Author: Anneli

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Optical fiber communication: the characteristics of intelligent optical network

Since ASON (Intelligent Optical Network) is built on various transmission technologies, that is, an independent control plane is added on the transmission plane SDH and the Optical Transport Network (OTN), it supports various types of transmission networks currently available. Services for rate and different signal characteristics (such as format, bit rate, etc.). The ASON network can provide a fixed bandwidth transmission channel between two client network elements, the channel being defined between the input access point and the output access point of the optical network.

According to the transmission mode of light in the optical fiber, it can be divided into single mode fiber and multimode fiber.

The ASON business has the following aspects:

SDH service, supporting SDH connection particles VC-n and VC-n-Xv defined by G.707;

OTN service, supporting OTN connection particles ODUk and ODUk-n-Xv defined by G.709;

Transparent or opaque optical wavelength service;

10Mb/s, 100Mb/s, 1Gb/s and 10Gb/s Ethernet services;

Storage Area Network (SAN) services based on Fiber Optic Connection (FICON), Enterprise System Connectivity (ESCON), and Fibre Channel (FC).

ASON is scalable to new business types.

ASON can support multiple types of business models, each with its own business attributes, target market, and business management needs.

Business connection topology type

To support enhanced services (such as bandwidth on demand allocation, diversity circuit assignments, and bundled connections, etc.), ASON should support the separation of call and connection control. The separation of call and connection control can reduce excessive call control information for intermediate connection control nodes, eliminating the heavy burden of decoding and interpreting messages. The connection topology types supported by ASON include bidirectional point-to-point connections, unidirectional point-to-point connections, and unidirectional point-to-multipoint connections.

Since the call and the connection are separated, one call can correspond to multiple connections, and the current two-way point-to-point connection is the most important connection.

Business connection type

The ASON network supports three types of service network connections: permanent connection (PC), switched connection (SC), and soft permanent connection (SPC).

Both PC and SPC connections are managed by the management plane. The difference between PC and SPC is whether the connection is established in the optical network by using network management commands or real-time signaling. These two methods are service connections initiated by the operator.

The SC connection is initiated by the UNI signaling interface, and the service request of the user is sent to the operator through the UNI of the control plane (including the signaling proxy), that is, the user directly initiates the establishment of the service connection.

Business level

The current transmission network cannot formulate a corresponding tariff policy according to the service level, which causes waste of resource allocation, and the ASON network can conveniently divide the priority of the service circuit to provide a transmission service circuit with a service quality agreement (SLA). Customers have different requirements for the reliability of different connections. These requirements can be expressed in terms of “service level”. In an ASON network, the service level is mainly achieved by mapping to different recovery, protection options, and priority of related connections, such as establishing priority, maintaining priority (whether it can be pre-idle), and restoring priority.

The establishment of the priority mainly refers to the establishment response time of the service, which is to establish a service connection in the day, hour or minute.

Maintaining the priority (whether it can be pre-idle) mainly refers to whether the system will be idle to carry more important services in the event of other system failures, and the service connection itself has no protection.

Recovery priority is the recovery time and recovery level (such as the percentage of recovered services) in the event of a system failure.

Mapping a single business class to a range of protection and recovery options, each with a different choice. The control plane supports setting based on the priority of each link and supports bandwidth resource reservation as a recovery purpose and normalization of the failed repair route. Commonly supported service connection levels include: dedicated connections (1+1 and 1:1), shared protection (1: N and M: N), unprotected (transmitted on the primary circuit), unprotected services (in the protection circuit) On the transfer) and so on.

Service access method

In order to connect the service to the ASON network, the user first needs to establish a physical connection with the carrier network on the transport plane. According to the location of the carrier network and the customer, the service access can take intra-office access (the optical network element and the client network element are in one place), the direct remote access (with a dedicated link to the user end), and the connection Remote access to the subnet and dual-homing access.

ASON must support dual-homing access. Multiple addresses should not be required for dual-homing access for the same client device. Dual-homing access is a special case of access. The main purpose of adopting dual-homing access is to enhance the survivability of the network. When access fails, the customer’s service can rely on other access without interruption. Client devices can access the core network/operator in a dual-homed manner (two different paths).

From a security perspective, network resources should avoid unauthorized access. Service access control is a mechanism that restricts and controls the entity’s attempts to access network resources, especially through the UNI and external network node interfaces (E-NNI).

The Connection Admission Control (CAC) feature should support the following security features.

1. CAC applies to all entities accessing network resources through UNI (or E-NNI). The CAC includes an entity authentication function to prevent an imposter from fraudulently using network resources by pretending another entity. An authenticated entity will be given a service access level based on configurable policy management.

2. Mechanisms should be provided on the UNI and Network Node Interface (NNI) to ensure client authentication and link information integrity, such as link setup, teardown, and signaling information, for connection management and to prevent service intrusion. The UNI and E-NNI should also include CAC-based application charging information to prevent forgery of connection management information.

3. Each entity can utilize network resources through the authorization of the operator management policy.

 

Original Article Source https://www.mscbsc.com/viewnews-77189.html

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Introduction to 100G QSFP28 DAC Cable


       From providing flawless, high-flow media to real-time connectivity with customers around the world, today’s data centers require ultra-high speed. In order to provide a low-cost solution for data centers to connect switches, Ethernet switch vendors need to maximize the density of optical transceiver ports on their devices. This allows them to provide the maximum number of channels and the lowest cost per bit of traffic. The lowest cost of connecting 100G traffic is to use the 100G QSFP28 DAC Cable.

