Active DAC vs. Passive DAC(Direct Attach Cable)

As one kind of optical transceiver assembly, a direct attach cable (DAC) is used to connect one mobility access switch with another when forming a stack, which can be either passive or active. Since the passive DAC cable contains no active components, it provides a direct electrical connection between corresponding cable ends. This process can also be done by an active DAC cable that is considered active because there are optics and/or electronics embedded within the connectors. To put it simply. Active DAC vs. passive DAC: An Active DAC contains electronics for signal conditioning. While A Passive DAC does not contain electronics for signal conditioning. Then Why choose one implementation over the other? Just keep reading!

DAC

Active vs. Passive DAC

If a DAC contains the signal conditioning circuitry, it is an “Active DAC”. If the DAC does not contain this circuitry, it is a “Passive DAC”. For a passive DAC to work, the host networking equipment must support the signal processing functions. When an SFP+ is inserted, networking gear compatible with passive DAC reads the module type, and the signal conditioning is activated only when a passive DAC is detected. In all other cases, standard “machine level” signals are sent across the SFP+ edge connector.

More than 80% of all SFP+ equipped switches on the market today support passive DACs. The remaining less than 20% perform no signal conditioning and, therefore, must be equipped with substantially more expensive Active DAC if copper interconnection is desired. However, these switches, since they do not contain the signal conditioning on each SFP+ port, are considerably less expensive.

Active vs. Passive DAC: Which to Choose

The decision regarding which way to go, a switch supporting Passive DAC or one requiring Active DACs, depends on several factors including:

Fiber Connectivity—If the application of a given switch is expected to utilize primarily/exclusively fiber SFP+ transceivers, the added cost of a switch that supports Passive DAC may not be warranted. On the other hand, if SFP+ ports are expected to be equipped primarily with DAC, the higher cost of the switch will be quickly recovered by the savings using low-cost Passive DAC versus higher priced Active DAC.

Length of DAC Spans—If the primary application of the use of DAC is limited to about 7 meters or less (e.g. within a rack or between adjacent racks), a solution supporting Passive DAC is indicated. However, if most of the DACs deployed with the switch are greater than 7 meters in length (e.g., ToR to EoR), Active DAC would be required regardless of the switch, so a low-priced Active-DAC-only switch may be the right choice. In fact, if a switch supporting signal conditioning detects an active DAC inserted, it will not use its internal signal conditioning circuitry but will leave that function to the active DAC itself.

FS.COM 10G DAC Solutions

FS.COM provides a full range of DACs, both passive and active, for all major and many minor brands of switches. The following is a sample of the popular 10G DACs offered by FS.COM:

Part Number Brand Active/Passive
SFP-H10GB-CU1M Cisco Passive
SFP-H10GB-ACU5M Cisco Active
Force10 CBL-10GSFP-DAC-2M Dell Passive
EX-SFP-10GE-DAC-10MA Juniper Active
CAB-SFP-SFP-1.5M Arista Passive
10G-SFPP-TWX-0701 Brocade Active
JD096C HPE Passive

Conclusion

Besides the 10G DACs mentioned above, FS.COM offers a variety of high speed interconnect DAC assemblies including 10G SFP+ Cables, 40G QSFP+ Cables, and 120G CXP Cables to satisfy the demands from 10G to 100G interconnection. All of the FS.COM direct attach cables can meet the ever growing need to cost-effectively deliver more bandwidth, and can be customized to meet different requirements. For more information, please visit fs.com or contact over e-mail service@fs.com.

Introduction to HP ProCurve Mini-GBICs and SFPs

About HP ProCurve

HP ProCurve was the name of the networking division of Hewlett-Packard from 1998 to 2010 and associated with the products that it sold. The name of the division was changed to HP Networking (also called HP ProCurve Networking) in September 2010 after HP bought 3Com Corporation. As the then-ProCurve division began to offer LAN switches, Core, Datacenter, Distribution, Edge, Web managed and Unmanaged Switches. The ProCurve was also used with Network Management, Routing and Security products. HP ProCurve transceivers as the part of its networking accessories that are applied to their corresponding switches or routers. Today, we will introduce some knowledge of the HP ProCurve Mini-GBICs and SFPs.

