Networking trends 2019

1,186 Comments

1. May 10, 2021 at 10:19 am

   Tomi Engdahl says:

   Any opinion on EZ-RJ45 connectors?
   https://arstechnica.com/civis/viewtopic.php?f=10&t=1243807

   I like using these:

   http://www.platinumtools.com/products/100003.php

   The only downside I see is the cost. In my experience they make it faster and easier to make a high quality connection when I need to crimp on my own end for custom cables, especially when using CAT6 cable. Of course, I use pre-made cables whenever possible.

   I have heard some people claiming you cannot certify a cable made with these connectors… sounds like nonsense to me. Not sure why the small exposed ends of the cable that are trimmed flush with the end of the connector would be a problem. I have never needed to certify a cable I have made, I have only felt the need to test in-wall cabling which I terminate using RJ45 jacks or patch panels, not plugs.

   Anyone have an opinion? Any possible way these things could cause a problem?

   If the tips of them ever make contact with something metal, Bad Things could happen. Unless you drop some super-glue on the exposed wires to cover them up somehow…

   We stopped using them where I work because of reliability issues. The tools did not reliably cut all the wires flush and depending on the jack you plugged into you could have intermittent connection issues when the wires weren’t perfectly cut.

   Reply
2. May 10, 2021 at 10:20 am

   Tomi Engdahl says:

   Terminating CAT6 cables with EZ-RJ45
   https://www.youtube.com/watch?v=0vZs5oHyzgU

   How I terminate CAT6 cables with the Platinum Tools EZ-RJ PRO-HD

   EZ-RJ45® using PoE
   https://www.youtube.com/watch?v=DkrFEfwU2YQ

   The patented EZ-RJ45® Connector simplifies twisted pair terminations by allowing the wires to be inserted through the connector and out the front. This allows the technician to easily verify the proper wiring order. Electrical performance of the termination is optimized by pulling the connector down over the cable jacket and seating it tightly in the rear of the connector. Reducing the distance between the wire twists and contacts improves performance! Reduces scrap, no wasted crimps. More reliable, higher performance. Crimp with the patented EZ-RJ45 Crimp Tool…crimps and trims in one cycle. Manufactured in the USA. Patented.

   Reply
3. May 11, 2021 at 12:33 pm

   Tomi Engdahl says:

   The Verge:
   A county-by-county map of the broadband gap in the US shows how lack of fiber stifles economic activity in poor counties which in turn results in disinvestment — A county-by-county look at the broadband gap — If broadband access was a problem before 2020, the pandemic turned it into a crisis.

   This is a map of America’s broadband problem
   A county-by-county look at the broadband gap
   https://www.theverge.com/22418074/broadband-gap-america-map-county-microsoft-data?scrolla=5eb6d68b7fedc32c19ef33b4

   Reply
4. May 11, 2021 at 12:34 pm

   Tomi Engdahl says:

   Welcome to Infrastructure Week
   How to build the future
   https://www.theverge.com/22421637/infrastructure-week-broadband-hospitals-biden-plan-ev-charging

   Reply
5. May 11, 2021 at 4:36 pm

   Tomi Engdahl says:

   Broadband is one of the few things on which a divided Congress can agree. But will that be enough to finally get fast internet into rural America?

   Joe Biden’s Broadband Push Could Be Worth Billions To Wireless And Cable Companies
   https://www.forbes.com/sites/dwightsilverman/2021/05/11/joe-bidens-broadband-push-could-be-worth-billions-to-wireless-and-cable-companies/

   The lack of high-speed internet service in rural areas is derided by Republicans as an economic hardship for their constituents and by Democrats as among the factors that gave rise to the populist message of Donald Trump. Congress has thrown billions of dollars at the problem in the past with only incremental progress. Depending on who’s counting, the number of households today that can’t access broadband internet service ranges between 21 million to 42 million.

   But the COVID-19 pandemic and the tumultuous Trump presidency has made the situation more dire, spotlighting the need for everyone in the United States to have access to the Internet that’s fast enough to work, learn and possibly even build a business online. In a sharply divided Congress, it has become one thing the two parties can agree on.  And it could mean billions of dollars in new business for wireless and cable companies.

   Reply
6. May 14, 2021 at 8:31 am

   Tomi Engdahl says:

   Google wins cloud deal from Elon Musk’s SpaceX for Starlink internet connectivity
   https://www.cnbc.com/2021/05/13/google-cloud-wins-spacex-deal-for-starlink-internet-connectivity.html

   KEY POINTS
   Google announced that its cloud unit has won a deal to supply computing and networking resources to Elon Musk’s SpaceX to help deliver internet service through the latter’s Starlink satellites.
   The Starlink satellite internet will rely on Google’s private fiber-optic network to quickly make connections to cloud services as part of a deal that could last seven years.

   Reply
7. May 14, 2021 at 2:22 pm

   Tomi Engdahl says:

   Why network-on-chip has displaced crossbar switches at scale #SoC #communication #interconnect

   https://www.edn.com/why-network-on-chip-has-displaced-crossbar-switches-at-scale/

   When the number of elements that need to communicate in a chip is small, a simple crossbar approach to the interconnect function is a possible choice. However, when the number of elements in the system starts to grow, and the distance between them becomes large with respect to the intended clock period, crossbars no longer work and a network-on-chip (NoC) approach is required. But let’s have a look at the crossbar first.

   Reply
8. May 15, 2021 at 8:38 am

   Tomi Engdahl says:

   Wireless Communication: Introduction Types And Applications in 2020
   https://circuitdiagrams.in/wireless-communication/

   Wireless Communication is the quickest developing and most dynamic mechanical region in the communication field. This is a technique for sending data starting with one point then onto the next, without using any connections like wires, cables, or any physical medium.

   Reply
9. May 17, 2021 at 8:31 am

   Tomi Engdahl says:

   https://mb.cision.com/Main/17802/3309464/1389148.pdf?utm_medium=email&_hsmi=126707162&_hsenc=p2ANqtz-_gQfdaatkRBte_woOdrTnpe3gLCi1iLyYTvcp49Iuvm9CGzyOCbAVih3FrVFuC2yL7BqLO8_eSwPTGCQZLkidzwb-NVbIDY9aJoI7-DPT6mLgb1uQ&utm_content=126707835&utm_source=hs_email

   We have talked about it for some time – now 400G is here for real as early adopters begin to ramp up the capacity in their networks. I am proud to share the story about POST Luxembourg’s new network, one of the first in the world using 400ZR optics.
   Another exciting development is the launch of Brocade’s Generation 7 FC switches. I expect many Brocade users, especially in the banking and finance segment, to want to seize the benefits of Gen 7.

   Post Luxembourg choses Smartoptics for new 400G state-of-the-art network

   Service provider POST Luxembourg has selected Smartoptics to provide future-proof optical connectivity for its new backbone network. To meet increasing bandwidth requirements from both residential and business users, the new network is designed to fully support 400G. Being one of the first implementations in the world using 400ZR optics the solution enables POST Luxembourg to take a leading position.

   Press release:
   https://mb.cision.com/Main/17802/3309464/1389148.pdf?utm_medium=email&_hsmi=126707162&_hsenc=p2ANqtz-83Xs5YGXd09kxRUcswhFJppVUw-unOTHyz3sf0d1CSwugVLdd86tqXd4Spp_OG_YOY62UPcZzyi6qnC2gUP5FAuJbbe6NyUeumRJmhv8bB2XGIMNY&utm_content=126707835&utm_source=hs_email

   To meet these increased expectations from both consumers and businesses, POST is investing in a
   new, future-proof network, involving a complete infrastructure upgrade, from switches and routers to
   optical connectivity. The vast majority of the optical layer is based on Smartoptics’ flexible DCP-M
   open line system along with embedded optics both supporting the new 400ZR standard.

