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  • ARM’s new CPU and GPU will power mobile VR in 2017

     

    ARM, the company that designs the processor architectures used in virtually all mobile devices on the market, has used Computex Taipei 2016 to announce new products that it expects to see deployed in high-end phones next year. The Cortex-A73 CPU and Mali-G71 GPU are designed to increase performance and power efficiency, with a particular view to supporting mobile VR.

    ARM says that its Mali line of GPUs are the most widely used in the world, with over 750 million shipped in 2015. The new Mali-G71 is the first to use the company's third-generation architecture, known as Bifrost. The core allows for 50 percent higher graphics performance, 20 percent better power efficiency, and 40 percent more performance per square mm over ARM's previous Mali GPU. With scaling up to 32 shader cores, ARM says the Mali-G71 can match discrete laptop GPUs like Nvidia's GTX 940M. It's also been designed around the specific problems thrown up by VR, supporting features like 4K resolution, a 120Hz refresh rate, and 4ms graphics pipeline latency.

     

    As for CPUs, ARM is announcing the new Cortex-A73 core, which prioritizes power efficiency. It's up to 30 percent more efficient than the previous Cortex-A72 while offering about 1.3 times the level of peak performance, but ARM has also focused on sustained usage — the A73 offers over twice the performance within its power budget, meaning it doesn't need to be as hasty to slow down to save battery life.

     

    arm slide 2

     

    Although ARM architecture dominates the mobile landscape, there's a good chance you won't see these specific products in your 2017 flagship phone. ARM licenses its architecture and cores separately, meaning companies are free to pick and choose what they like. Apple, for example, licenses ARM architecture but now designs its own custom CPU cores (known as Twister in the most recent A9 processor) and uses PowerVR GPU solutions from Imagination Technologies. Samsung, meanwhile, designs some Exynos processor cores but uses them alongside ARM's Cortex cores and Mali GPU in the international Galaxy S7. And Qualcomm reverted to its own custom Kryo CPU cores in the Snapdragon 820 — which powers the US Galaxy S7 — after using Cortex in the 810.

    All of this is to say that you shouldn't take the performance laid out here by ARM as a benchmark for your next phone, because it'll all depend on how the manufacturers choose to implement the technology. But the new Cortex and Mali products do demonstrate that mobile technology continues to advance in terms of power and efficiency, and that it's adapting to new challenges such as VR.

    ARM expects chips to move into production at the end of the year and appear in shipping devices in early 2017.

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  • 40G QSFP+ Transceiver Modules and DAC/AOC Cables Installation Guide

    To install and remove the transceiver optics in a right way is very necessary to ensure the network to work stably and efficiently. Today, we are going to introduce an installation guide of QSFP transceivers and DAC/AOC cables in 40G network.

    40GbE QSFP+ Transceivers Overview

    40 Gigabit Ethernet (40GbE) aggregation switches are becoming more common in today's data centers. At the heart of the 40GbE network layer is a pair of transceivers connected by a cable. The transceivers are plugged into either network servers or a variety of components including interface cards and switches and connected via the cables such as OM3 and OM4 for multimode application. Additionally DAC (Direct Attach Copper) cables or AOCs (Active Optical Cables) are used for short interconnection as a more cost-effective alternative solution. QSFP+ (Quad Small Form-factor Pluggable Plus) is the most common 40GbE interface type, and also as a high-density 10GbE interface via QSFP+ breakout cables. QSFP+ interfaces a network device (switch, router, media converter or similar device) to a fiber optic or copper cable, supporting data rates from 4x10 Gbps and supports Ethernet, Fibre Channel, InfiniBand and SONET/SDH standards with different data rate options. Compared to CFP (C form-factor pluggable) transceiver modules, QSFP transceiver modules are more compact and more suitable for port-density application. The two basic interface specifications of QSFP+ modules respectively for multimode and single-mode applications are 40GBASE-SR4 and 40GBASE-LR4.

    40GBASE-SR4 QSFP+ Module

    The 40GBASE-SR4 QSFP+ module, conforming to the 802.3ba D3.2 (40GBASE-SR4) standard, provides a 40Gbps optical connection using MPO/MTP® optical connectors. This optical module integrates four data lanes in each direction with 40Gbps aggregate bandwidth and each lane can operate at 10.3125 Gbps. It is used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables (transmission distance can be up to 100 meters using OM3 fiber or up to 150 meters using OM4 fiber).