FS.COM Optical Transceiver Solutions for HP ProCurve
ProCurve Gigabit-SX-LC Mini-GBIC (Product No. J4858A/J4858B/J4858C)

A small form-factor pluggable (SFP) Gigabit SX transceiver with 1LC port that provides a full-duplex Gigabit solution up to 550 m on multimode fiber.

HPE J4858A Compatible 1000BASE-SX SFP

FS.COM Solution:

  • NEW HP J4858A X121 Compatible 1000BASE-SX SFP 850nm 550m Transceiver Module
  • NEW HP J4858B X121 Compatible 1000BASE-SX SFP 850nm 550m Transceiver Module
  • NEW HP J4858C X121 Compatible 1000BASE-SX SFP 850nm 550m Transceiver Module
ProCurve Gigabit-LX-LC Mini-GBIC (Product No. J4859A/J4859B/J4859C)

An SFP format gigabit transceiver with LC connectors using LX technology.

HPE J4859A Compatible 1000BASE-LX SFP

FS.COM Solution:

  • NEW HP J4859A Compatible 1000BASE-LX SFP 1310nm 10km Transceiver Module
  • NEW HP J4859B Compatible 1000BASE-LX SFP 1310nm 10km Transceiver Module
  • NEW HP J4859C Compatible 1000BASE-LX SFP 1310nm 10km Transceiver Module
Things You Should Know About HP ProCurve Mini-GBICs and SFPs

For the above products, there usually are many questions about them. The following information will let you know more about them.

Supported Platform

According to HP ProCurve Networking Mini-GBIC Support Matrix, we can easily find out which Mini-GBICs and SFPs are supported on which ProCurve Systems. General rules are:

  • Please use only genuine or high-quality 100% compatible ProCurve Mini-GBICs and SFPs on ProCurve System.
  • Newer ProCurve products require revision “B” or later Mini-GBICs and SFPs (product number ends with the letter “B” or later, for example J4858B, J4859C).

Some-Compatible-Systems-1024x378

About the Version A, B, C

HP ProCurve Mini-GBICs and SFPs have three versions, but you may not find A and B anymore in HP’s official website. In fact, the version A, B and C are the development of HP ProCurve Mini-GBIC and SFP. Though there is no big difference between these three versions, some improvement will be added in the newest version, and the supported platforms adjustment. The “revision C” Mini-GBICs (eg. J4858C, J4859C, J4860C) are supported in all ProCurve products that support Mini-GBICs. In addition, “revision B” and “revision C” mini-GBICs can be used together in any ProCurve switch that supports mini-GBICs. Actually, as the transitional products, HP stops offering the version A and version B. But version C are not supported on some old switches, thus, some users have still used the version A or version B. FS.COM can support the 100% compatible HP ProCurve Mini-GBICs and SFPs at version A, B and C, such as J4858A/B/C, J4859A/B/C, J4860A/B/C.

Mini-GBICs and SFPs hot-swappable

All ProCurve Mini-GBICs and SFPs are hot-swappable (they can be installed and removed while the switch is powered on). However, the network cable should be disconnected before removing the Mini-GBIC or SFP from the switch.

Best practice tip: After inserting a transceiver into a ProCurve switch, the Mode LED will come on for two seconds while the transceiver is initialized. Do not remove the transceiver until the Mode LED has turned off. For the Switch 2600 and 2800 Series: After inserting a transceiver into a 2600 or 2800 switch, the “M” LED will come on to indicate that the mini-GBIC slot is active. Wait at least two seconds after the “M” LED comes on if you need to remove the transceiver.

About FS.COM

FS.COM is a professional manufacturer and supplier of optical networking solutions. We can supply 100% compatible fiber optic transceiver modules of many brands, like HP, Cisco, Dell, D-link etc. with an incredible discount. About HP, you can find a full product line of HP transceivers with a good price and enjoy same-day shipping. In addition, according to your requirements, we welcome any inquiry for customized fiber optic transceiver. FS.COM’s aim is offering the best quality products and perfect solutions, saving customers’ time and money.

