2019年6月30日星期日

the armored fiber optic patch 10G cables are small diameter

Armored fiber optic patch 10G cables uses stainless steel armor inside the jacket, which helps make it resistant of high tension and pressure. It retains all the features of normal patch cord, but much more stronger. When individuals use such armored 10G cables, they don’t need to worry the rodent animals such as the rats may bite the cables and make them broken. It may resist the load of an adult person, and it is difficult to break when bent or dragged. The interior armor can safeguard the entire cable from rodent. With stainless steel tube within the outer jacket to safeguard the central unit from the cable, the armored fiber optic patch cables are simple to use in harsh invironment. Although armored QSFP+ 10G cables are strong, they’re actually as flexible as standard fiber optic patch cords and could be bend randomly without having to be broken.
 
Installation procedure and maintenance is also easy. They’re ideal option for people who is seeking fiber optic patch cords with addtional durability and protection in addition to light weight. They retain the feature of all common types fiber optic patch cables, they are flexible to deploy in FTTH projects inside the buildings, normally the armored fiber optic patch 10G cables are small diameter and with PVC jacket, suit for indoor only use, outdoor usage fiber optic patch cables can also be found, they are with heavy PE jacket. They can be used directly in full duplex various harsh environment without additional protection.they can save space, reduce construction cost, making the constant maintenance more conveniently. Furthermore, the stainless steel tube prevents optic fiber from damage, which improves security and stability of the system.

Singlemode Fibre optic cables features a micron glass core

During some Fibre optic cables installations, there is a need to provide extra protection for the cable due to the installation environment. That environment may be underground or in buildings with congested pathways. Installing an armored fiber-optic cable in these scenarios would provide extra protection for the Fibre optic cables and added reliability for the network, lessening the risk of downtime and cable damage due to rodents, construction work, weight of other cables and other factors.In the daily connection work, a connector housing should be used when plugging or unplugging a fiber. 
 
A protective cap should be used to cover the unplugged fiber connectors. In the process of the CX4 / SFF-8470 Fibre optic cables, the end face of the connector should never be touched and also the clean area of a tissue of swab should not be touched or reused.
 
 
Multimode fiber has a large diameter fiber core. Due to its relatively large size, multiple channels of light can be transmitted, allowing multiple bandwidths and signals to be transmitted simultaneously. Multimode works great for most fiber applications. It works especially well in alarm systems, audio/video systems and production, desktops and laptops, and display density applications systems. Multimode Fibre optic cables has a large-diameter core that is much larger than the wavelength of light transmitted, and therefore has multiple pathways of light-several wavelengths of light are used in the fiber core. 
 
Multimode fiber optic cable can be used for most general fiber applications. Multimode fiber optic cable is used for bringing fiber to the desktop, for adding segments to your existing network, or in smaller applications such as alarm systems. It comes with two different core sizes which are 50 micron or 62.5 micron.

which also use the SFP+ Cables cabling

This has caused the Fibre Channel community to create a Fibre Channel over Ethernet (FCoE) specification that helps to preserve the native protocol and its installed base. The InfiniBand community has similarly created its RoCE, or RDMA over Converged Ethernet, standard specification. RDMA is Remote Direct Memory Access, a low-latency and low-power technology used with InfiniBand architecture. So now these four interface, 10GBaseCR, 10GFCoE, 10GFC and 10GRoCE are implemented using the same SFP+ single-lane passive copper cabling. 
 
10G SFP+ usage has grown dramatically because active copper and active optical SFP+ Cables have enabled increased market segments and longer-length applications like digital signage and AV systemsBesides Fibre Channel, other storage interfaces like NAS, iSCSI, iSATA and ATAoE are tunneled over Ethernet 10GBaseCR. These other storage interfaces are also tunneled over Ethernet 10GBaseT using Category 6a and Category 7a cabling. 
 
There are open and closed Consortia de facto standards using these multi-protocols on so-called collapsed architectural fabrics like the Unified Computing System, which also use the SFP+ Cables cabling.Besides UCS, there are several other de facto standard unified style networks, which also use the SFP+ but with different encryption in memory mapping of the embedded plug EPROMs. 
 
One wonders if all of these IO interfaces will expand and use the newly developing 25/26/28Gbit/sec QSFP++ module and cabling system, which is being standardized through the SFF-8661/2/3 specification.

2019年6月27日星期四

Things You Should Know About 1000BASE-LX/LH SFP

1000BASE-LX/LH SFP, one of the commonly used fiber optic transceivers, is now widely used in optical transmission systems. With the development of 40/100G Ethernet, even 400G Ethernet, this kind of transceiver module is nothing new to the module users. However, few people can deliver a clear answer to the question of what “1000BASE-LX/LH” infers. Well, if you know what it means, congratulations! you are the one of the few. You can skip today’s contents or share your experience to us in the comment. Actually, this post is a simple reference source for the beginners in this field or those who are lack of knowledge with fiber optic transceiver but have a strong interest in it.
 
To begin with, I’d like to make a brief introduction of 1000BASE-LX/LH SFP transceiver. This kind of SFP is similar with the other SFPs in basic working principle and size. But it is compatible with the IEEE 802.3z 1000BASE-LX standard, operating on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. In addition, when used over legacy multimode fiber type, the transmitter should be coupled through a mode conditioning patch cable.
 
As we know, an optical transceiver module is generally either made for single mode (long distance) or multimode (short distance). But 1000BASE-LX/LH SFP can be used for both singlemode and multimode. In fact, the Ethernet standard defines this optical interface specification as 1000BASE-LX10. However, many vendors as a proprietary extension called either 1000BASE-LX/LH or 1000BASE-LH before it was standardized. Thus, we often see 1000BASE-LX/LH rather than 1000BASE-LX10.
 
In a word, 1000BASE-LX/LH SFP has two identities. It is single mode by design, but when it gets together with its friend “mode conditioning patch cable”, it can also be used for multimode application. This patch cable inserts a single to multi splice on the transmit path, to “fill” the multimode fiber with light. It is more expensive than normal patch cables, but is necessary if using these on multimode fiber. At present, 1000BASE-LX/LH SFP is the only one kind of fiber optic transceivers which can be used for both singlemode and multimode applications. And these applications are depending on what fiber you use.