     

    40GBASE-LR4 QSFP+ Module

    The 40GBBASE-LR4 QSFP+ module, conforming to the 802.3ba (40GBASE-LR4) standard, provides a 40Gbps optical connection using LC optical connectors. This optical module integrates four data lanes in each direction with 40Gbps aggregate bandwidth and each lane can operate at 10.3125 Gbps. It is most commonly deployed between data center or IXP sites with single-mode fiber up to 10 km.

     In addition, to satisfy a number of different objectives including support for MMF and SMF compatibility, there are other types of QSFP+ modules offered by different vendors.

    How to Install/Remove QSFP+ Transceivers and DAC/AOC Cables
     
    Preparations

    To protect a QSFP+ module or cable from ESD (electro-static discharge) damage, before installing or removing a QSFP+ module or cable, be remembered that always wear an ESD wrist strap and make sure that it makes good skin contact and is securely grounded (If you are using ESD gloves, wear the wrist strap outside the ESD glove).

    To Install or Remove a QSFP+ Transceiver Module

    There are two types of clasp designed for a QSFP+ transceiver module—plastic clasp or a metallic clasp. Here uses the metallic clasp type as an example.

    To Install a QSFP+ Transceiver Module

    Step 1. Remove the QSFP+ module from its antistatic container and remove the dust covers from the module optical connector.
    Step 2. Remove any rubber dust covers from the port where you are installing the QSFP+ module.
    Step 3. Pivot the clasp of the module up. (Skip this step if the clasp is plastic.)
    Step 4. Align the module with the port in the chassis, as shown in Figure 1.

    Figure 1. Aligning the module with the port
    Figure 1. Aligning the module with the port

    Step 5. Holding the module, gently push in the module until it is firmly seated in the port.(see Figure 2.)

    Figure 2. Install the QSFP+ module to port
    Figure 2. Install the QSFP+ module to port

    Step 6. Immediately attach the patch cord with MPO connector or duplex LC connector to the QSFP+ transceiver module.(see Figure 3.)

    Figure 3. Install the patch cord to the module
    Figure 3. Install the patch cord to the module

    Note: Install the dust plug for the transceiver module if you are not to install an optical fiber into it.

    To Remove a QSFP+ Transceiver Module

    Step 1. Remove the optical fiber if any.
    Step 2. Pivot the clasp of the module down to the horizontal position. (Skip this step if the clasp is plastic.)
    Step 3. Holding the module, gently pull the module out of the port. (Figure 4)
    Step 4. Place the QSFP+ transceiver into an antistatic bag.

    Figure 4. Remove the QSFP+ module
    Figure 4. Remove the QSFP+ module

    To Install or Remove a 40G QSFP+ Cable

    The installation and removal procedures are the same for QSFP+ DAC cables and QSFP+ AOC cables. Here uses a QSFP+ DAC cable as an example:

    To Install a QSFP+ DAC Cable

    Step 1. Align the QSFP+ transceiver module (with the clasp on top) at one end of the cable with the port in the chassis, as shown in Figure 5.
    Step 2. Horizontally and gently push in the module to fully seat it in the port.

    Figure 5. Installing a QSFP+ DAC cable
    Figure 5. Installing a QSFP+ DAC cable

    To remove a QSFP+ DAC Cable

    Step 1. Gently press and release the QSFP+ transceiver module.(see Figure 6.)
    Step 2. Holding the cable, gently pull the clasp on the cable to pull out the transceiver module.

    Figure 6. Removing a QSFP+ DAC cable
    Figure 6. Removing a QSFP+ DAC cable

    To Install or Remove a 40G QSFP+ to 4x10G SFP+ Cable

    40G QSFP+ to 4x10G SFP+ cable combines one 40G QSFP+ module on one end and four 10G SFP+ module on the other end. The installation and removal procedures of 40G QSFP+ connector are introdueced above. Here only introduced the installation and removal of 10G SFP+ module:

    To Install an SFP+ Transceiver Module

    Step 1. Align the module with the SFP+ port, with the golden plating facing the spring tab (see Figure 7.) in the SFP+ port. If the chassis has two rows of ports, the spring tab in a port is on the bottom in the upper row and on the top in the lower row.
    Step 2. Slightly press the module against the spring tab so you can push the module straight into the port.

    Figure 7. Installing an SFP+ transceiver module
    Figure 7. Installing an SFP+ transceiver module

    To Remove an SFP+ Transceiver Module

    Step 1. Press the module with your thumb, as shown by callout 1 in Figure 8.
    Step 2. Gently pull the clasp on the cable to pull out the transceiver module, as shown by callout 2 in Figure 8.