What is QSFP28 DAC?

QSFP28 DAC stands for 100G QSFP28 direct attach copper cable. 100G QSFP28 DAC is also called 100G QSFP DAC or 100G QSFP+ Copper Cable.
It is compliant with 100G Ethernet (100GBASE-CR4) specifications. So sometimes it is called 100GBASE-CR4 QSFP Cable. It contains four high-speed copper pairs, each operating at data rates of up to 25GbE. So the QSFP28 DAC cable assembly is suitable for power-efficient connectivity for short distance interconnects, such as data center, networking, and high-performance computing application.

What Is 100GBASE-CR4?

100GBASE-CR4 is one of the 100G Ethernet interface types. It is a standard of 100GBASE-R encoding and Clause 91 RS‑FEC over four lanes of shielded twin-axial copper cabling. It is defined as 4 x 25 Gb/s over copper cable per IEEE P802.3bj. 100GBASE-CR4 is different from 100BASE-KR4 that achieve 4 x 25 GB/s over the backplane. 100G QSFP28 DAC is 100GABSE-CR4 Cable that supports a max length of 5 meters.

QSFP28 DAC Types

QSFP28 DAC cable is available in two main types, QSFP28 direct attach a cable and QSFP28 breakout copper cable.

TypesLengthConnectorDatarate
QSFP28 direct attach cable1M~5MQSFP28100Gb/s
QSFP28 to 4 SFP28 breakout cable1M~5MQSFP28-SFP28100Gb/s for QSFP28, 25Gb/s for SFP28
  • 100G QSFP28 DAC Cable

Fig 1. 100G QSFP28 to SFP28 Breakout Cable & 100G QSFP28 DAC

What is the difference between QSFP28 DAC and 100G QSFP DAC?

In fact, they are the same. Sometimes QSFP28 DAC is also called 100G QSFP DAC or 100G QSFP+ DAC. The “QSFP” form factor was originally defined for <10G speeds. When it was adopted for 40G, the name became QSFP+ to denote the higher aggregate performance. The same “QSFP” form factor was later adopted for 100G but the electrical interface had to be upgraded to handle 25Gbps/lane. The electrical interface for 100G can handle up to 28Gbps, hence the engineering and industry name is QSFP28.

In Conclusion

100G QSFP28 DACs delivers aggregate data bandwidth up to 100 Gbps (4x 25 Gbps) with passive copper assemblies. They provide an ideal solution that allows 100G switches and routers to be used within the data center, with low power consumption and a maximum port count. As a pioneer in 100G QSFP DAC, OPTCORE manufactures a wide line of 100G copper cables with high quality and very competitive pricing. We are ready to be one of a reliable vendor for data center player.

Original Article Source https://www.optcore.net/archive25997/

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Short-distance plastic optical fiber communication system

Compared with cables, optical fibers have many advantages as transmission media. However, quartz fiber for common communication is difficult to connect, expensive, and expensive to install and maintain, and cannot be widely used for short-distance data communication or desktop data connection. Plastic optical fiber not only has the advantages of optical fiber but also has a diameter of generally 0.3 to 3 mm. The large diameter is suitable for connection, and the coupling efficiency of light is also high. At the same time, it is also soft, bending resistant, shock resistant, radiation resistant, and inexpensive. Convenient construction and other advantages can replace the traditional quartz fiber and copper cable to a certain extent. Therefore, the plastic optical fiber communication system is very suitable for short-distance (100m or so), medium and small capacity (several Kb/s to 100Mb/s), low-cost (tens of dollars) desktop data connection, and data between devices and device internal bus. connection.

Advantages of plastic optical fiber transmission systems After replacing cable connections with plastic optical fiber communication systems, the performance of the equipment will be improved in the following aspects.

● Improve the equipment’s ability to resist electromagnetic interference and nuclear radiation.

● No crosstalk. Optical cables are used to transmit signals without crosstalk between the signals.

● Lighten the weight of the system. The weight of a 1500m diameter 1mm plastic fiber is less than 2kg.

● Strong anti-lightning ability. The metal-free cable itself is a good insulator, and even if it is exposed to the outside, it will not cause lightning to damage the equipment.

System Description of Plastic Optical Fiber Communication The basic components of a plastic optical fiber communication system is: optical transmitters, optical receivers, plastic optical fibers, and some passive components. An optical transmitter converts an electrical signal (such as a TTL level signal) into an optical signal that is coupled into a plastic optical fiber and transmitted through a plastic optical fiber to an optical receiver that reduces the optical signal to an electrical signal (eg, TTL) Level signal).

The plastic optical fiber communication system focuses on short-distance communication, low cost, simple operation, and high reliability, so it is completely different from the quartz optical fiber communication system in the realization of the specific system.

    Plastic optical fiber communication transceiver

The plastic optical fiber transceiver is the core part of the plastic optical fiber communication system, including the optical transmitter and the optical receiver.