Making the Case for 10 Gigabit Ethernet

Several factors make 10GbE implementations a compelling option, including interoperability, cost efficiency, low power consumption, communication quality, and hardware availability. Each of these factors merits careful consideration.
 
Interoperability Leveraging Existing Technology
 
During infrastructure upgrades, 10GbE and the TCP/IP protocol are designed to interoperate seamlessly with GbE links, enabling a relatively easy and nondisruptive transition to 10GbE. Two different types of 10GbE connectors are expected to facilitate these links, including 10GBase-T copper and the 10GbE small form-factor pluggable+ (SFP+) interconnect. SFP+ supports different physical port types such as 10GBASE Twinax copper and various types of fiber connections.
 
By helping ensure that the 10GbE components can cooperatively communicate with GbE devices, switch vendors can deliver interoperability between GbE and 10GbE. Data transitioning from 10GbE to GbE links potentially requires additional buffering on the 10GbE switch to temporarily store the data while it is being transmitted to a low-speed device. In addition, support can be provided for the expected Ethernet standard pause frames (IEEE 802.3x) and priority flow control standards that are part of the enhanced Ethernet standards.
 
Cost Efficiency Resulting from Fewer Connections
 
Over time, as 10GbE becomes commonplace, one 10GbE port is expected to be more cost-efficient than multiple GbE ports and Fibre Channel ports. Current GbE storage normally requires multiple ports to provide acceptable storage bandwidth between hosts and arrays. Based on industry best practices for redundancy, a minimum of two connections are used to provide a failover path between host and storage. Additional bandwidth may be required by the application—for example, the performance of sequential data applications such as data warehouses is typically gated by bandwidth. Another best practice is to isolate storage traffic on the SAN from client/server traffic on the LAN, which requires a separate LAN port. Dedicated management ports are often required as well. Just two 10GbE connections (for minimal redundancy) in conjunction with enhanced Ethernet standards such as DCB can handle these requirements while still upholding the best practices just described.
 
Low Power Consumption with SFP+ optics
 
Since the 10GBase-T standard was adopted in 2007 for twisted-pair copper cabling, efforts have been underway to help reduce 10GBase-T power consumption—with a goal of reaching power levels per port that are equivalent to the current 1GBase-T standard. First-generation 10GBase-T adapters have higher wattage demands than their short-reach optical counterparts. Currently, prototype second-generation 10GBase-T implementations are designed to bring wattage demand per port down to reasonable levels.
 
10GbE SFP+, which today is an early implementation choice for network and storage vendors such as Dell, Cisco, HP, etc. that has very low wattage requirements per port, and SFP+ direct attach copper cable can provide a power-efficient, cost-effective 10 m cabling reach between rack-mounted servers and a top-of-rack switch.
 
In SFP+ direct attach connections, the module is built into the cables (SFP+ cable). This effort, along with the reduction in the number of separate connections required to manage multiple networks, should help significantly reduce the power requirements of the network.
 
Communication Quality with Compliant Standards
 
The Data Center Bridging (DCB) standard is expected to encompass several IEEE 802.1 standards to help ensure communication quality for 10GbE and iSCSI deployments. Priority flow control (802.1Qbb), a link-level flow-control mechanism, is designed to ensure zero loss under congestion in DCB networks. Another standard, 802.1Qau, is intended to provide end-to-end congestion management.
 
Hardware Availability to Mix GbE and 10GbE
 
Hardware is available today for mixing GbE and 10GbE. For example, the Dell PowerConnect M8024 blade I/O switch modules can configure ports to run at GbE or 10GbE speeds and provide several options for physical connection types; SFP+ optics use in GbE and 10GbE Ethernet links, such as the Finisar FTLX8571D3BCV 1G/10G Dual-Rate SFP+ optical transceiver over multimode fiber and FTLX1471D3BCV 1G/10G Dual-Rate SFP+ optical transceiver link length up to 10km over singlemode fiber. When used in conjunction with an external 10GbE switch, such as the planned PowerConnect 8024F SFP+ switch, and legacy GbE switches, such as the PowerConnect 6200 series, this hardware is expected to offer several options for configuring iSCSI storage solutions that utilize mixed Ethernet speeds.

2019年6月26日星期三

SFP Transceiver Signals and Types

The SFP transceiver holds a Printed track Board that partners with the SFP electronic connector in the service configuration.
 
A “base transceiver station” (BTS) is a bit of outfits that eases wireless information exchange amid exploiter out fits (UE) and a network. UEs are implements like protable telephones (handsets), Wireless native loop telephones, computers with wireless Internet connectivity.
 
The network may be that of whatever of the wireless information exchange applications of tools and methods like GSM, CDMA, wireless native circle, WIFI, WiMAX either different ample zone network (WAN) technics.
 
BTS is as well referenced to like the broadcast center facility (RBS), point B(in 3G Networks) either, plainly, the center facility (BS). For conversation of the 3GPP Long TERM Evolution normal the shortening EnodeB for developed point B is extensively applied.
 
Though the expression BTS may be appropriate to whatever of the wireless information exchange norms, it is normally related with portable information exchange applications of tools and methods like GSM and CDMA. In this heed, a BTS forms piece of the center facility self-contained system within larger system (BSS) elaborations for configuration administration. It might as well have outfits for encrypting and decrypting information exchanges, range filtrating implements (band go filters), etcetera. Antenas might as well be deemed like parts of BTS in common feel as they some dissimilar turnaround and dissimilar areas of the cell (in the situation of sectorised center stations). A BTS is managed by a progenitor center facility regulator by way of the center facility command purpose (BCF). The BCF is executed like a separate component either even integrated in a TRX in firm center stations. The BCF delivers a transactions and upkeep (OM) link to the network administration configuration (NMS), and organizes operative states of every one TRX, as well like code managing and alert gathering. The fundamental construction and purposes of the BTS stays the similar notwithstanding of the wireless technologies.
 