What Kind of Switches and Patch Cables Should I Choose for SFP Transceiver?

Gigabit Ethernet has supplanted Fast Ethernet in wired local networks and becomes ubiquitous throughout the world, serving as one of the most prevalent enterprise communication standard. The Gigabit Ethernet standard supports a maximum data rate of 1 gigabit per second (Gbps)(1000 Mbps), 10 times faster than Fast Ethernet, yet is compatible with existing Ethernet. To link your switches and routers to a Gigabit Ethernet network, you need a Gigabit Ethernet transceiver as a transmission medium. This article intends to introduce the most commonly used one—SFP transceivers.

sfp

What Is SFP Transceiver?

SFP, short for small form-factor pluggable is a compact, hot-pluggable transceiver used for both telecommunication and data communications applications. SFP transceiver can be regarded as the upgrade version of GBIC module. Unlike GBIC with SC fiber optic interface, SFP module is with LC interface and the main body size of SFP is only about half of GBIC so that it can save more space. SFP interfaces a network device mother board (for a router, switch, media converter or similar devices) to a fiber optic or copper networking cable. It is designed to support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards.

Types & Applications of SFP transceivers

SFP transceivers are available with various transmitter and receiver types, which facilitates users to select the appropriate optical transceiver for different optical reach and optical fiber type (single-mode fiber or multimode fiber) required by different link. SFP transceiver modules can be divided into several different categories:

Types Transmission Medium Wavelength Distance
1000BASE-T SFP Twisted-pair cabling / 100 m
1000BASE-SX SFP Multimode fiber 770-860 nm OM1-275 m/OM2-550 m
1000BASE-LX/LH SFP SMF & MMF 1270-1355 nm MMF-550 m/SMF-5 km
1000BASE-ZX SFP Single mode fiber 1550 nm 70 km
1000BASE-EX SFP Single mode fiber 1310 nm 40 km
1000BASE-BX10 SFP Single mode fiber 1480-1500 nm downstream, 1260-1,360 nm upstream 10 km
CWDM and DWDM SFP Single optical fiber various wavelengths various maximum distances

SFP transceivers are found in Ethernet switches, routers, firewalls and network interface cards. Storage interface cards, also called HBAs or Fibre Channel storage switches, also make use of these modules. Because of their low cost, low profile, and ability to provide a connection to different types of optical fiber, SFP transceiver provides such equipment with enhanced flexibility.

FS.COM Compatible SFP Transceivers for Popular Switches

FS.COM offers a full range of SFP transceivers compatible with major brands, such as Cisco, Juniper, Arista, Brocade, HPE, etc. All of these cost-effective compatible SFPs have been strictly tested to make sure 100% compatibility. The table below listed a small part of compatible SFPs supported on major branded switches.

Brand Switch Series Model Port Description
Cisco Catalyst 6500 Series WS-SUP720-3BXL 2 SFP Port
VS-S720-10G-3C 4 SFP Port
WS-X6724-SFP 24 SFP Port
Nexus 9000 Series N9K-C9396PX 48 SFP Port
IE3010 Series IE-3010-24TC 2 SFP Port
ASR 9000 Series Router A9K-MPA-20X1GE 20 SFP Port
Juniper EX 4200 Series EX4200-24T 2 SFP Port
EX4200-48T 4 SFP Port
EX4200-24T-DC 2 SFP Port
MX480 Router MX480 Router 4 SFP Port
SRX Series SRX210 1 SFP Port (Option)
QFX 5100 QFX5100-48S 48 SFP Port
Arista 7500 Series DCS-7504 48 SFP Port (Option)
DCS-7508 48 SFP Port (Option)
7050SX Series 7050SX-64 48 SFP Port
7100 Series DCS-7124S 24 SFP Port
Brocade VDX 6720 BR-VDX6720-16-R 16 SFP Port
BR-VDX6720-24-F 24 SFP Port
BR-VDX6720-40-F 40 SFP Port
SX Series SX-424F 24 SFP Port
SX-FI12GM-4-PREM 12 SFP Port
Brocade BI-RX-8 NI-MLX-1Gx20-SFP 20 SFP Port
HPE ProCurve 5400zl Series J8697A 2 SFP Port
J9548A 144 SFP Port
FlexFabric 5800 Series JC101B 4 SFP Port
JG225B 6 SFP Port
5400R zl2 Series J9584A 24 SFP Port
StorageWorks edge 2/12 348406-B21 12 SFP Port