   Reply
10. May 17, 2021 at 8:33 am

    Tomi Engdahl says:

    What is 400ZR?
    https://www.adva.com/en/products/technology/what-is-400zr

    Aimed predominantly at short-reach, single-span fiber optic links for Data Center Interconnect (DCI), 400ZR is an interoperable networking Implementation Agreement (IA) released by the OIF in March 2020 . It defines a footprint-optimized solution for transporting 400Gb Ethernet over DCI links targeting a minimum of 80 km. Enabled by advanced coherent optical technology design targeting small, pluggable form factor modules such as QSFP-DD and OSFP, 400ZR supports high capacity data transport, matched to 400GE switch port market introduction.

    The last few years have seen significant growth in data center construction, a trend that’s set to continue. Global Content Network (GCN) companies are driving much of this data center build out—operating and evolving their networks to support cloud services on a massive scale.

    As overall data center capacity scales to meet ever-growing demands for processing and storage, data center architectures are becoming increasingly distributed. Performance-critical applications such as business services, Artificial Intelligence (AI) and big data require low latency, high bandwidth East-West architectures to support the vast amount of machine-to-machine Input/Output (I/O) being generated between servers. To maintain application performance, the maximum fiber propagation between distributed data center locations must be limited to about 100 km.

    Although the product form factor is not specified in the IA, as an industry body, the companies contributing to the 400ZR IA have also defined this specification with the aim of fitting the solution, both from a power and area perspective, into mechanical form factors such as the Quad Small Form Factor Pluggable Double Density (QSFP-DD) and Octal Small Form Factor Pluggable (OSFP). These form factors are separately defined by Multi-Source Agreement (MSA) bodies specifying compact mechanical modules that are connectorized and pluggable into a compatible socket in a system platform. With both the small physical size and low total power dissipation budget of a QSFP-DD, the second key GCN requirement for single-span DCI is met.

    , interoperability of 400ZR solutions provides the dual benefits of easing both supply chain management and deployment. These parameters form part of the IA to support the development of interoperable solutions:

    Signaling rate (baud)
    Modulation format
    Total line capacity in Gbps (includes overhead for error correction)
    Specific Forward Error Correction (FEC) algorithms
    Host and line-side interface specifications, data framing and others

    To realize 400ZR, new design techniques are employed for the coherent Digital Signal Processor (DSP) and the electro-optical devices to achieve the low power and small area needed to implement 400 Gbps coherent optical transmission in QSFP-DD and OSFP form factors.

    https://www.adva.com/en/products/technology/what-is-400zr

    Reply
11. May 17, 2021 at 8:38 am

    Tomi Engdahl says:

    Understanding 400ZR/OpenZR+/400ZR+ Optics
    https://www.lightwaveonline.com/optical-tech/transmission/article/14188934/understanding-400zropenzr400zr-optics

    While still early in development, new 400ZR, OpenROADM, and OpenZR+ interface specifications enable WDM line interoperability, so carriers can mix and match coherent interfaces from different vendors across their networks.

    The introduction of 100G coherent optical interfaces in 2010 dramatically expanded network capacity, while at the same time lowering the cost per bit for optical networks. Since then, ongoing improvements in optical technology and coherent DSPs have resulted in wavelength capacities increasing from 100G to over 600G per wavelength. New generations of multi-modulation, multi-baud rate transponders enable flexible WDM line interfaces with capacities close to Shannon limits on every optical route

    While the optical networking industry’s technical achievements over the last 10 years have been impressive, they were also based on proprietary implementations. Each vendor developed their own mix of coherent DSP specifications, optical interfaces specifications, and forward error correction (FEC) algorithms that precluded interoperability between vendor transponders. Open WDM line systems (amplifiers, in-line amplifiers) support transponders from different vendors, often referred to as “alien wavelengths,” but the transponders at both ends of the network have to be paired from the same vendor.

    Since achieving near Shannon limits on performance, much of the recent industry focus has shifted to expanding capacity by using C+L WDM line systems, along with developing pluggable coherent optics to meet growing capacity needs in metro-based data center interconnect (DCI) and cloud applications. While still early in development, new 400ZR, OpenROADM, and OpenZR+ interface specifications enable WDM line interoperability, so carriers can mix and match coherent interfaces from different vendors across their networks.

    Comparing the Options – 400ZR/OpenZR+/Multi-Haul

    The great thing about industry “standards” is there are so many choices available. Currently, several coherent interface specifications have been issued, or are in varying phases of development, including 400ZR, OpenZR+, OpenROADM, and CableLabs P2P. In addition, vendors continue to develop their own proprietary high-performance modes, generically referred to as “400ZR+” or “Multi-Haul DCO” modes.

    Developed by the Optical Interoperability Forum (OIF), the 400ZR specification was one of the first efforts to define an interoperable 400G coherent interface. Released in March 2020, the OIF 400ZR Implementation Agreement defines a 400G coherent interface for use on point-to-point links up to 120 km. The 400ZR target applications include interconnecting local data center caching sites to metro point of presence (POP or backhaul) offices and interconnecting multiple data centers across metro areas.

    A key objective was to ensure 400ZR modules were both cost and size optimized for their intended point-to-point applications and relatively modest distances (<120 km).

    With the OIF 400ZR efforts focused on a single modulation type and line rate (400G) for metro point to point applications, the OpenZR+ and OpenROADM groups focused on higher-performance optical specifications capable of flexible 100G – 400G line rates and longer optical reaches. The recently issued OpenZR+ Multi-Source Agreement provides interoperable 100G, 200G, 300G, and 400G line rates over metro, regional, and long-haul distances, based on a new frame structure utilizing OpenFEC (oFEC) forward error correction and a set of 100-400G optical line specifications. Performance estimates over standard SMF-28 fiber (EDFA only), and under ideal network assumptions, are up to 480 km in 400G mode. When operating over real world networks with varying span distances, 75-GHz channel widths, intermediate ROADM nodes, and allocating ~2 dB spare margins to accommodate component aging, temperature variation, component variance, polarization dependent loss (PDL), polarization mode dispersion (PMD), and nonlinearity impairments, 400G optical reaches are more likely to be in the 300- 400 km range over standard SMF-28 fiber (EDFA only).

    Even higher performance modules are currently under development, referred to as the “Multi-Haul DCO” category. These higher-performance, proprietary modules generally use slightly larger module sizes (CFP2-DCO), higher performance SD-FECs, higher transmit (Tx) launch powers, and high-performance frontend optical components (drivers, transimpedance amplifier, modulators, lasers) to achieve longer optical reaches. At least for now, these higher-performance modules and operating modes remain proprietary to each vendor

    The 400ZR and OpenZR+ specifications were primarily developed to meet the growing capacity requirements of DCI and cloud operators using 100GbE/400GbE client interfaces. For carriers needing to transport OTN client signals (OTU4), OpenROADM and Multi-Haul DCO optical pluggables offer good alternatives, as they support both Ethernet and OTN client signals.

    Module Size is Not Defined

    One of the biggest misconceptions with the new 400ZR and OpenZR+ specifications is that these interfaces are based on QSFP-DD modules, which is not accurate. The new 400ZR and OpenZR+ agreements are “line interface specifications” providing interoperability of the line interface; they do not define or specify the size or type of pluggable module (i.e., box size).

    While efforts were made in the 400ZR specifications to ensure the performance and power consumption limits fit within smaller module sizes, 400ZR interfaces will be available across a wide array of QSFP-DD, OSFP, and CFP2-DCO modules. Networks can operate using 400ZR interfaces with different modules sizes at each end, as the “box size” doesn’t matter from a line interface interoperability standpoint.

    For 400ZR applications, the QSFP-DD module size is projected to be the high-volume leader, due to lower pricing and smaller footprint, compared to the other module size options. Regional and long-haul applications may be better suited for slightly larger module sizes for performance reasons.