RF module – Transceiver modules
An RF Transceiver component includes either a sender and recipient. The track is characteristically developed aimed at Half-duplex working, though Full twofold components are accessible, characteristically at a developed outlay expected to the appended difficulty.
 
Small form-factor pluggable transceiver – Types
SFP transmitters and receivers are accessible with a diversity of sender recipient kinds, permitting consumers to choose the suitable transceiver for every one link to supply the needed ocular get to over the accessible ocular fiber sort (e.g. Multi-mode fiber either single-mode fiber). Optical SFP components are normally accessible in some dissimilar categories:
 
For multi-mode fiber, with black either ecru removal lever
 
SX – 850nm, for a greatest of 550m at 1.25Gbit/s (Gigabit Ethernet) either 150m at 4.25Gbit/s (Fibre Channel). Related product: 1000BASE SX SFP.
 
1000BASE-SX SFP
For single-mode fiber, with azure removal lever
 
LX – 1310nm, for spaces up to 10km (e.g. Cisco GLC-LX-SM-RGD).
EX – 1310nm, for spaces up to 40km.
ZX – 1550nm, for spaces up to 80km.
EZX – 1550nm, for spaces up to 120km.
BX – 1490nm/1310nm, Single Fiber Bi-Directional Gigabit SFP Transceivers, matched as “BS-U” and “BS-D” for Uplink and Downlink correspondingly, as well for spaces up to 10km. Variations of bidirectional SFPs are as well produced that employ 1550nm in one management.
1550nm 40km (XD), 80km (ZX), 120km (EX either EZX)
SFSW – Single Fiber Single Wavelength transmitters and receivers, for bi-directional SFPs are a sole fiber. Coupled with CWDM, those duple the flow thickness of fiber ties.
CWDM and DWDM transmitters and receivers at different wavelengths attaining different greatest distances.

Things You Should Know About 1000BASE-LX/LH SFP

1000BASE-LX/LH SFP, one of the commonly used fiber optic transceivers, is now widely used in optical transmission systems. With the development of 40/100G Ethernet, even 400G Ethernet, this kind of transceiver module is nothing new to the module users. However, few people can deliver a clear answer to the question of what “1000BASE-LX/LH” infers. Well, if you know what it means, congratulations! you are the one of the few. You can skip today’s contents or share your experience to us in the comment. Actually, this post is a simple reference source for the beginners in this field or those who are lack of knowledge with fiber optic transceiver but have a strong interest in it.
 
To begin with, I’d like to make a brief introduction of 1000BASE-LX/LH SFP transceiver. This kind of SFP is similar with the other SFPs in basic working principle and size. But it is compatible with the IEEE 802.3z 1000BASE-LX standard, operating on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. In addition, when used over legacy multimode fiber type, the transmitter should be coupled through a mode conditioning patch cable.
 
As we know, an optical transceiver module is generally either made for single mode (long distance) or multimode (short distance). But 1000BASE-LX/LH SFP can be used for both singlemode and multimode. In fact, the Ethernet standard defines this optical interface specification as 1000BASE-LX10. However, many vendors as a proprietary extension called either 1000BASE-LX/LH or 1000BASE-LH before it was standardized. Thus, we often see 1000BASE-LX/LH rather than 1000BASE-LX10.
 
In a word, 1000BASE-LX/LH SFP has two identities. It is single mode by design, but when it gets together with its friend “mode conditioning patch cable”, it can also be used for multimode application. This patch cable inserts a single to multi splice on the transmit path, to “fill” the multimode fiber with light. It is more expensive than normal patch cables, but is necessary if using these on multimode fiber. At present, 1000BASE-LX/LH SFP is the only one kind of fiber optic transceivers which can be used for both singlemode and multimode applications. And these applications are depending on what fiber you use.

2019年6月25日星期二

How Many Types of Fiber Optic Patch Cords Do You Know?

Fiber optic patch cords are also known as “fiber optic jumper” or “fiber optic patch cables”. It’s commonly used in fiber optic network. According to the transmission medium, it can be divided into two types: single-mode fiber optic patch cords and multi-mode fiber optic patch cords. According to optical connector, it can be classified into many types, such as FC, LC, MU, SC, ST, etc.
 
This article will introduce the categories classified by optical connector to help you know more about them and choose what kind of fiber optic patch cords you need. An optical fiber connector enables quicker connection and disconnection than splicing by terminating the end of an optical fiber. Here are some popular fiber optic patch cords terminated with FC/LC/MU/SC/ST connectors on both ends.
 
FC Fiber Optic Patch Cords
FC fiber optic patch cords, for example, FC-FC multi-mode fiber patch cable, are with FC fiber optic connectors, which is a metal threaded screw type connection. FC connectors’ floating ferrule provides good mechanical isolation. FC connectors need to be mated more carefully than the push-pull types due to the need to align the key, and due to the risk of scratching the fiber end face while inserting the ferrule into the jack.
 
LC is short from “Lucent Connector”. LC fiber patch cord connector is a push and latch structure, with plastic housing and accurate 1.25mm ceramic ferrule. LC type is a popular kind of small form fiber optic patch cord which reduces the space and it is widely used for densely installation, such as LC-LC Fiber Patch leads.
 
MU Fiber Optic Patch Cords
MU fiber optic patch cord is also the invention of NTT in Japan. MU is a small size fiber optic patch cord with plastic housing and a push pull structure. MU fiber optic connector is similar size of LC. It’s designed for high-density connections and provides more than double the packaging density of the SC connector.
 
SC Fiber Optic Patch Cords
SC fiber optic patch cord was invented by the Japanese company NTT. It’s one of the most widely used fiber optic patch cords because it has advantages of low cost, simplicity and durability. SC fiber optic patch cords are with a locking tab on the cable termination. It is a push and pull type fiber optic connector with excellent packing density.
 
ST Fiber Optic Patch Cords
ST fiber optic patch cords are with straight tip type terminations. There is only simplex ST fiber optic patch cords and no duplex ones. ST fiber optic connectors, widely used for multi-mode networks, are usually with a metal housing, although there is plastic housing.