1 is a schematic diagram of the structure of an optical transmitter. The light-emitting diode (LED) is a high-brightness surface mount light-emitting diode for common display and has a driving current of less than 20 mA and a center wavelength of 590 nm (orange light). The reason why the 590nm LED is chosen is because the LED of this wavelength is very cheap, and the loss value of the plastic fiber is relatively low at the wavelength of 590 nm. The size of the LED chip is about 1.0mm×1.0mm, which is equivalent to the diameter of the plastic fiber, and it is easy to couple the optical signal into the plastic fiber.

Figure 1 is a schematic diagram of the structure of an optical transmitter

　　The external input TTL level signal is FSK frequency modulated, and the TTL level signal is converted into a carrier signal more suitable for plastic optical fiber transmission to drive the LED illumination. The light signal from the light-emitting diode (LED) is directly coupled into a glass rod of 1.0 mm diameter, which is then coupled into a plastic optical fiber having a diameter of 1.0 mm through a glass rod.

2 is a schematic diagram of the structure of the optical receiver. The photodetector detects the optical signal and generates an induced current, and then is amplified by the amplification module in two stages, and is input to the FSK demodulation module to be demodulated by the flip-flop. The demodulated signal still contains high-frequency interference, which is filtered by the filter module and then judged by the decision module to be restored to the input TTL signal.

Figure 2 Schematic diagram of the optical receiver structure

　　Both of these plastic fiber optic transceiver solutions are targeted for point-to-point connections. The transceiver of the bus type plastic optical fiber communication system should be a bus type. In the photoelectric conversion, the bus type plastic optical fiber communication transceiver and the point-to-point type plastic optical fiber communication transceiver are the same, but the bus type plastic optical fiber communication transceiver is half duplex. In the mode of operation, it has only one optical signal input/output port, or it has only one concave plastic optical fiber movable connector. At this time, the glass rod of the concave plastic optical fiber movable connector is connected with the LED and the Si-PIN. The end face is not a vertical way, but a 45° bevel, so that the beam can be split into two, one way to Si-PIN, all the way to the LED. Figure 3 is a schematic diagram of a bus type of plastic optical fiber communication transceiver.

Figure 3 bus type plastic optical fiber communication transceiver

    Plastic fiber optic patch cord

Plastic fiber optic patch cords are used to connect plastic fiber optic transceivers to plastic fiber optics by coupling optical signals into plastic fibers. Similar to cable connectors, it is divided into two types: concave head and convex head. The recessed plastic optical fiber active connector and the plastic optical fiber communication transceiver are integrated, and the male plastic optical fiber connector is connected to the plastic optical fiber.

The mechanical structure of the plastic optical fiber movable connector can be variously selected. Because the diameter of the plastic optical fiber core is large, the plastic optical fiber movable connector and the currently used quartz optical fiber movable connector can be completely different, and can follow the structure of the current cable connector ( Such as SMA structure), not only the connection loss is small, but also the use of wire clamps and electrician blades, it is convenient to complete the assembly of plastic optical fiber movable connector parts in the field.

    Plastic optical fiber fixed connector

Plastic fiber optic fixed connectors are used for the connection of plastic and plastic fibers. Using a V-groove structure, two plastic optical fibers are placed in a V-shaped groove, and the plastic optical fiber is fixed by a metal material, and then a heat-shrinkable sleeve is packaged to complete the fabrication of a plastic optical fiber fixed connector. The V-groove structure can achieve the purpose of quickly and easily making a plastic optical fiber fixed connector, and the connection loss is not large due to the large diameter (1 mm) of the plastic optical fiber.

   Plastic optical bus branch

Plastic fiber optic bus splitters are used in bus-type plastic fiber optic communication systems. As shown in Fig. 4, the optical input signal of any one port is evenly distributed to other ports after being totally reflected by the glass rod and reflected by the end face of the glass rod. The requirement for the plastic optical fiber bus splitter is that the additional loss is low, the second is that the uniformity of each port is good, and the third is that the structure is simple and the cost is low.

Figure 4 plastic optical fiber bus splitter

    Plastic fiber optic light multimeter

The plastic optical fiber multimeter consists of a light source, an optical power meter, a microprocessor, and a liquid crystal display. The LED is used as the light source and the Si-PIN is used as the detector. It is similar to the fiber optic multimeter currently in use, except that the wavelength range of light used is different and the cost is different.

Key Technology Low-Cost Plastic Optical Fiber Communication Transceivers Plastic optical fiber communication transceivers should be high-sensitivity, bursty receivers and extremely low-cost fiber optic transceivers. The principle of the plastic optical fiber communication transceiver is relatively simple, but requires the circuit cost to be extremely low, and also ensures high receiving sensitivity, high reliability, and small size. At present, the system has realized the transmission sensitivity of the transmitting end -10dBm, and the receiving sensitivity of the receiving end is -40dBm (10E-9 error rate).

    Plastic fiber optic patch cord

The key technology of the plastic fiber optic patch cord is that it is simple to manufacture and low in cost. It can be easily assembled on site by using simple tools such as wire clamps and electrician blades. Its connection loss is less than 1dB.

Plastic Optical Fiber Bus Splitter The plastic optical fiber bus splitter is a key component for implementing a bus-type plastic optical fiber communication system. The optical input signal of any one port is evenly distributed to other ports.