    As mentioned previously, the 400ZR specifications were purposely limited to ensure the module power consumption fit within the thermal limits of smaller sized pluggable modules (QSFP-DD). For metro point-to-point applications (<120 km), the 400ZR performance limitations are a desirable tradeoff to achieve smaller, lower-cost coherent modules while still meeting their intended DCI application requirements.

    For OpenZR+ and Multi-Haul optical interfaces, where the optical modules support flexible 100G – 400G line rates and are intended to be used over metro, regional, and long-haul networks, the pluggable module size can have an impact on the overall optical reach.

    Comparing the Tx launch power and OSNR values of smaller-sized modules provides a good example of how module size affects performance. To limit power consumption, both 400ZR and OpenZR+ specifications reduce Tx launch powers to as low as -10 dBm, resulting in a Tx OSNR of approximately 34 dBm. A coherent CFP2-DCO module or card-based transponder provides approximately 0 dBm Tx power and approximately 44 dB Tx OSNR. Since it is the ONSR that ultimately limits a wavelength’s optical reach, the highest performance is achieved by using optics with higher OSNR values at the starting point.

    WDM Node Effects

    The lower Tx power on smaller-sized pluggables does have an impact on node architectures. Most WDM systems require approximately -2 to +2 dBm input power at the client-side add/drop ports for proper operation. The lower input powers from coherent QSFP-DD modules will need to be boosted, either by some type of external amplification prior to the WDM node or by using additional amplifiers within the WDM node add/drop stage

    Coherent Pluggables Benefits

    Increasing capacity requirements in metro-based DCI and cloud applications are driving industry demand for interoperable, pluggable coherent modules that promise improved cost efficiencies and operational benefits, along with the ability to mix and match modules from different vendors. A wide array of new coherent interface specifications, including 400ZR, OpenZR+, and OpenROADM have been developed to meet these new applications. While the “box size” isn’t usually specified in the line interface agreements, QSFP-DD is expected to be a very popular module size for 400ZR optics, with slightly larger modules and card-based transponders better suited for higher performance long-haul applications.

    Reply
12. May 17, 2021 at 8:41 am

    Tomi Engdahl says:

    https://www.oiforum.com/technical-work/hot-topics/400zr-2/

    https://www.neophotonics.com/what-is-400-zr/

    What is 400G ZR? 400G ZR is a simple and low cost standard for transmitting 400 gigabit Ethernet over data center interconnection links up to 100 km using DWDM (dense wavelength division multiplexing) and higher order modulation such as 16 QAM. The solution is proposed to be available in a small form factor modules such as OSFP or DD-QSFP.

    Why is 400G ZR important? 400G ZR reduces cost and complexity for high bandwidth data center interconnects. Higher order modulation and DWDM unlock high bandwidth, but typically require proprietary coordination at both ends of the fiber. With 400G ZR, you can mix-and-match modules at both ends, something that was previously impossible.

    Many datacenters within a campus or a metropolitan area have a growing need to significantly increase bandwidth connections between them. The maximum distance for these data center interconnect (DCI) connections is < 80~100 km. This is a long enough distance that DWDM systems must be used to put many channels on a single fiber. However, the network is relatively simple with mostly point to point connections. And the volumes will be relatively high.

    The Optical Internet Forum (OIF) has stepped into this breach and is defining a standard, called 400ZR, which will ensure interoperability in a coherent DWDM system. Originally the OIF 400ZR committee established a scope to transmit 400GE (Ethernet) over data center interconnection links of 80~100 km. By putting 400G on a single wavelength with the same number of optical components (albeit higher bandwidth) that currently transmit 100G, the cost per bit is greatly reduced. However, due to the high development costs of the DSP, optical components, and transceiver modules, the committee agreed to include specifications to support telecom applications, which has the effect of increasing the total market size even further. This means that 400ZR will likely be the work horse approach for both DCI and the converged edge of telecom and cloud connections. The volumes will be very large, and therefore there is a great deal of interest in developing 400ZR products by multiple companies.

    It is, of course, not the purpose of this blog post to delineate the specs, and the final OIF implementation agreement has not yet been published. Here we will highlight some of the specifications that impact the interoperation between different vendors. The transmission link in general is composed of a DWDM MUX (40-ch 100GHz-spaced or 64-ch 75GHz-spaced) and a booster EDFA at the transmitting side, and a pre-EDFA and a DWDM DEMUX at the receiver side. It can also be a simple duplex dark fibers without DWDM mux/demux and any EDFAs. While we may casually say that 400ZR operates at 64 Gbaud and 16 QAM, the actual specification must be much more precise. 400ZR actually has a baud rate of 59.84375 Gbaud, which is a result of the combined overhead from FEC, OTN framing, etc. 400ZR also has fixed the modulation format to be dual-polarization 16QAM. Unlike some advanced transponders, there is no option to change baud rates and modulation order on the fly to adjust reach and bandwidth. The transmission link distance should be less than approximately 80km, and the link should provide a link OSNR of about 29dB. A shipped coherent transceiver should meet an OSNR (after transmission) of 26dB, thus leaving a 3dB margin for long-term operation.

    This presents many challenges to the DSP vendors: low power (e.g., <7W) and small size. It is generally believed that 7nm CMOS node is needed. The power consumption is reduced not only because of the short transmission distance (therefore much less power consumption for chromatic and polarization dispersion compensation), but also much lower sampling rate at the DAC (digital-to-analog converter) and ADC (analog-to-digital converter). In order for the transceivers to be able to interoperate with each other, the DSP must use the same error correction coding and decoding techniques. To this end, the OIF has selected the approach for FEC (forward error correction) that all 400ZR compliant transceivers must use.

    400ZR may very well be the next big thing in optical communications.

    Reply
13. May 17, 2021 at 12:39 pm

    Tomi Engdahl says:

    Tools troubleshoot industrial Ethernet problems
    Technology ranges from the simple to the sophisticated
    https://www.controleng.com/articles/tools-troubleshoot-industrial-ethernet-problems/?oly_enc_id=0462E3054934E2U

    Due to its inherent reliability, performance and interoperability, Ethernet has rapidly become the communication protocol of choice for automation and control systems in the industrial environment. In fact, recent surveys found that 70% of all newly installed factory automation nodes employ Industrial Ethernet. This includes Industrial Ethernet applications like Modbus TCP/IP, EtherCat, EtherNet/IP and Profinet encapsulated with Ethernet frames to send and receive supervisory and control information between industrial devices and systems.

    All of these applications are designed to work over Ethernet-based twisted-pair copper or fiber cables and connectors that have been hardened to stand up to factors such as vibration, dust and liquid ingress, chemicals and electromagnetic interference found in the industrial environment. The ability to maintain operations and productivity via Industrial Ethernet is only as good as this underlying cabling infrastructure, but even after that infrastructure has been installed, tested and apparently doing its job, problems can arise that bring industrial operations to a screeching halt.

    Whether caused by accidental damage and contaminants to cables and connectors in the harsh industrial environment, interference from new machinery, or changes to infrastructure that went awry due to the wrong components or improper installation, plant managers and operations technology (OT) staff need to act fast to locate and fix the problem to keep machines in production. With more than half of Industrial Ethernet problems traced to the cabling infrastructure, knowing the most effective way to troubleshoot can mean the difference between an hour of unplanned downtime versus days that could wreak havoc on production standards and translate into millions of dollars of lost revenue.

    The good news is that there are plenty of simple, inexpensive troubleshooting tools available that can help you quickly identify and locate copper and fiber cabling problems to expedite repair and reduce costly unplanned downtime.

    Reply
14. May 17, 2021 at 12:40 pm

    Tomi Engdahl says:

    How time-sensitive networking is making Ethernet deterministic
    Time-sensitive networking (TSN) is designed to make Ethernet deterministic by design and improve synchronicity and overall communication among devices.
    https://www.controleng.com/articles/how-time-sensitive-networking-is-making-ethernet-deterministic/?oly_enc_id=0462E3054934E2U

    Learning Objectives
    Time-sensitive networking (TSN) is designed to make Ethernet more deterministic.
    Profinet over TSN is designed for controller to device communication.
    Industrial trends such as Industry 4.0 and the Industrial Internet of Things (IIoT) lead to an increase in network traffic in ever-growing converged networks.