Why Is Single-mode Fiber So Attractive?

Since the invention of optical fibers in the early 1970s, the use of and demand for optical fiber today are quite numerous. With the explosion of information traffic due to the Internet, electronic commerce, computer networks, multimedia, voice, data, and video, the need for large amount of signal transmission is paramount. Fiber optics has proven to be the best solution. Single-mode fiber is one of optical fibers which is designed for the transmission of a single ray or mode of light as a carrier and is used for long-distance signal transmission.
 
A typical single-mode fiber has four parts: the core, cladding, buffer and jacket. In the center, it’s called the core where the light is “guided” down in the fiber. The core is surrounded by an optical material called the “cladding” that traps the light in the core using an optical technique called “total internal reflection”. The core and cladding are usually made of ultra-pure glass. The fiber is coated with a protective plastic covering called the “primary buffer coating” that protects it from moisture and other damage. More protection is provided by the cable which has the fibers and strength members inside an outer covering called a “jacket”.
 
Single-mode fiber has characteristics of low dispersion, high frequency and high bandwidth. First, the high dispersion rate will make the signal worse during its transmission over long distances. When the light travels through the core, the core doesn’t retain all of the light. As a result, the dispersion will be caused when some of the light travels along the fiber cladding. Single-mode fiber could erase the dispersion. Second, the frequency at which the fiber optic signal will be transmitted can influence the signal transmission distance. The higher the frequency, the greater distance the system will be able to support. Single-mode systems have 1300 and 1550 nanometers. Third, bandwidth of fiber is described in MHz per kilometer. Typical fiber bandwidth of single-mode fiber has an inherently higher bandwidth and can reach thousands of MHz per km.
 
Due to the special favorable characteristics of single-mode fiber, it could transmit data with high speed over long distances. And it’s usually used for connections over large areas, such as college campuses and cable television networks. So that’s why single-mode fiber is attractive especially for long distance signal transmission.

Are You Familiar with EDFA?

Signals travel through fibers over large distances with attenuation. Then the optical amplifiers are needed in the CWDM (corse wavelength divsion multiplexing) and DWDM (dense wavelength divsion multiplexing). Optical amplifiers are devices that can amplify optical signals directly without the need to convert them to electrical signals. EDFA (erbium doped fibre amplifier) is the most common optical amplifiers.
 
Introduction of EDFA
EDFA is doped with element erbium and with the core of a silica fiber. It is one of DWDM equipment that amplifies optical fiber signals as signals will be attenuated when the transmission distance is over hundreds kilometers. The term “doping” refers to the process of using chemical elements to facilitate results through the manipulation of electrons. It is employed in the telecommunications field and in various types of research fields.
 
Principles of EDFA
In general, EDFA works on the principle of stimulating the emission of photons. Pump lasers, known as pumping bands, insert dopants into the silica fiber, resulting in a gain, or amplification. EDFA amplification occuring as the pump laser excites the erbium ions, which then reach a higher energy level. The excited ions make transition to the ground state either by CWDM, DWDMequipmentamplified spontaneous emission or stimulated emission. The amplified spontaneous emission is a major source of noise in the system. And the stimulated emission could amplify signals by generating photons. With EDFA, an erbium-doped optical fiber at the core is pumped with light from laser diodes. This type of setup in telecom    systems can help with fiber communications.
 
Advantages of EDFA
EDFA has many advantages. First, it can provide in-line amplification of a signal without the need for E-O and O-E conversions. Second, it can directly and simutaneously amplify a wide wavelength band (>80nm) in the 1550nm region with a relatively flat gain. Third, it provides high power transfer efficiency from pump to signal power. At last, EDFA has low noise, which is suitable for long haul applications.
 
Although EDFA has so many advantages, it has disadvantages as well. For example, EDFA is usually limited to no more than 10 spans covering a maximum distance of approximately 800 kilometers (km). When the distance is longer, an intermediate line repeater to retime and reshape the signal and filter accumulated noise from various light dispersion forms in the optical fiber would be required. So EDFA still needs to be improved.

2019年6月24日星期一

SFP+ Cable Interconnect Assemblies Overview

SFP+ passive copper cable assemblies were developed specifically as a costeffective and lower-power alternative to optical fiber cables for short reach links in high-speed interconnect applications such as high performance computing (HPC), data center networking and network storage markets. The assemblies support data transfer rates up to 10 Gb/s per lane, meeting or exceeding current Industry Standard Specifications. These SFP+ fully-shielded assemblies combine twin-axial shielded cable with robust die cast connector interfaces for enhanced support of high frequency data rates.
 
SFP+ passive copper cable assemblies use twin-axial (twinax) shielded cable, which means that the signals travel over parallel pairs of conductors that have foil shields over each pair with a drain wire interstitial to the conductors. The cable contains 2 pairs, one for transmit (Tx) and one for receive (Rx) and each shielded pair is surrounded by an overall shield.
 
Twinax cable has all of the noise cancelling characteristics of twisted-pair cable with the added benefits of homogeneous geometry, which means that the cable’s 100 ohm impedance is much better controlled resulting in less signal loss.
 
Cross-section of SFP+ cable
These assemblies are called passive copper cables because there isn’t any signal conditioning circuitry (e.g. crosstalk or echo cancellation) contained within the SFP+ connector. Sometimes these assemblies are referred to as DAC or SFP+ Direct Attached cables or Cu cables. Inside the SFP+ MSA footprint optical cables can be used that require optical tranceivers or Active Optical Cables (AOC) that contain the transceiver as part of the cable.
 
There are four wire gauges to support our SFP+ passive copper cable assemblies: 30, 28, 26 and 24 AWG. These gauge offerings are based on the attenuation limits within the governing standards; longer cables require larger gauge copper wire.
 