    Figure 8. Removing an SFP+ transceiver module
    Figure 8. Removing an SFP+ transceiver module

    Verifying the installation

    Execute the display transceiver interface command on the device to verify that the transceiver module or DAC/AOC cable is installed correctly. If the transceiver module and DAC/AOC cable information is displayed correctly, the installation is correct. If an error message is displayed, the installation is incorrect or the transceiver optics is not compatible.

    transceiver interface command

    Conclusion

    As 40 GbE are widely deployed, 40G transceiver optics are ubiquitous. A good practice and correct installation are very important for 40G network system, not only to protect the 40G transceiver optics and device from damage, but also to ensure a stable performance for system. In addition, by executing the display transceiver interface command, we can verify whether the installation is correct. Of course, the premise is that the transceiver optics you use is fully compatible with your device. COMPUFOX offers a comprehensive line of high-compatible 40G transceiver optics, such as 40GBASE-SR4 QSFP+, 40GBASE-LR4 QSFP+ and 40G DACs and AOCs with competitive prices. See Links below:

     

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  • Ethernet Passive Optical Network Tutorial

    EPON is a PON-based network that carries data traffic encapsulated in Ethernet frames. Unlike other PON technologies which are based on the ATM standard, it uses a standard 8b/10b line coding and operates at standard Ethernet speed. This lets you utilize the economies-of-scale of Ethernet, and provides simple, easy-to-manage connectivity to Ethernet-based, IP equipment, both at the customer premises and at the central office.

    EPON Network Structure

    A typical EPON system is composed of OLT, ONU, and ODN (Figure 1).

    EPON Network Structure
    Figure 1. EPON Network Structure

    The OLT(Optical Line Terminal)resides in the Central Office (CO) and connects the optical network to the metropolitan-area network or wide-area network, also known as the backbone or long-haul network. OLT is both a switch or router and a multi-service platform which provides EPON-oriented optical interfaces. Besides the network assembling and access functions, OLT could also perform bandwidth assignments, network security and management configurations according to the customers’ different QoS/SLA requirements.

    The ONU(Optical Network Unit)is located either at the end-user location or at the curb and provides optical interfaces which are connected to the OLT and service interfaces at users’ side such as voice, data and video.

    The ODN(Optical Distributed Network)is an optical distribution network and is mainly composed of one or more passive optical splitters which connects the OLT and ONU. Its function is to split downstream signal from one fiber into several fibers and combine optical upstream signals from multiple fibers into one. Optical splitter is a simple device which needs no power and could work in an all-weather environment. The typical splitters have a splitting ratio of 2, 4, 8, 16 or 32 and be connected to each other. The longest distance the ODN could cover is 20 km.

    EPON Downlink and Uplink Technology

    In an EPON the process of transmitting data downstream from the OLT to multiple ONUs is fundamentally different from transmitting data upstream from multiple ONUs to the OLT.

    In the downstream direction, Ethernet frames transmitted by the OLT pass through a 1:N passive splitter and reach each ONU. N is typically between 4 and 64. This behavior is similar to a shared-medium network. Because Ethernet is broadcast by nature, in the downstream direction (from network to user), it fits perfectly with the Ethernet PON architecture: packets are broadcast by the OLT and extracted by their destination ONU based on the media-access control (MAC) address (Figure 2).

    Downstream Traffic in EPON
    Figure 2. Downstream Traffic in EPON

    In the upstream direction, due to the directional properties of a passive optical combiner, data frames from any ONU will only reach the OLT, and not other ONUs. In that sense, in the upstream direction, the behavior of EPON is similar to that of a point-to-point architecture. However, unlike in a true point-to-point network, in EPON data frames from different ONUs transmitted simultaneously still may collide. Thus, in the upstream direction (from users to 13 network) the ONUs need to employ some arbitration mechanism to avoid data collisions and fairly share the fiber-channel capacity (Figure 3).

    Upstream Traffic in EPON
    Figure 3. Upstream Traffic in EPON

    EPON and ADSL Comparison

    The requirement of bandwidth is increasing crazily with the incoming of digital age. Therefore the current high speed copper cable ADSL (Asymmetric Digital Subscriber Line) cannot meet our needs longer. The bandwidth of ADSL is limited to only a few megabit per second and the upstream and downstream bandwidth are not equal either. However, optical fiber has larger bandwidth and superior transmission capability which reaches gigabit per second. Hence, optical fiber used in access network is the future trend. And since Ethernet is low cost, uncomplicated widely-used in current network, and its application is very popular nowadays. So it is not hard to see that it is feasible and economical to combine them together. EPON technology combines a mature Ethernet technology and high-bandwidth PON technology, which is an ideal access method to achieve integrated services. In the future, highbandwidth business will surely drive up existing EPON which has the rate of 1.25Gbps in both the downstream and upstream directions.