    Practical and value-based Industry 4.0
    Industry 4.0 might seem daunting and expensive, but manufacturers can make it practical without getting bogged down in details.
    https://www.controleng.com/articles/practical-and-value-based-industry-4-0/?oly_enc_id=0462E3054934E2U

    Reply
15. May 19, 2021 at 6:25 am

    Tomi Engdahl says:

    DIY | How to Check all ports UP / DOWN using Excel & SNMP
    https://www.youtube.com/watch?v=tUdJjo91e0Q

    how to check the status of all ports of network devices at the same time by Microsoft Excel

    MIB Browser
    https://www.ireasoning.com/mibbrowser.shtml

    iReasoning MIB browser is a powerful and easy-to-use tool powered by iReasoning SNMP API . MIB browser is an indispensable tool for engineers to manage SNMP enabled network devices and applications. It allows users to load standard, proprietary MIBs, and even some mal-formed MIBs. It also allows them to issue SNMP requests to retrieve agent’s data, or make changes to the agent. A built-in trap receiver can receive and process SNMP traps according to its rule engine.

    Reply
16. May 19, 2021 at 12:44 pm

    Tomi Engdahl says:

    Technical Challenges in Building Repeatable Wi-Fi Testing
    https://www.eetimes.com/technical-challenges-in-building-repeatable-wi-fi-testing/

    Wi-Fi testing can present engineers with any number of challenges. With the Broadband Forum’s TR-398 Issue 2 testing, the primary focus of the work is around testing the access point (AP) devices under test (DUT) since they would be deployed in the field. This approach is taken to allow results and measurements to better correlate with how the DUT will perform in the field. In this testing scenario, creating a stable, well-defined, and controlled RF test environment is critical.

    In the test setup we use at the University of New Hampshire InterOperability Lab (UNH-IOL), we control the RF environment of the DUT inside a semi-anechoic faraday chamber. The setup has equally important characteristics. First, the typical role of the faraday chamber is to prevent transmission of RF signals from inside to out of the chamber and vice versa. Second, the construction of the chamber with a radio absorbent material (RAM) lining helps to greatly reduce the reflection of the RF signals transmitted by the DUT. Added into the chamber is a number of near-field antennas, establishing the RF link with the DUT and the test setup. The semi-anechoic nature of the chamber ensures the signals captured by the antennas are the direct path (non-reflected) signal from the DUT. The same is also true in the reverse, with signals transmitted from the near field antenna also not being reflected inside the chamber.

    Reply
17. May 25, 2021 at 10:52 am

    Tomi Engdahl says:

    Yes, the optics in a fiber will still keep the light where it’s supposed to be even when it’s soaking wet.
    Also, in submarine cables it was found that fiber under pressure will absorb hydrogen from the water and the internal attenuation of the glass will shoot up.
    Source: https://www.quora.com/If-a-fiber-optic-cable-is-filled-with-water-will-it-still-work
    Water damage to fiber optic cables results in high attenuation, and degradation of the data signal.
    Source: https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.cablenetsystems.com/files/What_Happens_When_Indoor.pdf&ved=2ahUKEwjayNbq0OTwAhVMl4sKHXDdCE0QFjAEegQIGBAF&usg=AOvVaw24HKUVpm2ygBcY-U6d6hAT

    Reply
18. May 26, 2021 at 4:38 am

    Tomi Engdahl says:

    Tech giants fight ‘cloud wars’ deep in the ocean
    https://www.bbc.com/news/business-57070318

    It is easy to overlook that our access to the internet relies on thousands of miles of cable, crossing the world’s oceans. They provide the plumbing for the internet – 98% of all international internet traffic travels through them.

    Some connect neighbouring countries, such as the 131km (80 mile) CeltixConnect cable between Ireland and the UK. Others like the Asian-America Gateway cable, stretch for 20,000km and link continents.

    According to Daniel Sousa, managing director of manufacturing operations at SubCom, one challenge is that “the entire cable systems need to be manufactured and tested as a complete system”.

    Cables are tested ashore before being loaded on to ships, a process which can take around two weeks, says Orange Marine’s chief executive Didier Dillard.

    The company operates six cable ships, with one vessel, the René Descartes, able to lay up to 6,000km of cable.

    TeleGeography estimates that content providers – Google, Facebook, Amazon and Microsoft – have spent over $1.5bn (£1bn) on cable construction in the last five years.

    The simple reason is that they have more demand for bandwidth than anyone else, says Alan Mauldin.

    Cloud computing has become a huge business as firms have moved their computing and digital storage needs to services like Amazon’s AWS and Azure from Microsoft.

    Reply
19. May 26, 2021 at 7:42 am

    Tomi Engdahl says:

    Don’t Ignore the Hazards Associated with Fiber Optics
    https://www.ecmweb.com/content/article/20888616/dont-ignore-the-hazards-associated-with-fiber-optics

    Understanding the safety hazards that go with fiber optic cable is critical for those who install or maintain fiber optic systems. As electrical professionals, most of us take fiber optic (FO) safety for granted. Since fiber optic cable carries no electricity, we don’t worry about electrocution. Similarly, we don’t think about personal or property damage due to fire because it isn’t a source of heat

    The power levels and wavelengths found in common fiber systems range from 50 nanowatts (nW) to 10 milliwatts (mW), as shown in the table, below. While this may not sound like a lot of wattage, keep in mind this light can potentially pump through a fiber that’s only 9 millionths of a meter (microns) in diameter. Even at these low levels of power, that’s a fairly high level of watts per square centimeter.

    Dangerous situations arise when untrained people pick up a live fiber, and look directly into it. They see no light. Therefore, they assume there’s no danger. However, such unsuspecting people can end up with a burned retina in a very short time.

    Do not confuse looking into a live fiber with performing continuity checks. We call one of the better testing tools available today a visual tracer. Essentially, a visual tracer is a visible light you shine down the fiber.

    You can also purchase a special film card to identify live fibers by eye. This small card, which costs about $10), converts the infrared light to visible light. By using it, you can tell quickly and easily whether a fiber is live or not.

    The odds of going blind by looking into the broken end of an optical fiber are virtually nil, since the broken surface tends to scatter the light coming through it. However, it is possible for you to suffer injury by mishandling polished optical fibers, but only under certain circumstances, including: 1. The light source must be high-powered. Only the more powerful lasers are strong enough to cause injury. For example, some Cable TV lasers are powerful enough to do damage. 2. The beam of light exiting the fiber must be narrow. Do you remember the old trick of starting a fire with sunlight and a magnifying glass? Just as in that case, the light from a fiber must be very tightly focused to cause harm.

    Microscopic glass needles. A more serious hazard of optical fiber work is the fibers themselves. Fibers are pieces of glass. And like all glass, they can cause injury.

    Because of this, you need to handle fiber with care. First of all, you must be very careful when handling open fibers; that is fibers not contained in a cable. (Modern optical fiber cables are very safe, and pose no danger to you. It is when the cables open that hazards arise.) If you were to accidentally jab yourself with one of these open fibers, you could easily end up with a painful sliver. What’s worse is this sliver may not be visible! Remember: These slivers are made of transparent glass and can be very difficult to see.

    You’ll be surprised to know that jabbing yourself with a fiber is not the most hazardous situation. The real danger is when fibers are stripped, trimmed, and cut. These operations result in short, nearly microscopic pieces of glass lying around a work area. These are short, thin, invisible needles. If they’re left lying around, someone will inevitably end up touching or handling them. As sharp and thin as these glass shards are, they can easily penetrate your skin. And unlike a wood sliver, these glass slivers will not degrade inside your skin.