SFP+ connectors contain EEPROMs within the connector’s diecast metal backshell. An EEPROM is an “Electrically Erasable Programmable Read-Only Memory” chip that is programmed at the factory with specific information about the cable assembly. This information is used by the network equipment that the cable is plugged into to get information that is used for signal transmission as well as information about the cable assembly such as vendor, serial number, part number, etc.
 
Applications and Compatibility
 
The initial interface option for 10 Gigabit Ethernet (10GbE) switches and servers were SFP+ ports because the 10GBASE-T standard and products were still being developed. As a result, there are many existing 10GbE switches and servers on the market that support SFP+ cabling. The SFP+ ports allow SFP+ direct attach (DAC) passive copper cable assemblies or SFP+ optical fiber modules to be used within the same port. The choices between SFP+ passive copper or active optical fiber are based on reach or the distance between the ports that are being connected as well as user preference. The passive SFP+ cable has a maximum reach of 5 meters which allows for Top of Rack (ToR) configurations and may also support Middle of Row (MoR) deployments as explained below.
 
The SFP+ DAC performance advantages over 10GBASE-T include lower latency and slightly lower power.
 
SFP+ interfaces take approximately the same space on a switch front panel as the RJ45 connector and, with SFP+ interfaces, switches can be built with 32 or 48 ports of 10 GbE in a single rack-unit height.
 
Cisco passive Twinax 5m
Some equipment vendors discourage the use of 3rd party cable assemblies by issuing a warning message if a non-vendor approved cable is plugged into a port. Most vendors, however, will provide a “work around”. Some errors are simple to clear just by acknowledging brand messaging. Fiberstore’s SFP+ direct attached passive copper cables have been tested by the University of New Hampshire’s Interoperability Lab (UNH IOL) and passed their 10Gigabit Ethernet interoperability testing with several vendors’ devices including: Cisco, Dell, Arista and Brocade.

What Is Main Difference Between Single Mode SFP and Multi Mode SFP?

SFP transceivers are commonly used and necessary in our daily life. And there are two kinds: single mode SFP and multi-mode SFP. However, maybe most people don’t know these two SFP transceivers are different. The following are the differences between single mode SFP and multi-mode SFP.
 
Diameter of the Core
Single mode SFP has a small diametral core that allows only one mode of light to propagate. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and making the signal travel faster.
 
Compared with single mode SFP, multi-mode SFP has a larger diametral core that allows multiple modes of light to propagate. Thus when the light passes through the core, the number of light reflections increases, more data could pass through in a given time.
 
Transmission Distance
Single mode SFP are affected by waveguide dispersion caused by the light going down the fiber being wider than the core of the fiber. This allows more control of the path of the photons, but gets more influences from micro bends, twists, and stress on the fiber. So it’s often applied in long distance, higher bandwidth runs by Telcos, CATV companies, and Colleges and Universities.
 
Whereas multi-mode SFP are affected by Modal Dispersion, caused because the light rays follow different paths through the fiber and arrive at different times on the other end. Due to the high dispersion and attenuation rate with this type of fiber, the signal will become worse during its transmission over long distances. So multi-mode SFP could be typically used for short distance, data and audio/video applications in LANs. RF broadband signals, such as what cable companies commonly use, cannot be transmitted over multi-mode fiber.
 
Cost
Single mode SFP costs more than multi-mode SFP. Why does this happen? Because single mode SFP and multi-mode SFP use a different type of light emitting unit. Single mode SFP have fine laser i.e 1310nm or 1550nm. But multi-mode SFP having LED or lower wavelength type light emitting unit. Multi-mode couplers & lasers are a lot cheaper to manufacturer. Single-mode couplers & lasers are tuned & built to a much higher standard and cost a lot more to produce. So single mode SFP is always more expensive than multi-mode SFP.
 
The main purpose of showing these differences is for you to know SFP transceivers better and choose a suitable one. And the two transceivers are identified by colors on the outer jacket. The single mode SFP is yellow or blue, while the multi-mode SFP is orange or aqua.

An Irresistible Trend- 100 Gigabit Ethernet

In 2006, the IEEE 802.3 working group formed the Higher Speed Study Group (HSSG) and found that the Ethernet ecosystem needed something faster than 10 Gigabit Ethernet. Because the growth in bandwidth for network aggregation applications overpasses the capacities of networks employing link aggregation with 10 Gigabit Ethernet. HSSG is the first to propose that 100 gigabit per second for network aggregation applications. In January 2008, 100 Gb/s Task Force were formed. In June 2010, the 100GbE standards were approved. 100 Gigabit Ethernet (100GbE) means the computer networks transmitting data at rates of 100 gigabits per second.
 
There are two main advantages of 100 Gigabit Ethernet. And they are as following:
Fast speed: Compared with current 10 GbE protocol, 100 Gigabit Ethernet protocol is faster. The technology adheres to the principal Ethernet protocols and interfaces, while significantly boosting speeds and reducing network latency in the process. So for large users, 100 Gigabit Ethernet with heavy bandwidth and low latency is the best choice.
 
Low cost: Carriers and enterprises have to use multiple 10 Gbps connections to satisfy their aggregated bandwidth requirements because there are no alternatives to 10 Gbps. Each new 10 Gbps bandwidth step comes with additional switch and/or computer interfaces which are expensive. For example, the costs for 10x10G fiber cabling are more than the 1x100G cost. In one word, multiple 10 Gigabit Ethernet channels cost more than 100 Gigabit Ethernet network with just one channel.
 
As 100 Gigabit Ethernet comes into our daily life, 100G transceivers have been specifically designed to meet the needs of high speed. What kind of transceivers is suitable? CFP (C form-factor pluggable) transceiver supports the ultra-high bandwidth requirements of data communications and telecommunication networks that form the backbone of the internet. It’s compatible to 100 Gigabit Ethernet. Now there are CFP optical transceiver, CFP2 optical transceiver and CFP4 optical transceiver. From the diagram, the transceivers are smaller and smaller but with more optimization.
 