It seems to be the 1×N optical splitter that is commonly used nowadays. In fact, the principle and function are different. A 1×N optical splitter distributes the optical input signal of one port evenly to other ports or concentrates the optical input signals of N ports onto one port, and the plastic optical fiber bus splitter requires any port. The optical input signal is evenly distributed to other ports. It is a half-duplex device. In the normal operation of the bus-type plastic optical fiber communication system, only one port has an optical signal output, and the remaining ports are input optical signals. It is used in conjunction with a bus-type plastic optical transceiver to form a bus-type plastic optical fiber communication system. It not only requires a simple structure but also requires a low cost.

Original Article Source http://cabling.qianjia.com/html/2009-09/09_192636.html

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The importance of using fiber optic color codes in data centers

Using fiber optic color codes in the data center can effectively help technicians better manage fiber optic cables and reduce human error. Workers can easily obtain information about the device by viewing the cable color code, which simplifies the redundant inspection process. Making full use of the optical cable color coding system can save a lot of working time. The widely accepted color coding system and its important functions are described below.

　　Introduction to Cable Color Code System

Fibers, bundles, and straps in fiber optic cables are often labeled with different color codes for easy identification. Many countries use this color code system. All of these systems are characterized by the use of 12 different colors to identify fibers that are gathered together in a common bundle, such as bundle tubes, drawstrings, yarn rolls, or other types of bundles.

Different countries and regions use different color code standards. For example, in Sweden, the S12 standard is used for micro cables and nanocables. The Type E standard is defined by Televerket and Ericsson used in Sweden. Countries such as Finland use the FIN2012 standard, but a color coding system generally accepted in the world, namely the TIA/EIA-598 standard.

TIA/EIA-598 color code specifications The following figure shows the cable color coding for the TIA/EIA-598 standard. If more than 12 fibers or bundles are to be distinguished, the color sequence is usually repeated on the fibers and bundles with ring marks or lines. As for the cable jacket, the orange, yellow, light green and black color scales are used for distinguishing.

The role of the cable color code in the data center

(1) Differentiating the cable grade

As mentioned above, the outer jacket color code can identify the cable grade. The OM1/OM2 cable is usually orange-sheathed, the OM3/OM4 cable is light green, the single-mode cable is yellow, and the hybrid cable (indoor/outdoor and outdoor cables) is black. One thing to note is that mixing OM1 and OM2 or OM3 and OM4 cables can be cumbersome to handle.

(2) Identify the fiber jumper

Marking fiber patch cords with color codes can reduce the possibility of human error. For example, a mission-critical jumper can be highlighted in red and the technician can be shown that the red jumper can only be moved with proper authorization or supervision. Again, the color of the fiber optic connector needs to be consistent with the fiber-level color standard, which will make it easier for technicians to use the correct connector on the fiber optic cable.

(3) Differentiating different ports

Color-coded port icons help identify different network routes based on internal requirements. Network management can be simplified by marking each patch panel port.

(4) Distinguishing Connector Sheaths

Staff can use color codes on the boot connectors to help technicians maintain proper parallel grouping of switch ports, making routine maintenance, movement, additions, and changes easier. If you change the connector color, you need to make sure that the cable color represents the fiber grade to avoid confusion. Workers can also change the color of the boot connector to differentiate between different deployments of the optical network, allowing technicians to easily view the contrast within the panel.

Conclusion

Visual management is more intuitive for experts who manage and maintain data centers. The fiber color code provides an ideal and easy way to solve fiber routing problems. Inside the cable, the fiber buffer can also be color coded in standard colors for easy connection and splicing. Therefore, if people are still plagued by problems such as fiber jumpers, it is a good idea to use fiber color code systems.

Edit: Harris

Original Article Source http://www.jifang360.com/news/2019412/n6592117478.html

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What is the difference between a video optical transceiver and a fiber optic transceiver?

Do you know the difference between video optical transceivers and optical transceivers? Today, Xiaobian introduces their specific differences from the following aspects. First, we must talk about the difference between video optical transceivers and optical transceivers from their concept.

The following are the differences between video optical transceivers and fiber optic transceivers:

1. The optical transceiver is mainly applied to the network, one end is connected to the optical fiber, and the other end is connected to the switch, mainly a network signal.

The optical transceiver can transmit video signals, 485 control signals, network signals, alarm signals, audio signals, switching quantities, and the like. The optical transceiver on the monitoring is generally: one end of the optical transmitter is connected to the camera, the other end is connected to the optical fiber, one end of the optical receiver is connected to the optical fiber, and the other end is connected to the display device.

2. The first talk about the optical transceiver, there are two conventional optical transceivers.

a. PDH optical transceiver for transmitting data signals.

b. The video optical transceiver is used to transmit video surveillance signals. The optical transceiver is a receiver (receiver and transmitter), that is, the main function of the video receiver is to convert the optical signal into an electrical signal (D/A). The main function of the transmitter, that is, the video transmitter, is to convert the electrical signal into an optical signal (A/D).

Fiber Transceiver

Earlier, the optical transceiver was used to transmit video signals. Then the fiber optic transceiver is used to transmit Ethernet signals. Although they are all photoelectric conversion, the protocols and principles of the electrical signals are different, and the signals transmitted on the optical path are also different.