    These cut pieces of fiber are very dangerous. If they were to end up in your lunch, they could cause internal bleeding and conceivably death.

    To avoid this problem, you should make generous use of masking tape (or any other type of tape) to catch the waste fiber pieces. Some technicians wrap the tape around a few fingers, sticky side out. This catches the fibers as soon as they are cut. You should also frequently blot the entire work area with tape to pick up stray pieces.

    Reply
20. May 26, 2021 at 7:46 am

    Tomi Engdahl says:

    Use caution when working with fiber
    https://www.cablinginstall.com/cable/article/16467818/use-caution-when-working-with-fiber

    Cabling installation professionals face safety hazards when working with both copper and fiber-optic cables, but if you ask them which cable provokes more cautious handling, they are likely to say copper because of the electricity it carries. Since optical fiber carries light, it is assumed to be the safer medium. This belief may be misplaced, however. While optical fiber doesn`t carry electricity, it does transmit light, which, in some instances, can damage the eye. The glass fiber itself also

    Cabling installation professionals face safety hazards when working with both copper and fiber-optic cables, but if you ask them which cable provokes more cautious handling, they are likely to say copper because of the electricity it carries. Since optical fiber carries light, it is assumed to be the safer medium. This belief may be misplaced, however. While optical fiber doesn`t carry electricity, it does transmit light, which, in some instances, can damage the eye. The glass fiber itself also poses a danger, potentially becoming embedded in or under the skin.

    In recent years, common safety concerns have been addressed in most cabling industry training programs and materials, but fiber-optic safety still takes a backseat to other safety concerns, according to Larry Johnson, president of The Light Brigade (Kent, WA), a fiber-optic training company. “The industry downplays fiber-optic safety. It`s not seen as a major issue,” Johnson says.

    To terminate fiber-optic cable, whether for connectorization or splicing, the installer usually strips back the cable`s jacket and buffer to access the glass fiber and its cladding. Once stripped, the fiber is inserted into the connector. A cleave tool is used to produce a smooth endface and prepare the fiber for insertion into a splice or for polishing.

    But what happens to the piece of glass that has been cleaved? The cleaved fiber may fall where it will–on the top of the table where the job is being done, at the bottom of the raised floor, or maybe into a cup of coffee that is close by. The scraps may even be brushed into a nearby garbage can. Then what happens if someone rests his or her hand on top of that fiber scrap? The glass is transparent and the scrap is probably small, so unless the person is the one who did the terminating, he or she may not know the hazard is there.

    By comparison, a small wood splinter may not pose a threat to most people, but a glass sliver could. The nearly invisible sliver may be impossible to locate once it breaks the skin, so in many cases, the splinter cannot be removed until the area becomes inflamed and infected.

    While the fiber-scrap trash can is convenient, many installers still choose to use an old standby for catching the scraps–double-sided tape. The scrap-laden tape can be tossed into the trash can. However, this system has its own problems. A janitor emptying the garbage later could get a splinter and not know what it is.

    “The key point is that the contractor has to be responsible for his or her debris,” Johnson notes. “If he leaves it in the garbage can or drops it in a raised floor, the person coming in later is going to pay the penalty.”

    Johnson suggests that contractors police themselves. “You are dealing with a liability issue, and if you are the end-user, you need to protect yourself,” he adds. “The end-user may even want to write up a section on proper fiber disposal in the contract.”

    With plastic optical fiber becoming better known, questions about its safety may also arise, but this concern is not entirely warranted, says Johnson. The core of plastic optical fiber is too large to be hazardous, and the fiber is not as sharp as glass.

    “With plastic, you don`t see the fracturing of the end like you do with glass,” Johnson states. “A glass-fiber end is very similar to a hypodermic needle. It doesn`t take much for it to break the skin.”

    Lasers used in telecommunications tend to fall into one of two classifications–Class I or Class II–says Curtis Smith, an applications engineer with test-equipment manufacturer Tektronix Inc. (Beaverton, OR).

    “Most telecommunications transmitters and optical time-domain reflectometers (otdrs) fall into the Class I classification,” adds Smith. “These lasers are considered to be inherently safe. The reality is that if you are looking into a Class I laser you are more in danger of poking your eye out with the end of the fiber than of being hurt from the light.”

    Class II lasers are more powerful transmitters. Visual fault finders, for instance, put a strong signal on the fiber and fall into this category. The signal they produce is so powerful that, if there is a break in the fiber, the light is visible through the jacket. While otdrs are considered Class I devices, some do have a visual fault-finder port.

    Class II transmitters are not usually found in local area networks (lans) or telephone-system environments. Smith says, “The high-powered transmitters are mainly used in cable-TV systems. This is where you have a very strong transmitter that can send signals through 1 to 12 splitters. The signal must be strong enough to reach the 12 locations.”

    An important difference between these two classifications is that Class I lasers do not require any specific warning label. On the other hand, Class II devices must be identified with a warning label, which is usually printed in red and notes that the device produces hazardous light.

    Commonly found in the lan environment are leds. Because these light sources are typically used in short- distance environments involving multimode fiber, they don`t pose the risk that lasers do. Lasers are usually used with singlemode fiber.

    “There have certainly been advances in optical amplifiers, and the receivers have become more sensitive to smaller power levels,” says Tektronix`s Smith. “Today`s systems are using what is there more efficiently.”

    One area that could increase the power being transmitted is wavelength-division multiplexing (wdm). Smith explains, “If you have an older system that is producing a wavelength of light at 1550 nm, which is typical of longer-haul systems, you have one transmitter and one receiver. The wdm system is going to use 1550 nm, as well as 1560 and 1540 nm, and so forth. So now you`ve put four-, six-, and eight-transmitter lasers onto that fiber.”

    He adds that individually these transmitters are Class I lasers because they are sending at 1550 nm. “But now that you`ve put up to six times the amount of power on that fiber, you are going to get an overall higher power level because you have several wavelengths on a fiber as opposed to one. Unfortunately, the classification covers the laser device, not the system.”

    Overall, Smith suggests that people use common sense. “If you don`t know what`s going into the other end of the line, don`t look at the fiber. Be careful, but you don`t need to be paranoid.”

    Reply
21. May 27, 2021 at 3:20 pm

    Tomi Engdahl says:

    https://etn.fi/index.php/13-news/12204-nokian-laitteilla-maailman-nopein-kuituverkko

    Nokia ja hollantilainen Proximus käynnistivät maailman nopeimman kuituverkon eilen Antwerpenissä. Proximus-verkossa olevien olemassa olevien kuitu- ja Nokia-laitteiden kautta toimiva kaikkien aikojen ensimmäinen 25G PON -verkkoyhteys yhdistää Havenhuisin rakennuksen Antwerpenin satamaan Proximus-keskustoimistoon keskellä kaupunkia.

    Verkon nopeus ylitti 20 gigabittiä sekunnissa ja teki siitä samalla nopeimman kuituverkon maailmassa.

    Reply
22. May 27, 2021 at 8:50 pm

    Tomi Engdahl says:

    How to Test Your Internet Speed Bidirectionally from Command Line Using ‘Speedtest-CLI’ Tool

    https://www.tecmint.com/check-internet-speed-from-command-line-in-linux/

    Reply
23. May 28, 2021 at 6:01 pm

    Tomi Engdahl says:

    https://corporate.comcast.com/press/releases/comcast-conducts-ull-duplex-chip-multi-gigabit-symmetrical-speeds

    Reply
24. May 28, 2021 at 7:22 pm

    Tomi Engdahl says:

    https://www.quora.com/If-a-fiber-optic-cable-is-filled-with-water-will-it-still-work

    Reply
25. May 28, 2021 at 7:44 pm

    Tomi Engdahl says:

    https://hackaday.com/2021/05/22/irc-will-never-die/

    Reply
26. June 2, 2021 at 2:27 pm

    Tomi Engdahl says:

    Acoustic signals are the current communication medium of choice for underwater sensors, but that could change with new research into using light to transmit both data and power

    Taking Underwater Communications And Power to New Depths With Light
    https://spectrum.ieee.org/tech-talk/sensors/remote-sensing/new-approach-could-take-underwater-communication-using-light-to-new-depths

    a new study published May 4 in IEEE Transactions on Wireless Communications, researchers have identified a new way to boost the transfer of power and data to devices underwater using light.