    EPON Technical Advantages

    EPONs are simpler, more efficient, and less expensive than alternate multiservice access solutions. Key advantages of EPONs include the following:

    Higher bandwidth: up to 1.25 Gbps symmetric Ethernet bandwidthLower costs: lower up-front capital equipment and ongoing operational costsMore revenue: broad range of flexible service offerings means higher revenues

     

    With the growing of EPON technology, interaction standards and EPON devices, EPON has entered the large scale application phase driven by the huge market demands. EPON is fit for the access market which is at the end of the fibers and which has a certain density and these markets include FTTH, FTTP, FTTB, FTTN etc.

    EPON becomes a very economical and effective broadband access solution because of its predominance in equipment investment and also the operations, maintenance and etc. It could be said that the EPON technology has become the developing direction of access network’s technologies in the future as an ideal solution for FTTH.

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  • Basics of Fiber Optic Splicing

    Fiber Optics Splicing is becoming  more and more a common skill requirement for cabling technicians. A fiber optic splice is defined by the fact that it gives a permanent or relatively permanent connection between two fiber optic cables. Fiber optic cables might have to be spliced together for a number of reasons—for example, to create a link of a particular length, or to repair a broken cable or connection. As fiber optic cables are generally only manufactured in lengths up to about 5 km, when lengths of 10 km are required, for example, then it is necessary to splice two lengths together to make a permanent connection.

    Classification of Techniques Used for Optical Fiber Splicing

    Mechanical splices
    The mechanical splices are normally used when splices need to be made quickly and easily. Mechanical fiber optic splices can take as little as five minutes to make, although the level of light loss is around ten percent. However this level of better than that which can be obtained using a connector. Some of the sleeves for mechanical fibre optic splices are advertised as allowing connection and disconnection. In this way a mechanical splice may be used in applications where the splice may be less permanent.

     

    Fusion splices
    This type of connection is made by fusing or melting the two ends together. This type of splice uses an electric arc to weld two fiber optic cables together and it requires specialised equipment to perform the splice. Fusion splices offer a lower level of loss and a high degree of permanence. However they require the use of the expensive fusion splicing equipment.

    Mechanisms of Light Loss at Optical Fiber Joint

    When joining optical fibers, the opposed cores must be properly aligned. Optical fiber splice loss occurs mostly in the following manner.

    Poor concentricity
    Poor concentricity of joined optical fibers causes a splice loss. In the case of general purpose single-mode fibers, the value of splice loss is calculated roughly as the square of the amount of misalignment multiplied by 0.2. (For example, if the light source wavelength is 1310 nm, misalignment by 1 µm results in approximately 0.2 dB of loss.)

    Poor concentricity
    Axial run-out
    A splice loss occurs due to an axial run-out between the light axes of optical fibers to be joined. For example, it is necessary to avoid an increased angle at fiber cut end when using an optical fiber cleaver before fusion splicing, since such an angle can result in splicing of optical fibers with run-out.

    Axial run-out
    Gap
    An end gap between optical fibers causes a splice loss. For example, if optical fiber end faces are not correctly butt-joined in mechanical splicing, a splice loss.
     
    An end gap between optical fibers
    Reflection
    An end gap between optical fibers results in 0.6 dB of return loss at the maximum due to the change in refractive index from the optical fiber to the air. In addition, the whole optical fiber ends should be cleaned because loss can also occur due to dirt between optical fiber ends.

    Classification and Principles of Fusion Splices

    Fusion splicing is classified into the two methods, as follows:

    Core alignment

    Optical fiber cores observed with a microscope are positioned with the help of image processing so that they are concentrically aligned. Then, an electric arc is applied to the fiber cores. The fusion splicer used has cameras for observation and positioning in two directions.

    Fs core_alignment.jpg

    Stationary V-groove alignment

    This fusion splicing method uses V-grooves produced with high precision to position and orient optical fibers and utilizes the surface tension of melted optical fibers for alignment effects (cladding alignment). Splices made by this method achieve low loss thanks to the recent advancement of optical fiber production technology, which has improved the dimensional accuracy regarding the placement of core. This method is primarily used for splicing a multi-fiber cable in a single action.

    Fs V-groove.jpg
     

    Tips for Better Splices:

    1. Thoroughly and frequently clean your splicing tools. When working with fiber, keep in mind that particles not visible to the naked eye could cause tremendous problems when working with fiber optics. "Excessive" cleaning of your fiber and tools will save you time and money down the road.
     