3. One end of the optical transceiver is connected to the optical transmission system, and the other end (user end) comes out with a 10/100M Ethernet interface. Optical fiber transceivers are all used to achieve photoelectric signal conversion. The main principle of fiber optic transceivers is that fiber optic transceivers implemented by optocoupler usually have the following basic features.

a. Provide ultra-low latency data transmission.

b. Fully transparent to network protocols.

c. Use a dedicated ASIC chip to achieve data line-speed forwarding. The programmable ASIC combines multiple functions onto a single chip, which has the advantages of simple design, high reliability, and low power consumption, which enables the device to achieve higher performance and lower cost.

d. The equipment adopts 1+1 power supply design, supports ultra-wide power supply voltage, realizes power protection and automatic switching.

e. Support an ultra-wide operating temperature range.

f. Support full transmission distance (0 ~ 120 km)

The optical transceiver is a device that converts multiple E1 (a data transmission standard of a trunk line, usually at a rate of 2.048 Mbps, which is adopted in China and Europe) into an optical signal and transmits it. The price of the optical transceiver is different depending on the number of E1 ports transmitted. Generally, the smallest optical transceiver can transmit 4 E1s, and the largest optical transceiver can transmit 4032 E1s.

Optical transceivers are divided into three categories: PDH, SPDH, SDH.

PDH (Plesiochronous Digital Hierarchy) optical transceivers are small-capacity optical transceivers, which are generally used in pairs, also called point-to-point applications. The capacity is generally 4E1, 8E1, and 16E1.

The SDH (Synchronous Digital Hierarchy) optical transceiver has a large capacity, generally 16E1 to 4032E1.

SPDH (Synchronous Plesiochronous Digital Hierarchy) optical transceiver, between PDH and SDH. SPDH is a PDH transmission system with SDH (Synchronous Digital Series) features (based on the principle of code rate adjustment of PDH, and at the same time adopts some networking technologies in SDH).

Original Article Source  http://bbs.elecfans.com/jishu_1142152_1_1.html

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Optical Fiber Types

There are two classes of Optical Fiber:
Single-Mode Fiber: generally called SMF, it is used for long distance communication
Multi-Mode Fiber: generally called MMF, it is used for short distances less than 500 meters
The advantage of MMF is that it is cheaper than SMF, and multimode connectors are cheaper and easier to terminate reliably in the field.

In recent years, there are new optical cables called active optical cables (AOC). These have the optical electronics already connected, eliminating the connectors between the cable and the optical transceiver. They will plug into standard optical transceiver sockets. Because of the manufacturer can match the electronics to the required length and type of cable, the cost of these new active optical cables is lower than other optical solutions, therefore more and more applications are deployed.

There are different types of fiber optic fiber depending on the type of network and transfer distances:
10GBASE-SR – a port type for short range multimode fiber that covers the following distances based on the grade of optical fiber cabling:
FDDI -62.5 microns, reach of approximately 26 meters
OM1 62.5 microns – a reach of approximately 33 meters
OM2 50 microns – a reach of approximately 82 meters
OM3 50 microns – a reach of approximately 300 meters
OM4 50 microns – a reach of approximately 400 meters
In fact, most of the implementations prefer to OM3 and OM4 for fiber optical cabling to longer transfer distance.
10GBASE-LR: a port type for long range single-mode fiber, supports the reach of approximately 10 kilometers (6.2 miles).
10GBASE-LRM: a port type for long range multi-mode fiber, supports distances up to approximately 220 meters.
10GBASE-ER: a port type for extended reach single-mode fiber, supports the reach of approximately 40km.
10GBASE-ZR: a port type for non-standard extended reach single-mode fiber, supports the reach of approximately 80km.
10GBASE-LX4: a port type for multimode fiber and single-mode fiber, supports reach of approximately 300 meters (980 ft) over FDDI-grade, OM1, OM2, and OM3 multi-mode cabling and 10 kilometers ( 6.2 miles ) over SMF.
SFP+ Direct Attach
Also known as 10G SFP+ Cu, 10GBase-CR, or 10GBase-CX1, SFP+, or 10GbE Cu SFP cables.

SFP+ Direct Attach Cable uses a copper 10GbE cable that comes as active or passive twin-ax cable assembly and connects directly into an SFP+ housing.

Active cables are copper cables that have a silicon chip to boost the performance of the cable. Without a chip, the cable is considered a ‘passive’ cable. Passive cables are more susceptible to degradation due to attenuation and crosstalk. This active boosting allows cables to be more compact, thinner, longer, and transmit data faster than their passive equivalents.

SFP+ Direct Attach Cable has a fixed-length cable, typically 3, 5 or 7m in length, and like 10GBASE-CX4, is low power, low cost and low latency with the added advantages of using less bulky cables and of having the small form factor of SFP+.

Passive = 1, 3, 5 Meters
Active = 7, 10,12,15 Meters

Original Article Source https://www.optcore.net/optical-fiber-types/

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OM5 fiber technology standard and data center application

       The ISO and TIA standardization organizations released the latest wiring standards ISO 11801 3rd and TIA-568.0-D in 2017. The new standard removes the traditional OM1, OM2 multimode fiber optic cable and adds OM5 broadband multimode fiber optic cable. ISO reduces the attenuation of OM5 cables from 3.5 dB/km for previous OM3, OM4 cables to 3.0 dB/km, and increases the bandwidth requirement at 953 nm.