    Currently the most common approach for remotely transmitting signals underwater is via sound waves, which easily travel long distances through the watery depths. However, sound cannot carry nearly as much data as light can.

    “Visible light communication can provide data rates at several orders of magnitude beyond the capabilities of traditional acoustic techniques and is particularly suited for emerging bandwidth-hungry underwater applications,” explains Murat Uysal, a professor with the Department of Electrical and Electronics Engineering at Ozyegin University, in Turkey.

    He also notes that powering sensors and other devices underwater is another challenge, as replacing batteries in marine environments can be particularly difficult. Conveniently, any device that uses a solar panel to receive data via light signals could also be used to harvest energy simultaneously. In such a scenario, an autonomous underwater vehicle passing by a sensor could use a laser to both collect data and transfer power to the device.

    Currently, the most effective method to do this is through an approach in which the power derived from the light signal is separated into Alternating Current (AC) and Direct Current (DC), whereby the AC signal is used to transmit data and the DC signal is used a power source. This is called the AC-DC separation (ADS) method.

    However, some scientists, including Uysal’s team, have been trying to build upon a different approach that strategically switches between energy harvesting and data transfer as needed to optimize performance. This approach is called simultaneous lightwave information and power transfer (SLIPT).

    Uysal notes that this allows their SLIPT method to “significantly outperform” the traditional ADS method.

    “The feasibility of wireless power was already successfully demonstrated in underwater environments [using light], despite the fact that seawater conductivity, temperature, pressure, water currents, and biofouling phenomenon impose additional challenges,” says Uysal.

    Reply
27. June 2, 2021 at 2:42 pm

    Tomi Engdahl says:

    https://www.uusiteknologia.fi/2021/06/02/nettisatelliitit-jo-loppuvuodesta-kayttoon/

    Matalan kiertoradan satelliittipalveluiden tietoliikenneyhteyksillä voi olla potentiaalia myös turvallisuus- ja viranomaiskäytössä. Suomen valtion omistaman Erillisverkot järjesti viime viikolla verkkoseminaarin OneWeb-yhtiön ratkaisusta, joka aikoo aloittaa palvelut pohjoisella alueella loppuvuodesta ja maailmanlaajuisesti vuoden 2022 aikana.

    Reply
28. June 4, 2021 at 8:36 am

    Tomi Engdahl says:

    Fiber vs. Copper; What do we really need?
    https://www.youtube.com/watch?v=CwZdur1Pi3M

    Fiber optics. A DeLIGHTful technology. Ooh that’s a groaner. Well, why don’t we see them around more often? Let’s find out!

    Reply
29. June 5, 2021 at 5:38 pm

    Tomi Engdahl says:

    By year’s end, drivers in the largest U.S. metro areas may unwittingly rumble over the tenuous strands of a new and potentially revolutionary network: a “quantum internet.”

    New internet woven from ‘spooky’ quantum links could supercharge science and commerce
    https://www.sciencemag.org/news/2021/06/new-internet-woven-spooky-quantum-links-could-supercharge-science-and-commerce?utm_campaign=SciMag&utm_source=JHubbard&utm_medium=Facebook

    A beam of ethereal blue laser light enters a specialized crystal. There it turns red, a sign that each photon has split into a pair with lower energies—and a mysterious connection. The particles are now quantum mechanically “entangled,” linked like identical twins who know each other’s thoughts despite living in distant cities. The photons zip through a tangle of fibers, then ever so gently deposit the information they encode into waiting clouds of atoms.

    The transmogrifications are “a little bit like magic,” exults Eden Figueroa, a physicist at Stony Brook University. He and colleagues have concocted the setup on a few laboratory benches cluttered with lenses and mirrors. But they have a much bigger canvas in mind.

    By year’s end, drivers in the largest U.S. metro areas—including, largely thanks to Figueroa, the suburbs of New York City—may unwittingly rumble over the tenuous strands of a new and potentially revolutionary network: a “quantum internet” stitched together by entangled photons like those in Figueroa’s lab.

    A beam of ethereal blue laser light enters a specialized crystal. There it turns red, a sign that each photon has split into a pair with lower energies—and a mysterious connection. The particles are now quantum mechanically “entangled,” linked like identical twins who know each other’s thoughts despite living in distant cities. The photons zip through a tangle of fibers, then ever so gently deposit the information they encode into waiting clouds of atoms.

    The transmogrifications are “a little bit like magic,” exults Eden Figueroa, a physicist at Stony Brook University. He and colleagues have concocted the setup on a few laboratory benches cluttered with lenses and mirrors. But they have a much bigger canvas in mind.

    By year’s end, drivers in the largest U.S. metro areas—including, largely thanks to Figueroa, the suburbs of New York City—may unwittingly rumble over the tenuous strands of a new and potentially revolutionary network: a “quantum internet” stitched together by entangled photons like those in Figueroa’s lab.

    Putting these fragile links into the warm, buzzing world will not be easy, however. Most strands that exist today can send entangled photons to receivers just tens of kilometers apart. And the quantum links are fleeting, destroyed as the photons are received and measured. Researchers dream of sustaining entanglement indefinitely, using streams of photons to weave lasting quantum connections across the globe.

    For that, they will need the quantum equivalent of optical repeaters

    On the scale of 5 to 10 years … we’ll have continental-scale network prototypes.

    Mikhail Lukin, Harvard University

    Reply
30. June 8, 2021 at 5:47 am

    Tomi Engdahl says:

    $1 billion piracy ruling could force ISPs to disconnect more Internet users
    Increased account terminations would punish “innocent” users, groups tell court.
    https://arstechnica.com/tech-policy/2021/06/1-billion-piracy-ruling-could-force-isps-to-disconnect-more-internet-users/

    A billion-dollar judgment in a piracy lawsuit involving a major Internet service provider could force ISPs to terminate more customer accounts and “punish the innocent and guilty alike,” advocacy groups have warned. Urging an appeals court to overturn the ruling, the groups wrote that “upholding this verdict would result in innocent and vulnerable users losing essential Internet access.”

    These concerns were raised in a court filing last week by the Electronic Frontier Foundation (EFF), the Center For Democracy and Technology, the American Library Association, the Association of College And Research Libraries, the Association of Research Libraries, and Public Knowledge. The groups’ filing was made to the US Court of Appeals for the 4th Circuit in support of an appeal seeking to overturn a ruling in a case launched by record labels against Cox Communications.

    “In going after Internet service providers for the actions of just a few of their users, Sony Music, other major record labels, and music publishing companies have found a way to cut people off of the Internet based on mere accusations of copyright infringement,” the EFF wrote in a blog post announcing the filing.

    If Not Overturned, a Bad Copyright Decision Will Lead Many Americans to Lose Internet Access
    https://www.eff.org/deeplinks/2021/06/if-not-overturned-bad-copyright-decision-will-lead-many-americans-lose-internet

    In going after internet service providers (ISPs) for the actions of just a few of their users, Sony Music, other major record labels, and music publishing companies have found a way to cut people off of the internet based on mere accusations of copyright infringement. When these music companies sued Cox Communications, an ISP, the court got the law wrong. It effectively decided that the only way for an ISP to avoid being liable for infringement by its users is to terminate a household or business’s account after a small number of accusations—perhaps only two. The court also allowed a damages formula that can lead to nearly unlimited damages, with no relationship to any actual harm suffered. If not overturned, this decision will lead to an untold number of people losing vital internet access as ISPs start to cut off more and more customers to avoid massive damages.