Today people are moving to the cloud in order to keep information in case it will be lost from one’s local memory storage on a computing device. Thus it increases the bandwidth demand. Most IT leaders believe that this causes significant network overload. Though 10 Gigabit Ethernet and 40 Gigabit Ethernet are common now, it’s said that 100 Gigabit Ethernet will make up over 50% of data center optical 

2019年6月23日星期日

Copper SFP Transceiver for 1000BASE Applications

In the past, because of low cost and compatibility with existing LANs, 100Mb/s Ethernet was very popular. As people’s increasing demands for faster delivery of information, high bandwidth Ethernet LAN is evolving. 1000BASE (1 Gbps Gigabit Ethernet) came around and brought Ethernet technology to a new stage. Gigabit Ethernet, as the new networking techology was a viable solution for increased bandwidth requirements. Early implementation of the technology will be in high-speed backbones and specialized workgroups. The initial standards of 1000BASE were created and maintained by the 802.3z working group of the IEEE LAN-MAN Standards Committee in June 1998.
 
Now that 1000Mb/s Ethernet has been applied generally, the corresponding equipment like the cable and transceiver are needed to make the network the most effective.
 
Before 2000, SFP optical transceiver module combines transmit and receive functions in a compact, low power, low cost package format. Now it’s widely applied in Fibre Channel, Gigabit Ethernet (GbE), and SONET/SDH and supports data rates between 125 Mb/s and 4 Gb/s. Later some manufacturers make SFP ports with copper transceivers. The copper small form factor pluggable (SFP) transceiver can maintain both configuration flexibility and high port utilization with low cost for optical networks. Due to these advantages, the need for copper SFP transceivers increases obviously.
 
Configuration Flexibility with High Port-level
When there is no copper transceiver, users who want to support Ethernet traffic over both copper and fiber should offer two different line cards dedicated to one media or the other or, alternatively, hybrid cards with a fixed number of copper ports and optical cages. But this way is not very efficient because the available ports for each type of media rarely matched the network’s constantly evolving topologies.
 
In today’s network environments, systems must deal with the ongoing convergence of data, voice, and video traffic as well as topologies that mix Internet Protocol (IP) with legacy PDH traffic and integrate specialized requirements such as Fibre Channel or ATM. As GbE switches, routers, and multi-service provisioning platforms (MSPPs), for example, must provide port-level flexibility for handling both fiber and copper interfaces, thus copper SFP transceiver becomes the best way to optimize port-level flexibility.
 
Cisco copper SFP and an optical SFP provide exactly the same physical and electrical interface for any port on the line card. This just needs a single line card design that can handle the entire spectrum of copper and fiber connections. The port utilization copper SFP transceiver can more efficiently to accommodate the changing network requirements.
 
Low Cost
 
The traditional dedicated line card approach increases inventory costs because it has low level of field reconfiguration. Copper SFP transceiver and a common line card design for all ports clearly reduce the inventory costs as well as complete the copper to fiber reconfiguration.
 
All in all, copper SFP transceiver has the advantages such as increased port density, improved system utilization, and low overall costs. Copper SFP transceiver offers users a level of flexibility that did not exist before. So Copper SFP transceiver will still gain its popularity.

Why Is CWDM so Popular?

WDM (wavelength division multiplexing) technology transmitting multiple signals on a single optical fiber by using different wavelengths to carry each signal has been used since 1980s. In the middle of 1990s, dense wavelength division multiplexing (DWDM) enabled carriers to extend the capacity of the SONET/SDH rings in the network core, without installing new fiber. As the development of data service, MAN has become a hot topic of network construction. However, DWDM system brings telecom operators very high costs in MAN construction. So the other kind of WDM technology, CWDM (coarse wavelength division multiplexing) emerged.
 
CWDM has fewer channels than DWDM. The energy from the lasers in a CWDM system is spread out over a larger range of wavelengths than is the energy from the lasers in a DWDM system. CWDM has many advantages like low cost, low power consumption and small volume. As an economical and practical short-distance WDM transmission system, CWDM becomes more and more recognized by people in many MAN applications just as follows.
 
Fiber Exhaust Relief
Fiber exhaust which means lack of network capacity occurs in metropolitan networks. CWDM is a simple and cost-effective way for people to solve fiber exhaust. By using CDWM, new services can be added over an existing single optical fiber. So to increase optical network capacity, people don’t need to replace existing equipment with higher bit rate transmission rate and install new fibers. Otherwise, it will cost too much because installing new fiber is a costly venture in metropolitan areas.
 
Low-cost WDM Deployments
CWDM system with reduced channels is beneficial for carriers in the metro-regional areas. It supports 4-channel configuration. Systems with 4 channels can quadruple the available capacity over an existing network segment, while offering a lower firstin deployment cost than an 8-channel system. For carriers, they should pay attention to two important points including cost and scalability when they need to upgrade to 8 channels systems. So CWDM is a good choice.
 
Central Office to Customer Premise Interconnection
CWDM is a good fit for metro-access applications such as Fiber to the Building (FTTB). An 8-channel CWDM network can deliver 8 independent wavelength services from the Central Office to multiple business offices located in the same building.
 
Due to the low cost, simplicity and scalability features of the latest products such as CWDM modules, CWDM systems is a good choice for overbuilding with Next Generation SONET, DWDM, and proprietary solutions. CWDM is becoming more and more popular among carriers who need to upgrade their networks to accommodate current of future needs while minimizing the use of valuable fiber strands especially in the metropolitan areas.

General Understanding of LC to LC Fiber Optic Cables

Fiber optic patch cords are also known as fiber optic jumpers or fiber optic patch cables. Fiber optic patch cords are designed to provide optical connection for fiber networks within structured cabling systems. It’s a quick and easy method for routing fiber patches in data centers, head-ends, cellular hubs and central offices. It’s composed of two parts: optical connector and fiber optic cable. As to the connector, fiber patch cords could be terminated with LC/SC/ST/FC/MTRJ/MU/SMA connectors on both ends.
 
With the increasing deployment of fiber in the LAN, the need for small form factor fiber optic connectors is becoming urgent. The main reasons are deployment cost and space savings for cabling hardware and equipment interfaces. LC connector is a small form factor connector with half size of SC connector. The connector was invented by Lucent Technologies. Lucent is an American multinational telecommunications equipment company. So LC stands for Lucent Connectors. The connectors are made to support Telecom and Datacom networks.
 