　　ISO/IEC JTC1SC25 WG3 new project ISO/IEC TR 11801-9908 has released the first draft of WD to study wiring guidelines for high-speed network applications on multimode fiber, 10/40/100/200/ The transmission distances of OM3, OM4, and OM5 multimode fibers under 400G duplex and parallel network applications were studied.

　　OM5 multimode fiber supports more wavelength channels, so the direction is the same for SWDM4 with four wavelengths or BiDi with dual wavelength. Similar to BiDi for 40G links, SWDM transceivers only require a two-core LC duplex connection, except that SWDM operates on four different wavelengths between 850 nm and 940 nm, one of which is dedicated to The signal is transmitted and the other fiber is dedicated to receiving the signal.

　　OM5 fiber supports both future 400G Ethernet, for higher speed 400G Ethernet applications such as 400G Base-SR4.2 (4 pairs of fiber 2 wavelengths, 50G PAM4 per channel) or 400G Base-SR4.4 (4 For 4 wavelengths of fiber, 25GNRZ for each channel, only 8 cores of OM5 fiber are required. Compared with the first generation of 400G Ethernet 400G Base-SR16 (16 pairs of fibers, each channel transmits 25Gbps), the required number of fibers is only For a quarter of traditional Ethernet, SR16 is a milestone in the development of multimode 400G technology, demonstrating the possibility of multimode technology supporting 400G. In the future 400G mass application market, 400 multimode applications based on 8-core MPO are expected.

　　As the physical transmission medium of data communication, optical fiber provides support for network equipment. The promotion of OM5 fiber cannot be separated from the support of network equipment manufacturers.

　　There are currently two technologies for transmitting high-speed networks with a small amount of fiber on the market: BiDi and SWDM4. From the perspective of the industry chain, OM5 multimode fiber and BiDi and SWDM4 equipment manufacturers form an industry alliance, but whether this ecosystem can mature depends on the shipment of these 40/100G network equipment and the large deployment of OM5 fiber. The OM5 multimode fiber test is identical to the traditional OM3, OM4 multimode fiber test equipment, and test procedures, and the user does not need to purchase additional test equipment.

　　The data center needs to be upgraded to 200/400G or higher in the future. It will have to face many optical module types such as MSA. In the absence of an IEEE standard project, users also need to care about whether there is open and standardized multimode wavelength multiplexing. Technology has emerged, and low-cost VCSEL 100G technology cannot achieve breakthroughs and other issues. Regardless of whether a parallel transmission optical module or a duplex transmission optical module is used in the future, network cabling is an important network infrastructure of the data center. It can be determined that the data center cabling must be open, scalable and flexible to support A variety of network architecture applications.

　　Responsible Editor: DJ Editor

Original Article Source http://www.jifang360.com/news/2019426/n8147118755.html

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The difference between MPO and MTP fiber connection standards

With the rapid development of data centers, applications such as cloud computing and cloud storage have gradually penetrated various industries, and the bandwidth requirements for network communication have also increased rapidly. High-speed, high-capacity, and high-bandwidth often require more space and higher costs. This long-term contradiction, MTP / MPO fiber wiring standard has become the best solution for high density and high bandwidth. There are two kinds of fiber optic connection systems, MTP and MPO, which are very similar in the market. They are compatible with each other to a certain extent, so what is the difference?

The difference between MPO and MTP fiber connection standards
　　MPO (Multi-fiber Pull Off) is the first generation of shrapnel-type multi-core fiber optic connectors designed by NTT Communications Corporation of Japan. It is now the name of a multi-core connector produced by several companies. MTP, a brand registered by USConec, specifically refers to the unique type of MPO connector it produces.

　　What is an MPO connector?

　　MPO is the abbreviation for “multi-fiber pull off”. The ferrule of this connector has more than one core and is mechanically snapped into place.

　　Nowadays, various manufacturers in the market have a variety of MPO designs. The performance and cost of different types of connected products are very different. Some products make their performance more outstanding. Some MPO connectors can match many different brands of products, but some do not. This compatibility depends on how close these connectors are to standard products. For a complete definition of the MPO connector, please refer to the implementation of IEC-61754-7 and EIA/TIA-604-5 (aka FOCIS 5).

　　What is an MT ferrule?

　　The MT is a mechanical docking transmission with a multi-core number (usually 12 cores). The performance of the connector is determined by the accuracy of the fiber alignment and whether the alignment accuracy is stable after the connection. Ultimately, this alignment accuracy is determined by the eccentricity and spacing of the fiber and the matching accuracy of the guide pin and fiber. The performance of any MPO connector can be improved if the deviation of the guide pin and the molding process can be reduced during the production process.

　What is an MTP? Fiber Connector?

　　The MTP connector is a high-performance MPO connector with multiple innovative designs. The MTP fiber connector is enhanced in optical and mechanical performance compared to conventional MPO connectors. The MTP connector is fully compliant with the professional standards of all MPO connectors, including EIA/TIA-604-5 FOCIS 5 and IEC-61754-7.

　　MPO-type connectors are industry-standard, interchangeable MTP connectors, which means that it is possible to replace MPO connectors with MTP connectors for better performance. Most of the MPO connectors that follow the old design have quite limited performance and do not provide the same high performance as MTP fiber connectors.