    Reply
31. June 8, 2021 at 12:27 pm

    Tomi Engdahl says:

    How MoCA Made My Home Network Faster Than Mesh Wifi
    https://lifehacker.com/how-moca-made-my-home-network-faster-than-mesh-wifi-1846927535?utm_campaign=Lifehacker&utm_content=1621524007&utm_medium=SocialMarketing&utm_source=facebook

    I love fussing with wifi, but when I’m building the backbone of my network in a new location—a house, apartment, or wherever—I tend to go wired as much as I can. Wireless bridges and tri-band mesh/extender setups are great and convenient, but I always appreciate the stability and speed of an Ethernet cable.

    When I recently offered to help my friends set up their house with a wired backbone, I came across a fun problem: No Ethernet connections in any of their rooms. That didn’t surprise me very much, as that tends to be a more modern convenience that older houses simply don’t have.

    The ingenious solution to this problem? MoCA, or “Multimedia over Coaxial.” I’ve known about the technology for a long time, but never had the time (or need) to play with it until now. My friends’ house was wired with coaxial cables in every room, which made this an ideal solution. I could just use MoCA instead of Ethernet—MoCA 2.0, technically, which gives up to a full gigabit worth of speed and should be more than adequate (even if it doesn’t run that fast) for my friends’ ~400Mbps internet plan.

    I got my hands on a two-pack of TrendNET TMO-311C2K adapters and got to work, which took all of five minutes because I was acting the fool. It should come as little surprise that plugging in the MoCA adapters to various coaxial ports around the house achieved absolutely nothing. No signal.

    Part of that stems from the very nature of running cable around one’s house, period.

    I wasn’t too surprised to find that many of the coaxial cables around my friends’ house simply weren’t connected to anything. I was eventually able to confirm this by tracing the wires to the outside of the house, where I found where all the disconnected cables terminated.

    I also grabbed a MoCA PoE filter and a single high-quality splitter to give the house the best possible signal it could. And, as you can probably determine, my goal was to use MoCA to connect a downstairs room and an upstairs room with coaxial-based Ethernet. Since the upstairs room is where the house’s cable modem sat, I’d be able to:

    Set up a wireless access point downstairs. Connect it via MoCA to the upstairs router to create two wifi “bubbles” with a speedy wired backbone.
    Also connect the upstairs router to the cable modem.
    Connect the cable modem to the upstairs MoCA adapter, which the router would also be connected to (via Ethernet).

    In other words, the cable connection would be doing all the heavy lifting for data around the house, and I’d be able to connect both coaxial-based devices (the cable modem) and Ethernet-based devices (everything else) thanks to the MoCA adapters.

    Easy as pie. And I’m not just being glib; once I connected the PoE filter and hooked up the splitter, joining both rooms’ cable connections, the MoCA adapters lit up to let me know that they could see each other. Five minutes later, my network was up and running, and it couldn’t have been any easier. Both floors of the house now had wifi, and was a much speedier solution than the mesh setup my friends were dealing with before.

    Me? I’m going to add MoCA to the list of tools in my networking arsenal. While I used to have a mindset of, “We’ll just string Ethernet cable around everywhere and that’ll look great,” it’s a lot cleaner to be able to connect a little $50 adapter to a room’s existing coaxial connection and call it a day. Pricier, sure, but now I don’t have to fuss with cable management all around the house. I wonder what I’ll do with this 75-foot Cat6 Ethernet cable I’ve been lugging around the past few years.

    Reply
32. June 10, 2021 at 11:40 am

    Tomi Engdahl says:

    https://www.bleepingcomputer.com/news/security/arin-will-take-down-its-rpki-for-30-minutes-to-test-your-bgp-routes/

    Reply
33. June 14, 2021 at 6:08 am

    Tomi Engdahl says:

    https://m.facebook.com/story.php?story_fbid=4021257821295535&id=153759051378784

    - Nyt on meneillään fotoniikan ja biotekniikan vuosisata, sanoo Fotoniikan instituutin johtaja, professori Jyrki Saarinen.

    Mitä muutoksia elämäämme on tulossa jo lähitulevaisuudessa?

    Lue lisää aiheesta ja katso tallenne Tiedekahvilastamme! https://bit.ly/34wQM6a

    #fotoniikka #biotekniikka #valo #energia #ilmasto #terveys #tietoliikenne #autot #ympäristö #AR #Dispelix #tulevaisuus Fysiikan ja matematiikan laitos, Itä-Suomen yliopisto, Joensuu #PREIN Institute of Photonics UEF Ympäristö- ja biotieteet / Environmental and Biological Sciences Sovelletun fysiikan laitos, Itä-Suomen yliopisto

    Reply
34. June 14, 2021 at 8:06 am

    Tomi Engdahl says:

    Researchers create an ‘un-hackable’ quantum network over hundreds of kilometers using optical fiber https://www.zdnet.com/article/researchers-created-an-un-hackable-quantum-network-over-hundreds-of-kilometers-using-optical-fiber/
    Researchers from Toshiba have successfully sent quantum information over 600-kilometer-long optical fibers, creating a new distance record and paving the way for large-scale quantum networks that could be used to exchange information securely between cities and even countries.

    Reply
35. June 15, 2021 at 11:12 am

    Tomi Engdahl says:

    https://etn.fi/index.php/13-news/12288-huawei-maailmanennatykseen-kuidussa-yhdella-aallonpituudella

    Huawei kertoo saaneensa päätökseen optisten yhteyksien DWDM-kenttäkokeen, jossa rikottiin vanhat ennätykset. Yhtiö siirsi yhdellä aallonpituudella dataa standardissa G.652-kuitukaapelissa 96,5 kilometrin päähän 1,66 terabitin linjanopeudella. Käytössä oli vain standardi EDFA-vahvistus.

    Kenttäkoe tehtiin yhdessä eurooppalaisen suuren operaattorin kanssa. Kokeessa dataa lähetettiin yhteensä 34 kanavalla kokonaiskapasiteetin ollessa 56 terabittiä sekunnissa. Spektritehokkuudeksi tuli näin yli 11 bittiä sekunnissa hertsiä kohti.

    Reply
36. June 21, 2021 at 3:12 pm

    Tomi Engdahl says:

    SALT LAKE CITY
    4 Terabit Internet?! Fiber Company Tour!
    https://www.youtube.com/watch?v=2e9DNwInTE4

    Snazzy Labs gets an exclusive tour inside a fiber internet company’s operations and learns how the internet works.
    Learn more about the largest open access network in the country here: https://www.utopiafiber.com/
    Sponsored by UTOPIA Fiber

    Reply
37. June 23, 2021 at 4:06 am

    Tomi Engdahl says:

    To spirit the money away, the gang behind the heist would use fake bank accounts, charities, casinos and a wide network of accomplices.

    Fiber Optic Cables Could Shake Up Our Understanding of Deep-Sea Quakes
    https://spectrum.ieee.org/tech-talk/telecom/internet/fiber-optic-cables-could-shake-up-our-understanding-of-deepsea-quakes

    There’s a lot we don’t know about the ocean floor, thanks to crushing pressures and perpetual darkness. But there are still repercussions from what happens down there. Deep sea earthquakes, for example, can result in devastating tsunamis. So it would be nice to keep an eye on the ocean floor.

    Fortunately, despite the remote and punishing environment, we already have a plethora of potential eyes on the bottom of the sea. There are around 400 fiber optic cables spanning the oceans. These cables are already the backbone of the global Internet—what if they could be the backbone of deep-sea monitoring and research efforts as well?

    That’s precisely what a group of researchers from the California Institute of Technology, Google, and the University of L’Aquila in Italy have been working on. In a paper published in Optica, the group outlines a technique for using perturbations in the polarization of signals traveling through the fiber to detect undersea earthquakes and sea waves, like tsunamis.