The LC fiber patch cable is with a small form factor connector and suitable for high density applications. It’s compliant with IEC, Telcordia, EIA/TIA. One of the fiber optic patch cords LC series is LC to LC fiber patch cord. LC to LC fiber patch cord includes LC-LC single-mode and LC-LC multi-mode types.
 
LC-LC single-mode has two versions like simplex and duplex. Single-mode simplex fiber cable is single strand and single-mode duplex fiber cable is zipcord cable which is tight-buffered and jacketed. To be easily identified, the color of the cable jacket is often yellow. And the diameter is usually 1.8mm, 2mm or 3mm. The LC-LC single-mode fiber optic cables have the features of good performance and fast delivery. It’s used for long distance transmission.
 
LC-LC multi-mode patch cords are composed of a polymer outer body and inner assembly fitted with a precision alignment mechanism. As single-mode patch cords, this kind has both simplex and duplex versions too. These cables are with typical 50/125 and 62.5/125 optional multi-mode fiber. The cable diameter is 0.9mm, 2mm or 3mm. Due to the thick core size, the signal degradation caused by the refraction occurs. Thus it’s usually used for short distance signal transmission.
 
LC to LC fiber optic cables, as one kind of fiber optic patch cords, have many advantages such as high return loss, low insertion loss and back reflection loss, good durability, high temperature stability, good interchangeability and duplication. Thus they are widely used in Gigabit Ethernet and fiber channel, multimedia, telecommunication, and high speed data transmission throughout the network, etc.

2019年6月20日星期四

Multi-fiber Connectors for High Port Density

As the introduction of multimode optical fibers of the categories OM3 and OM4 are used for implementing 40 GbE and 100 GbE, though the small diameter of the optical fibers poses no problems in laying the lines, the ports suddenly have to accommodate four or even ten times the number of connectors. This large number of connectors can no longer be covered with conventional individual connectors. Thus, some vendors such fiber-mart.com start to provide the incorporated optical connectors with very low loss for high port density. This article talks about MPO connectors and its high performance connector –MPT connector.
 
The MPO connector is short for multi-fiber push on. It’s defined according to IEC 61754-7 and TIA/EIA 604-5 that can accommodate up to 72 fibers in the tiniest of spaces, comparable to an RJ45 connector. MPO connectors are most commonly used for 12 fibers (Figure 1).
 
MPO Connector Benefits
MPO connectors deliver the optical, mechanical and environmental performance that service providers need to expedite the addition of fiber capacity and to support higher data-rate services. Among the numerous operational, financial and competitive benefits of using MPO connectors in the core network are:
 
Optical insertion loss and return loss performance similar to single-fiber connectors
Maximum space savings for high-density fiber environments
Reduced labor costs via fast, easy installation– because one 12-fiber MPO connector replaces 12 single fiber connectors
Compliant with standards, i.e., IEC 61754-7; IEC 61755-3-31, IEC 61753-1
However, the fibers are usually glued into holes within the ferrule body. Fibers glued directly into the body with MPO connectors make reworking later on difficult and put limits on manufacturing accuracy. And there will be some angle errors and radial displacement. So MTP connectors different from the MPO in various ways. e.g. rounded pins and oval shaped compression springs are created to prevent scratches during plug-in and protect the fibers in the transition area from connector to cable.
 
The MTP connector (Figure 2) is a high performance MPO connector with multiple engineered product enhancements to improve optical and mechanical performance. The MTP connectors are compliant with all MPO connector standards including IEC-61754-7.
 
MTP Connector Benefits
The MTP connector has benefits that generic MPO connectors don’t have. And they are as follows:
 
1. The MTP connector housing is removable. So you can rework and re-polish the MT ferrule, change the gender after assembly and scan the ferrule interferometrically after assembly.
2. The MTP connector offers ferrule float to improve mechanical performance. This allows two mated ferrules to maintain physical contact while under an applied load.
3. The MTP connector uses tightly held tolerance stainless steel guide pin tips with an elliptical shape. The elliptical shaped guide pin tips improves guidance and reduces guide hole wear.
4. The MTP connector spring design maximizes ribbon clearance for twelve fiber and multi-fiber ribbon applications to prevent fiber damage.
5. The MTP connector is offered with four standard variations of strain relief boots to meet a wide array of applications.
 
MPO/MTP connectors play an important role in the multi-fiber connection system. The connectors ensure fiber alignment when mating and realize high density interconnection. MPO/MTP connectors save time and reduce the risk of damaging fragile optical connectors.

General Understanding of LC to LC Fiber Optic Cables

Fiber optic patch cords are also known as fiber optic jumpers or fiber optic patch cables. Fiber optic patch cords are designed to provide optical connection for fiber networks within structured cabling systems. It’s a quick and easy method for routing fiber patches in data centers, head-ends, cellular hubs and central offices. It’s composed of two parts: optical connector and fiber optic cable. As to the connector, fiber patch cords could be terminated with LC/SC/ST/FC/MTRJ/MU/SMA connectors on both ends.
 
With the increasing deployment of fiber in the LAN, the need for small form factor fiber optic connectors is becoming urgent. The main reasons are deployment cost and space savings for cabling hardware and equipment interfaces. LC connector is a small form factor connector with half size of SC connector. The connector was invented by Lucent Technologies. Lucent is an American multinational telecommunications equipment company. So LC stands for Lucent Connectors. The connectors are made to support Telecom and Datacom networks.
 
The LC fiber patch cable is with a small form factor connector and suitable for high density applications. It’s compliant with IEC, Telcordia, EIA/TIA. One of the fiber optic patch cords LC series is LC to LC fiber patch cord. LC to LC fiber patch cord includes LC-LC single-mode and LC-LC multi-mode types.
 