　　Why is the MTP connector described as a high-performance MPO connector?

　　The performance and usability of the specially designed MTP connector are improved compared to the MPO connector. This design feature of MTP is unique and patented. The main features are as follows:

　　1. The outer frame of the MTP fiber optic connector can be easily removed.

　　The MT ferrule design ensures performance without loss during rework and regrinds during production. Yin-positive can be flexibly changed even after assembly, and the ferrule can be over-interfered after assembly.

　　2, MTP fiber optic connector floating ferrule can improve the transmission performance when mechanical docking. The two connectors can be allowed to maintain good physical contact with the mating ferrules under the influence of external forces.

　　3. The elliptical guide pin (PIN) of the MTP fiber connector is made of stainless steel. The elliptical guide pin can improve the precision of the butt joint and reduce the wear of the guide hole so that the MTP fiber connector can maintain high-performance transmission more permanently.

　　4. There is a metal clip in the MTP fiber connector to fix the push ring. Specific characteristics:

　Prevent the loss of the guide pin;

　　Concentrating the pressure generated by the spring;

　　Preventing the spring from touching the friction fiber during mechanical stretching to cause damage to the fiber;

　　5. The spring design of the MTP fiber optic connector maximizes the band gap of the 12-core and multi-core ribbon applications to prevent fiber damage.

　　6, MTP fiber optic connectors have at least four standard matching parts, can be adapted to different types of fiber optic cable, more practical, including:

　　around the cable with a loose structure;

　　a ribbon cable with an elliptical outer cover;

　Ribbon bare fiber;

　　The ultra-short-tail connector is ideal for applications in tight spaces, reducing volume by 45%.

　　Can the MT ferrule be cleaned in the usual way?

　　The best way to clean the dust and oil on the MT ferrule that affects optical performance is to use an advanced dry cloth cleaning kit, such as NTT-AT OPTIPOP, which is simply because it involves only a single channel. When using the above cleaning components, the contaminants will be completely removed. On the contrary, the use of low-quality fabrics or cotton swabs can remove the contaminants on the surface of the fiber, but the dirt will still exist on the edge of the ferrule, and the ferrule end faces are easily worn, causing serious Data loss.

　　The OPTIPOP series of cleaning components are designed for yin and yang fiber optic connectors and can also be used with single core ceramic ferrules. OPTIPOP cassette and card cleaners use a refillable cleaning cloth that can be used for a long time and is less expensive to clean than traditional cleaning methods.

　　Responsible Editor: DJ Editor

Original Article Source http://www.jifang360.com/news/201562/n330268516.html

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10GBASE-T Cabling vs 10G SFP+ DAC, which one is better?

10GBASE-T vs SFP+ DAC

01
Mar

Some recent advances in information and data center technology are helping to drive demand for 10GbE architectures, including virtualization and server clustering, network convergence, and advanced storage architectures. The Internet is also a major factor, the new forms of Internet-based information delivery and the explosive growth of digital and social media content. For a variety of reasons, 10GbE has become a flexible unified data center architecture.

For 10Gb Ethernet (10GE) switches and NICs, SFP+ transceivers and DAC cables connected to them have been widely used. Compared with 10GBase-T, SFP+ DAC has certain advantages: lower delay, lower power consumption, lower cost, and the technology is now available and stable. 10GBase-T offers a range of different benefits – familiarity, longer reach, and use of structured cabling and patch panels. So, in the end, choose 10G SFP+ DAC or 10GBASE-T for network cabling? This article will discuss this topic.

There are three options for 10GbE interconnect for specific intended uses:

  1.  SFP+ DAC Cable: These connections are ideal for deployment of blade chassis or 10GbE in racks over short distances.
  2.  Fiber cabling: Fiber optic connections are ideal for high traffic aggregate areas such as network backbones.
  3. 10GBase-T: 10GBase-T cabling is the third choice for top-of-rack switches or end-of-row usage models.

About 10GBASE-T

In the early days of Ethernet, there were several PHY standards, including various forms of coaxial cable, but Ethernet was widely adopted only after running on twisted-pair cables and as a point-to-point rather than an unstructured loop. It is practical to connect an Ethernet cable to each desktop next to the telephone line and set all connections in a wire cabinet. The connector for a twisted pair is an RJ45 connector. When Ethernet speed increases to 100 Mbps and then increases to gigabit speed, the same method is still maintained. Although cable requirements continue to evolve to maintain 100-meter distance standards, the basic method of using twisted-pair and RJ45 connectors remains the de facto standard.

10GBase-T requires a newer Cat 7 or Cat 6A up to 100 meters but can work on shorter distance Cat 6, Cat 5E or Cat 5 cables. 10GBASE-T cabling is backward compatible with 1G ports and these ports will still be used for IPMI and other low bandwidth devices. You can get a 10GBASE-T switch and connect everything you have. Used with 10G SFP+ DAC, it is difficult to find two ports that are adequate for all 10G and 1G devices.

