications. QSFP+ evolved as the standard to support 10Gb/s data rates per SFF-8436. Compared with QSFP+, QSFP products support Quarter Small Form-factor Pluggable with the different data rate so that there is no change in the product solution. Nowadays, QSFP+ gradually replace QSFP and is widely used by people as it can provide higher bandwidth.

QSFP+

CFP
CFP, namely C form-factor pluggable, is a multi-source agreement to produce a common form-factor for the transmission of high-speed digital signals. The c stands for the Latin letter C used to express the number 100 (centum), since the standard was primarily developed for 100 Gigabit Ethernet systems. It can support a wide range of 40 and 100 Gb/s applications such as 40G and 100G Ethernet, OC-768/STM-256, OTU3, and OTU4.

CFP

QSFP28

The 100G QSFP28 transceiver module is a high-density, high-speed product designed for 100Gbps applications. It has the same form factor as the QSFP+ transceievrs. QSFP28 100G optics offers four channels of high-speed differential signals with data rates ranging from 25 Gbps up to potentially 40 Gbps, and finally meet 100 Gbps Ethernet (4×25 Gbps) and 100 Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements. QSFP28 transceiver recently is typically available in several standards—100GBASE-SR4, 100GBASE-LR4, 100GbASE-PSM4 and 100GBASE-CWDM4. QSFP28-100G-SR4 operates over multimode fiber for a distance of 100 m. While 100GBASE-LR4 QSFP28 supports a much longer distance of 10 km. Compared with CFP form factors, QSFP28 optics are more popular on the 100G optics market.

QSFP-100G-CWDM4-S

Differences of These Fiber Optic Transceivers
Through the above definitions of each type of fiber optic transceiver module, you may have a further understanding of them. Now, we are comparing these transeiver one by one.

  • SFP vs SFP+ (SFP+ vs SFP): Simple to understand, SFP+ is an update vision of SFP. SFP usually support 1.25Gbit/s to 4.25 Gbit/s while SFP+ supports data rates up to 10 Gbit/s. SFP and SFP+ have the same size and appearance, but in different standard which SFP is based on IEEE802.3 and SFF-8472.
  • SFP+ vs XFP (XFP vs SFP+): In comparison to earlier XFP modules, SFP+ modules leave more circuitry to be implemented on the host board instead of inside the module. The size of SFP+ is smaller than XFP, thus it moves some functions to motherboard, including signal modulation function, MAC, CDR and EDC. XFP is based on the standard of XFP MSA while SFP+ is compliance with the protocol of IEEE 802.3ae, SFF-8431, SFF-8432.
  • SFP+ vs QSFP+: QSFP+ has four-channel SFP+ interfaces which can transfer rates up to 40Gbps. And of course they have different standards.
  • CFP vs QSFP+: QSFP+ (Quad Small Form-Factor Pluggable Plus) modules offer customers a wide variety of high-density 40 Gigabit Ethernet. The CFP is a hot-pluggable transceiver module form factor that supports a wide range of 40Gb/s and 100Gb/s applications such as 40G and 100G Ethernet.

Related articleHOW TO CHOOSE QSFP28 OPTICS FOR 100GBE DEPLOYMENT

A Cost-effective Way to Increase Aggregate Data Rates Beyond 10 Gbps

A Cost-effective Way to Increase Aggregate Data Rates Beyond 10 Gbps

Fiberstore QSFPRecent interest has been shown in further increasing the transceiver port density for optical datacom applications, particularly blade servers, as well as finding a cost effective way to increase aggregate data rates beyond 10 Gbps. One approach is the Quad Small Form Factor Pluggable (QSFP, or QSFP+) Multi-Source Agreement (MSA), originally announced in March 2006 and finalized in December 2006 following a period of public comment on the proposed specifications. The QSFP MSA is currently endorsed by over 20 companies (e.g, Fiberstore).

As illustrated in the figure below, QSFP defines an integrated, hot pluggable, 4-channel optical transceiver, designed to replace four standard SFP+ modules in a space only 30% larger than a single SFP+. The resulting port density is three times higher than conventional SFP+ designs; various stacked and ganged configurations are possible to achieve increased port density, and presumably lower cost per port (a minimum of 21 mm center-to-center spacing is allowed for adjacent QSFP Transceivers). The transceiver is a so-called z-axis pluggable module, meaning that the 38 contact electrical connector can be inserted parallel to the host circuit board without requiring additional operations such as screwing the transceiver package to the host card.

Dimensions of QSFP

MPO Interface for QSFP

QSFP accommodates a standard MPO connector, though as shown in figure above only 8 of the 12 available fibers are used to carry signals. Exposed portions of the optical connector or card bezel are color coded following common industry practice (beige for 850nm/multimode, blue for 1300nm/single-mode, white for 1550nm/single-mode). The MSA defines a mechanical form factor with latching mechanism similar to that used by XFI, host board electrical receptacle, and a cage to house the transceiver when it is plugged onto a host card. Digital diagnostics are provided to monitor link performance; the diagnostic interface includes the ability to set link distance parameters that identify the capabilities of the transceiver, including an option for copper QSFP implementations. QSFP uses a single 3.3 V nominal power supply, with a maximum power dissipation under 3.5 W.

Various types of vendor-specific heat sinks can be attached or clipped onto the transceiver. Data rate options ranging from 100 Mbps to 10 Gbps per channel are defined (with an available rate select pin on the electrical interface) to support protocols, including Ethernet, Fibre Channel, InfiniBand, and SONET/SDH. In particular, with a potential data rate of 10-Gbps/channel, this transceiver may provide a cost-effective implementation of 40 Gbps links. The inherent 4 + 4 channel architecture of QSFP lends itself to increase distances supported by multilane serial I/O electrical interconnects such as PCI Express (PCIe) and InfiniBand.

Cisco Leads 100G Ethernet Switch Market

Cisco Leads 100G Ethernet Switch Market

In first quarter of 2013, the worldwide Ethernet switch market was $ 4.7 billion, decreased by 8% compared with 2012Q4, but an increase of 1%. 40G is the only port shipment growth products, an increase of 2%, which was mainly due to 40G fixed switches (such as 16xQSFP+) and chassis-based switches 40G line cards. Cisco is the early leader in 100G Ethernet switch port.

Due to the influence of seasonal factors, in first quarter of 2013, the Ethernet switch sales fell, but the past three quarters, the overall is still increased, taking into account the continued weakness in Europe and the U.S. federal government expense decreased , this is a positive signal.

In first quarter of 2013, port shipments fell 4%. 10G, which is generally considered as a star product, the chain fell highest.

40G is the only port shipment growth products, an increase of 2%, which was mainly due to 40G fixed switches (such as 16xQSFP +) and chassis-based switches 40G line cards.

Almost all of the Ethernet switch equipment manufacturers on a quarter-on-quarter drop.

Cisco is the early leader in 100G Ethernet switch port.