FS.COM Patch Cables for SFP Transceivers

FS.COM offers comprehensive fiber patch cables for common and special types of SFPs, including singlemode & multimode, simplex & duplex, UPC & APC, lengths from 1 meter to 30 meters in large stocks. We also provides Cat 5e patch cables for 10/100/1000BASE-T SFPs.

Fiber Mode Connector Jacket
9/125 SMF LC Duplex PVC/LSZH/OFNP
9/125 SMF LC Simplex PVC/LSZH
9/125 SMF SC Simplex PVC/LSZH
50/125 OM2 LC Duplex PVC/LSZH
62.5/125 OM1 LC Duplex PVC
Cat5e Patch Cables Max Distance Data Rate
Unshielded (UTP) 100m 1000Mbps
Shielded (FTP) 100m 1000Mbps

Summary

This article offers switch and fiber patch cabling solution for SFP transceivers. Besides the major brands mentioned above, we also provide SFP transceivers compatible with other brands, such as Dell, Extreme, H3C, Huawei, Intel, IBM, Netgear, Ciena, D-Link, Avago, and so on. As to special requirements, please contact Sales@fs.com for suggestion.

What is an Optical Transceiver?

Definition

Optical transceiver, also known as fiber optic transciever, is a device that uses fiber optic technology rather than conventional electrical wire to send and receive data. It is made of optoelectronic devices, functional circuits and optical interfaces. Optoelectronic devices include two parts: transmitter and receiver. To put it simple, a fiber optic transceiver serves as a photoelectric converter. The transmitter converts an electrical signal into a light signal, and then the receiver converts the light signal into an electrical signal after transmission through the optical fiber. Fiber optics is a rapidly growing field and can communicate complex information faster than conventional methods of transferring data.

optical module

How Does It Work?

The optical transceiver module is composed of both a transmitter and a receiver that are arranged in parallel so that they can operate independently. In the fiber optics, the transmission of data is in the form of light, because the transceiver has electronic components to encode or decode data into light pulses and then sends them to the other end as electrical signals in order to be utilized by an electronic device. The transmitter converts an electrical signal into an optical signal, which is connected with a connector and transmitted through a fiber optic cable. The light entering from the end of the cable is connected to a receiver where a semiconductor detector converts the light back into an electrical signal.

transmitter-and-receiver

Package

According to the package, there are six common types of fiber optic transceivers popular in the market, namely GBIC, XFP, SFP, SFP+, XENPAK, and X2.

1. GBIC (Gigabit Interface Converter). GBIC is designed for hot-plug. It is an interchangeable product meeting international standards. GBIC optical modules are used widely before SFP package.

2. SFP (Small Form-factor Pluggable). SFP is an upgraded version of the early GBIC module. It features smaller volume and higher integration than GBIC fiber module. It is currently the most popular optical module in the market.

3. SFP+. SFP+ optical module has been upgraded based on SFP with a higher transmission rate, usually up to 8.5G or 10G.

4. XFP. XFP transceiver (10 Gigabit Small Form Factor Pluggable) is a hot-swappable, independent of the communication protocol optical transceiver. XFP is usually used for 10Gbps SONET/SDH, Fibre Channel, Gigabit Ethernet and other applications, but also for CWDM DWDM link.

5. XENPAK. XENPAK is a multisource agreement (MSA), instigated by Agilent Technologies and Agere Systems. It’s a 10 Gigabit Ethernet optical transceiver which is independent of transceiver circuits and optical components. It can be plugged into a router or switch. But now XENPAK has been replaced by more compact devices providing the same functionality.