LC-LC single-mode has two versions like simplex and duplex. Single-mode simplex fiber cable is single strand and single-mode duplex fiber cable is zipcord cable which is tight-buffered and jacketed. To be easily identified, the color of the cable jacket is often yellow. And the diameter is usually 1.8mm, 2mm or 3mm. The LC-LC single-mode fiber optic cables have the features of good performance and fast delivery. It’s used for long distance transmission.
 
LC-LC multi-mode patch cords are composed of a polymer outer body and inner assembly fitted with a precision alignment mechanism. As single-mode patch cords, this kind has both simplex and duplex versions too. These cables are with typical 50/125 and 62.5/125 optional multi-mode fiber. The cable diameter is 0.9mm, 2mm or 3mm. Due to the thick core size, the signal degradation caused by the refraction occurs. Thus it’s usually used for short distance signal transmission.
 
LC to LC fiber optic cables, as one kind of fiber optic patch cords, have many advantages such as high return loss, low insertion loss and back reflection loss, good durability, high temperature stability, good interchangeability and duplication. Thus they are widely used in Gigabit Ethernet and fiber channel, multimedia, telecommunication, and high speed data transmission throughout the network, etc.

Should We Use Third-Party Compatible SFP Transceiver?

Many customers tend to use third-party compatible Cisco SFP transceivers to save costs on these expensive modules. But there maybe a problem that the Cisco’s new line switches do not support third-party SFPs. When inserting an SFP transceiver into Cisco switches to connect network backbone, you will find it doesn’t match an official Cisco product. Then you will stumble across the following error:
 
%PHY-4-UNSUPPORTED_TRANSCEIVER: Unsupported transceiver found in Gi1/0/0
%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port 65538 has bad crc
 
The Catalyst switch disables the GBIC port. That’s because Cisco Catalyst switches are configured by default not to work with non-Cisco SFPs. When a third-party SFP inserted into the port, the switch immediately recognize it doesn’t match. And it will throw the above error message and disables the port.
 
Except the error, Cisco tends to be very strict about the warranty requirements for the third-party components including SFP transceivers. The details are as following: When Cisco determines that a fault or defect can be traced to the use of third-party transceivers installed by a customer or reseller, then, at Cisco’s discretion, Cisco may withhold support under warranty or a Cisco support program. In the course of providing support for a Cisco networking product Cisco may require that the end user install Cisco transceivers if Cisco determines that removing third-party parts will assist Cisco in diagnosing the cause of a support issue.
 
That means if you use a third-party transceiver and it causes actual damage. Cisco may refuse warranty support. If the transceiver is merely suspected of being at fault, they may refuse support until you install a supported Cisco-branded transceiver.
 
Now you may ask “Are the third-party compatible transceivers safe?”. The answer is yes. Most third-party transceivers are made and assembled in exactly the same plants assembling officially-branded transceivers. In a matter of speaking, an official Cisco transceiver and a third-party transceiver are the same, aside from the branding. In fact, the transceivers don’t have any real way of failing that would also damage a switch. So there is no problem to use third-party compatible transceiver.
 
Compatible SFP transceiver modules offered by fiber-mart.com are third-party and fully compatible with major brands (Cisco, HP, NETGEAR, Finisar, Juniper, etc.) and backed by a Lifetime Warranty. fiber-mart.com have a large selection of compatible SFP modules in stock and can ship within 24 hours.
 

2019年6月19日星期三

Copper SFP Transceiver for 1000BASE Applications

In the past, because of low cost and compatibility with existing LANs, 100Mb/s Ethernet was very popular. As people’s increasing demands for faster delivery of information, high bandwidth Ethernet LAN is evolving. 1000BASE (1 Gbps Gigabit Ethernet) came around and brought Ethernet technology to a new stage. Gigabit Ethernet, as the new networking techology was a viable solution for increased bandwidth requirements. Early implementation of the technology will be in high-speed backbones and specialized workgroups. The initial standards of 1000BASE were created and maintained by the 802.3z working group of the IEEE LAN-MAN Standards Committee in June 1998.
 
Now that 1000Mb/s Ethernet has been applied generally, the corresponding equipment like the cable and transceiver are needed to make the network the most effective.
 
Before 2000, SFP optical transceiver module combines transmit and receive functions in a compact, low power, low cost package format. Now it’s widely applied in Fibre Channel, Gigabit Ethernet (GbE), and SONET/SDH and supports data rates between 125 Mb/s and 4 Gb/s. Later some manufacturers make SFP ports with copper transceivers. The copper small form factor pluggable (SFP) transceiver can maintain both configuration flexibility and high port utilization with low cost for optical networks. Due to these advantages, the need for copper SFP transceivers increases obviously.
 
Configuration Flexibility with High Port-level
When there is no copper transceiver, users who want to support Ethernet traffic over both copper and fiber should offer two different line cards dedicated to one media or the other or, alternatively, hybrid cards with a fixed number of copper ports and optical cages. But this way is not very efficient because the available ports for each type of media rarely matched the network’s constantly evolving topologies.
 
In today’s network environments, systems must deal with the ongoing convergence of data, voice, and video traffic as well as topologies that mix Internet Protocol (IP) with legacy PDH traffic and integrate specialized requirements such as Fibre Channel or ATM. As GbE switches, routers, and multi-service provisioning platforms (MSPPs), for example, must provide port-level flexibility for handling both fiber and copper interfaces, thus copper SFP transceiver becomes the best way to optimize port-level flexibility.
 
A Cisco copper SFP and an optical SFP provide exactly the same physical and electrical interface for any port on the line card. This just needs a single line card design that can handle the entire spectrum of copper and fiber connections. The port utilization copper SFP transceiver can more efficiently to accommodate the changing network requirements.
 
Low Cost
 
The traditional dedicated line card approach increases inventory costs because it has low level of field reconfiguration. Copper SFP transceiver and a common line card design for all ports clearly reduce the inventory costs as well as complete the copper to fiber reconfiguration.
 
All in all, copper SFP transceiver has the advantages such as increased port density, improved system utilization, and low overall costs. Copper SFP transceiver offers users a level of flexibility that did not exist before. So Copper SFP transceiver will still gain its popularity.