    2. Properly maintain and operate your cleaver. The cleaver is your most valuable tool in fiber splicing. Within mechanical splicing you need the proper angle to insure proper end faces or too much light escaping into the air gaps between the two fibers will occur. The index matching gel will eliminate most of the light escape but cannot overcome a low quality cleave. You should expect to spend around $200 to $1,000 for a good quality cleaver suitable for mechanical splicing.
     
    For Fusion splicing, you need an even more precise cleaver to achieve the exceptional low loss (0.05 dB and less). If you have a poor cleave the fiber ends might not melt together properly causing light loss and high reflection problems. Expect to pay $1,000 to $4,000 for a good cleaver to handle the precision required for fusion splicing. Maintaining your cleaver by following manufacturer instructions for cleaning as well as using the tool properly will provide you with a long lasting piece of equipment and ensuring the job is done right the first time.
     
    3. Fusion parameters must be adjusted minimally and methodically (fusion splicing only). If you start changing the fusion parameters on the splicer as soon as there is a hint of a problem you might lose your desired setting. Dirty equipment should be your first check and them continue with the parameters. Fusion time and fusion current are the two key factors for splicing. Different variables of these two factors can produce the same splice results. High time and low current result in the same outcome as high current and low time. Make sure to change one variable at a time and keep checking until you have found the right fusion parameters for your fiber type.
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  • Optics and Cables Selection for Storage Area Network (SAN)

    Optics and cables are the most important infrastructures of network connectivity. In a storage area network (SAN), switches are used between servers and storage devices. This means that you should make connection with optics and cables between the server and switch, storage and switch as well as the switch and switch. Of course, according to different application environments, you should choose different optics and cables in order to get the best performance. Furthermore, you may need to consider the future expansion of your network. Thus, an economical and effective solution of optics and cables are very necessary.

    Key Factors Influencing Your Decision

    Firstly, there are some key factors which will influence your decision. Thus, you must make sure that what your network really requires. As we mentioned above, an SAN has server, storage device and switches. So, what should we consider in every section of the network?

    1. Server
    Bandwidth: Depending on the application load requirements, customers typically decide whether they want 1GbE, 10GbE, or 40GbE. In some cases, the decision may also be dictated by the type of traffic, e.g. DCB (Data center bridging) requires 10GbE or higher.Cost: Servers claim the highest share of devices deployed in any data center. Choosing a lower cost connectivity option results in a much lower initial deployment cost.Power: In any high density server deployment, a connectivity option which consumes lower power results in much lower OpEx.Distance: Servers are typically connected to a switch over a very short distance, i.e. typically within the same rack or, in some cases, within the same row.Cabling Flexibility: Some customer prefer to make their own copper cables due to variable distance requirement. This requirement limits the choice of connectivity to copper cables only.

     

    2. Storage
    Reliability: Typical storage traffic is very sensitive to loss. Even a minor loss of traffic may result in major impact on application performance.Qualification: Storage vendor qualification or recommendation plays an important role in this decision due to reasons such as customer support, peace of mind, etc.Latency: Any time spent in transition is time taken away from data processing. Reducing transition time results in much faster application performance. The result may have a direct impact on customers' bottom line, e.g. faster processing of online orders.

     

    3. Switch
    Bandwidth: On server facing ports, servers typically dictate the per port bandwidth requirement. However, per port bandwidth requirement for the network facing (switch-to-switch) ports denpends on multiple factors including amount of traffic generated by the servers, oversubscription ratios, fiber limitations, ect.Distance: An inter-switch or switch to router connection could range from a few inches to tens of kilometers. Generally, the price of optics increases as the distance increases.Latency: The network topology and application traffic profile (East-west, HPC (High Performance Computing), computer cluster, etc.) and influence the minimun latency that can be tolerated in the network.

     

    • Server to Switch Connectivity Solution

    • Storage to Switch Connectivity Solution

     

     

    • Switch to Switch Connectivity Solution

     

     COMPUFOX Solutions

    COMPUFOX  offers a comprehensive solution of optics and cables which supports your network from 1GbE to 100GbE. We have a great selection of 1000BASE-T/SX/LX SFP, BiDi SFP, 10GBASE-SR/LR SFP+, DWDM SFP+, whole series 40G QSFP+ optics and cables, as well as the 100G CFP2 and CFP4, etc. which help you solve the cost issue in fiber project. Especially the 40G QSFP+ optics, with the passive optic design, they can be compatible with all the equipment of all major brands. In addition, most of them are ready stock. See Links below:

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