6. X2. X2 transceiver is a 10Gbps modular fiber optic interface intended for use in routers, switches and optical transport platforms. X2 modules are smaller and consume less power than XENPAK modules, but larger and consume more energy than XFP and SFP+ transceivers.

differen types of transceivers

Optical Transceivers are Used in a Variety of Applications

One of the most important attributes of optical transceivers is their ability to be compatible in a variety of communication applications. Most manufacturers choose them because they fit in a small footprint, and they are reliable. Besides, compatibility is one of the most common considerations in fiber optic transceivers. Take SFP fiber optic transceiver as an example, a SFP fiber optic transceiver on a network device (such as a switch, router, media converter, or similar devices) provides the device with a modular interface so that the user can easily adapt to various fiber optic or copper networking standards. They are designed to support SONET (Synchronous Optical Networking), Gigabit Ethernet, Fibre Channel, and other communications standards.

Conclusion

This article briefly tells about what an optical transceiver is, comprising its definition, its working mode, different types according to package and its usage. I hope it may be helpful to you!

SFP28 and QSFP28 Transceivers Cabling Solutions

Due to the increasing number of connected devices in use and their need for fast cloud-based data processing, the Ethernet interconnect standard widely used in data centers is evolving to move data more quickly and efficiently, which has driven the development of a 25Gbps version of Ethernet. Before 25G Ethernet was proposed, the next speed upgrade for data centers was expected to be 40G Ethernet (using four lanes of 10G) with a path to 100G defined as using 10 lanes of 10G as shown in the following table. However, the 25G Ethernet standard can provide a path to 100G and achieve higher total bandwidth than 40G. This article will discuss the different connection methods between 25G SFP28 and 100G QSFP28 transceivers.

total bandwidth of differnet Ethernet network

Note: 100G QSFP28 can be interfaced with 12-fiber MTP connector or duplex LC connector. In this post, the QSFP28 modules we mentioned all have MTP interface.

Direct Connectivity Solution

According to standard, since QSFP28 is 100G interface, SFP28 is 25G interface, four SFP28 transceivers must be needed to connect to one QSFP28 transceiver to achieve 25G to 100G transmission. In this scenario, an 8-fiber MTP-LC harness will be required to direct connect a QSFP28 port to the four corresponding SFP28 ports. This harness cable has four duplex LC connectors and the fibers will be paired in a specific way, assuring the proper polarity is maintained. Keep in mind that this direct connectivity method only recommended for short distance within a give row or in the same rack or cabinet.

Direct Connectivity Solution

Interconnect Solutions

Solution 1: This interconnect solution shown in the image below allows for patching on both ends of the optical network. The patching on the QSFP28 end is accomplished by using Type-A non-pinned MTP to non-pinned MTP jumper, which connects to the trunk cable, while the patching on the SFP28 end is accomplished using MTP modular cassette and duplex LC patch cable.

interconnect solution 1

Solution 2: In this scenario, a Type-B non-pinned MTP to duplex LC breakout cassette will be used to breakout an 8-fiber QSFP28 transceiver into a 2-fiber SFP28 patching field. This solution does reduce the amount of system attenuation by removing a MTP connector pair, however, it would be that the port breakout module has a limited tail length. Besides, this cabling solution only works best when the active equipment being connected is within the same row.

interconnect solution 2

Solution 3: This interconnect solution allows for an easy upgrade path moving from 2-fiber to 8-fiber connectivity. To connect to the SFP28s ports use the 8-fiber harness as shown in the following diagram, and an 12-fiber MTP trunk cable would be used from the adapter panel for the QSFP28 connectivity, thus allowing a mix and match upgrade patch without having to change out the patch panels. The SFP28 transceiver ports need to be located in the same chassis, which creates less flexibility.

interconnect solution 3

All the products introduced in the above solutions including SFP28 transceivers, QSFP28 transceivers, MTP breakout cassette, MTP adapter panel, MTP trunk cable, etc. can be purchased in FS.COM. We provide free and the same day shipping to the US now.