    Reply
38. June 23, 2021 at 4:07 am

    Tomi Engdahl says:

    The first thing the researchers discovered is that the Curie cable’s baseline level of polarization perturbations is remarkably stable. In other words, as the optical signals travel along the length of the cable, the polarization of those signals does not change much due to the cable itself. “The fact that the transmission system is so stable, it’s the reason why we could use it to measure [other vibrations],” says Mecozzi. “Only strong perturbations by earthquakes are able to affect the polarization in a way we can measure.”

    The researchers found that by taking data readily available from the receivers at the ends of the Curie cable, they could hunt for the deviations from baseline levels that hinted at an earthquake or powerful underwater waves.

    https://spectrum.ieee.org/tech-talk/telecom/internet/fiber-optic-cables-could-shake-up-our-understanding-of-deepsea-quakes

    Reply
39. June 23, 2021 at 4:10 am

    Tomi Engdahl says:

    “Only strong perturbations by earthquakes are able to affect the polarization in a way we can measure.”

    A test with Google’s Curie cable suggests that the undersea fiber optic cable network that spans the world’s oceans could act as an early-warning system for devastating tsunamis

    https://www.facebook.com/48576411181/posts/10159406277156182/

    Reply
40. June 24, 2021 at 8:52 am

    Tomi Engdahl says:

    Magneto Era (1876-1900)
    https://www.youtube.com/watch?v=SLCnbgCbto4

    Reply
41. June 28, 2021 at 3:16 pm

    Tomi Engdahl says:

    https://www.edn.com/is-it-possible-to-measure-isi-at-high-data-rates/

    Reply
42. June 30, 2021 at 10:57 am

    Tomi Engdahl says:

    Just How Did 1500 Bytes Become The MTU Of The Internet?
    https://hackaday.com/2021/06/29/just-how-did-1500-bytes-become-the-mtu-of-the-internet/

    [Benjojo] got interested in where the magic number of 1,500 bytes came from, and shared some background on just how and why it seems to have come to be. In a nutshell, the maximum transmission unit (MTU) limits the maximum amount of data that can be transmitted in a single network-layer transaction, but 1,500 is kind of a strange number in binary. For the average Internet user, this under the hood stuff doesn’t really affect one’s ability to send data, but it has an impact from a network management point of view. Just where did this number come from, and why does it matter?

    [Benjojo] looks at a year’s worth of data from a major Internet traffic exchange and shows, with the help of several graphs, that being stuck with a 1,500 byte MTU upper limit has real impact on modern network efficiency and bandwidth usage, because bandwidth spent on packet headers adds up rapidly when roughly 20% of all packets are topping out the 1,500 byte limit.

    https://blog.benjojo.co.uk/post/why-is-ethernet-mtu-1500

    Reply
43. June 30, 2021 at 11:16 am

    Tomi Engdahl says:

    Shara Tibken / CNET:
    Studies have found that certain neighborhoods across the US that were redlined in the past are the same areas without fast home internet service today — Communities that couldn’t get mortgage loans in the 1940s are the same areas without fast home internet service today. There’s no easy fix.

    The broadband gap’s dirty secret: Redlining still exists in digital form
    https://www.cnet.com/features/the-broadband-gaps-dirty-secret-redlining-still-exists-in-digital-form/

    Communities that couldn’t get mortgage loans in the 1940s are the same areas without fast home internet service today. There’s no easy fix.

    “What we found out with unlimited data is it’s still limited because they slow your internet down,” Wilson said. “If my daughter’s online, doing school, it’s terrible waiting all that time.”
    broadband-promo-bug-update.png
    Robert Rodriguez/CNET

    The gap in broadband coverage in a poorer neighborhood is effectively a digital form of redlining, a now-banned practice that denied service based on race. In the 1930s, banks started developing maps to withhold loans for high-risk, “undesirable inhabitant types,” who were almost always poor people of color. The redlining extended to a refusal to insure residents in low-income neighborhoods, denial of health care and decisions not to build essential facilities like supermarkets. Even Amazon has been accused of not serving poor, predominantly Black neighborhoods with its Prime same-day shipping plan.

    The decades of redlining represent a form of systematic racism that has denied generations of Black communities the kind of opportunities many other Americans enjoy. And the fear is it’s happening again with broadband internet service. Big providers, when deciding where to invest the money to upgrade their networks, often focus on wealthier parts of cities and shun low-income communities. Fiber connections are expensive, and ISPs are hesitant to expand unless they expect a return on their investment. As a result, poorer communities often have no internet or are stuck with slow, legacy networks that can’t meet today’s demands — even though they usually pay as much as their wealthier neighbors who have gigabit fiber connections.

    Digital redlining isn’t illegal since there aren’t regulations that dictate where broadband providers build their networks.

    Reply
44. July 1, 2021 at 10:00 am

    Tomi Engdahl says:

    SpaceX is losing money on its Starlink terminals, but sees lower costs ahead
    https://techcrunch.com/2021/06/29/spacex-is-losing-money-on-its-starlink-terminals-but-sees-lower-costs-ahead/?tpcc=ECFB2021

    It may be a little while longer until Starlink hits profitability. The SpaceX project, which aims to deliver global high-speed broadband via a satellite network, sells its beta kits to customers for around $500 dollars despite it costing much more to produce them, CEO Elon Musk said in an interview Tuesday.

    The kit includes a user terminal, a kind of dish, that connects the customer to the satellites and enables broadband access. “To be totally frank, we are losing money on that terminal right now,” he said. “That terminal costs us more than $1,000, so obviously I’m subsidizing the cost of the terminal.” He went on to add that SpaceX is working on a next-gen terminal capable of providing the same capability, but at a lower cost to make.

    Reply
45. July 6, 2021 at 9:11 am

    Tomi Engdahl says:

    Ensimmäiset 10G:n internetyhteydet asennettu – Salolainen Markus Järvinen ensimmäisten joukossa
    https://www.lounea.fi/ensimmaiset-10gn-internetyhteydet-asennettu-salolainen-markus-jarvinen-ensimmaisten-joukossa

    Reply
46. July 6, 2021 at 2:56 pm

    Tomi Engdahl says:

    Researchers create fiber network that operates at 99.7% speed of light, smashes speed and latency records
    https://www.extremetech.com/computing/151498-researchers-create-fiber-network-that-operates-at-99-7-speed-of-light-smashes-speed-and-latency-records

    Reply
47. July 7, 2021 at 1:34 pm

    Tomi Engdahl says:

    Terminating on a 110 Patch Panel
    https://www.youtube.com/watch?v=i5NKTI2OssQ

    This video provides a step by step approach on how to terminate twisted pair cables onto a loaded patch panel.

    Krone termination blocks
    https://www.youtube.com/watch?v=lDYuJm_EUEs

    Reply
48. July 7, 2021 at 1:35 pm

    Tomi Engdahl says:

    TELEPHONE CABLE MDF KRONE TERMINATION | PAR WIRE PUNCHING & CRIMPING
    https://www.youtube.com/watch?v=SjBu-Lw8D38

    50+50 Pair Telephone Jelly Cable Exchange MDF Krone termination
    https://www.youtube.com/watch?v=3hvN99YiLx8

    Reply
49. July 7, 2021 at 1:36 pm

    Tomi Engdahl says:

    T568A vs T568B – what’s the difference and how to test patch leads.
    https://www.youtube.com/watch?v=z7CQlBe48Vs

    Reply
50. July 7, 2021 at 4:00 pm

    Tomi Engdahl says:

    https://hackaday.com/2021/07/07/starlink-terminal-unit-firmware-dumped/
    StarLink wants to avoid cost by connecting you via an array of low-orbit satellites and some users are already using the service. In Belgium, [Lennert Wouters] managed to dump the terminal’s firmware and has some interesting observations.

    Reply