Comparing cost

The SFP+ DAC is a lower cost alternative to fiber, but it can only reach 10 meters. It requires the purchase of an adapter card and requires a new top of rack (ToR) switch topology. DAC Cables are much more expensive than structured copper channels and cannot be field terminated. This makes the DAC more expensive than 10GBASE-T. Many networks now have Cat 6 or Cat 6a cabling installed, so they are ready for 10GBase-T. Any existing fiber can be reused for 10GbE. The new Cat 6 or Cat 6a cable can be added at a lower cost than direct-attached dual-axis copper or fiber multi-mode connections. Finally, training and knowledge transfer costs can be reduced because IT personnel are already familiar with Ethernet technology and RJ-45 connectors. Because SFP+ DAC does not have the flexibility and longer distance of 10GBASE-T, it only applies to 10GbE short-distance cabling.

Comparing Latency

The 10GBase-T PHY standard uses block coding to enable data to pass through the cable without error. The block encoding requires reading the data block into the transmitter PHY, running a mathematical function on the data, and sending the encoded data over the link. The opposite happens at the receiving end. The standard specifies 2.6 microseconds for the transmit-receive pair, and the size of the data block indicates that the wait time cannot be improved by approximately 2.0 microseconds per link. The SFP+ DAC cable uses simpler electronics without the need for code blocks. Typical latency is about 300 nanoseconds per link.

By comparison, we find that SFP+ DAC provides lower latency, but 10GBASE-T and SFP+ fiber cabling provides higher latency

Comparing Distance

Use the latest Cat 6A or Cat 7 cable, 10GBase-T up to 100 meters. The standard has been designed to allow patch panels and jumper cables. The SFP+ DAC provides a maximum distance of 10 meters (about 33 feet) based on passive copper cable. There are no patch panels used with DACs.

Comparing Flexibility

SFP+ DAC is not backward-compatible with existing GbE switches and only used for 10GbE switch.

Where rose, 10GBASE-T SFP+ is backward compatible with existing 1 GbE networks. Therefore, 10GBASE-T cabling offers the most flexibility and the lowest cost media.

Conclusion

From the comparison, we know that both 10GBASE-T cabling and 10G SFP+ DAC have their own advantages. SFP+ copper cable cabling is more suitable for use in data centers application, 10GBASE-T cabling will be better for wiring closets because of its flexibility and cost.

Original Article Source https://www.optcore.net/10gbase-t-cabling-vs-10g-sfp-dac/

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Advantages of MPO/MTP cable in 5G data center

In the 2G/3G/4G era, mobile communications are mainly deployed in the form of voice and data services. With the coming of 5G, the advantages in transmission speed and delay have been greatly improved, enabling 5G to be launched in more aspects, such as VR/AR, autonomous driving, intelligent manufacturing, smart home, Internet of things, etc. field. In the 5G laying, the demand for fiber optic cable will also grow rapidly. Among them, the MPO/MTP cable with advantages has begun to gain more attention. This article will take a closer look at the advantages of MPO/MTP cables in 5G data centers.

　Seven advantages of applying MPO/MTP cables in the data center:

　　1. Protection of the effectiveness and safety of the investment. Although the application of MPO/MTP cable provides high requirements for the integrator’s preliminary and actual site survey capabilities, it can also fully protect the investor’s control over the project and the right to use the product. To avoid material waste and risk of project investment.

　　2. Economically applicable, in general, the MPO/MTP pre-end method does not add additional costs.

　　3. Easy to operate, easy to install, save installation time, and plug and play. We can make a simple comparison, such as laying a 288-core fiber optic cable, 3 construction workers, 2 sets of equipment, using traditional fusion fiber method, laying about 2 hours, and the time required for the fusion fiber plus installation is about 8 Hours, a total of about 10 hours, and if the MPO/MTP pre-cast cable is used, the laying time is still 2 hours, but the installation time is greatly reduced, only about 45 minutes, which undoubtedly has a huge advantage in time cost.

　　4. The MPO/MTP pre-cast cable is fully tested in the factory, and no other products are added during the installation process. The field test operation is simple.

　　5. The fiber link protection is sufficient. No solder joints and bare fibers are exposed to the air, and there are no problems such as aging and joint breakage.

　　6. Maintenance is convenient and safe. The mechanical performance of the MPO/MTP pre-end cable splitter is excellent, and the maintenance or operation process will not affect the normal use of the fiber.

　　7. Re-installable and mobile, the splitter of the MPO/MTP pre-cable cable can be quickly inserted and removed and reinstalled as needed.

　　Compared with ordinary fiber optic cable, the main features of MPO/MTP cable are high density and pre-formed end, and finally embodied in MPO/MTP multi-core connector. Throughout the development of the industry, fiber optic connectors have two distinct stages of development: the first phase is to save space and to the direction of miniaturization, fiber optic connectors have evolved from traditional FC, ST, SC to LC, MTRJ. The second phase is not only to save space but also to meet the requirements of multi-core use, fiber optic connectors evolved from LC, MTRJ to MU, MPO/MTP.

　　With the rapid development of 5G, data center interconnection, fiber sensing, and next-generation fiber technology, ultra-large capacity, ultra-high-speed, ultra-long-haul optical transmission networks will become a must for 5G data center construction. Conditions, the dual advantages of MPO/MTP cable in terms of technology and cost are likely to become the mainstream way for operators to build 5G data centers in the future.

　　Editor in charge: Erin

Original Article Source http://www.jifang360.com/news/2019112/n0724114897.html