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1. What is 802.11ax?

802.11ax is an IEEE draft amendment that defines modifications to the 802.11physical layer (PHY) and the medium access control (MAC) sublayer for high-efficiency operation in frequency bands between 1 GHz and 6 GHz. The technical term for an 802.11ax is High Efficiency (HE).

2. Why is 802.11ax needed?

Past amendments defined 802.11 higher data rates and wider channels but did not address efficiency. The bulk of 802.11 data frames (75-80%) are small and under 256 bytes. The result is excessive overhead at the MAC sublayer and medium contention overhead for each small frame. Higher data rates and wider channels is not the goal of 802.11ax. The goal is better and more efficient 802.11 traffic management. Another goal is to increase the average throughput 4X per user in high-density WLAN environments.

3. When will 802.11ax be an official standard?

The IEEE is currently scheduled to ratify the 802.11ax amendment in Q1 2020. The Wi-Fi Alliance has launched it’s 802.11ax certification program as Wi-Fi 6. As was done with 802.11n and 802.11ac, WLAN vendors have released 802.11ax products prior to the ratification of the amendment. As a matter of fact, Extreme Networks already has an entire family of eight 802.11ax APs with more on the way in 2020.

4. What is the Wi-Fi 6?

Recently the Wi-Fi Alliance adopted a new generational naming convention for Wi-Fi technologies. The goal is that the new naming convention will be easier to understand for the average consumer as opposed to the alphabet-soup naming used by the IEEE. Because 802.11ax technology is such a major paradigm shift from previous versions of 802.11 technology, it has been bestowed with the generational name of Wi-Fi 6. 802.11ax and Wi-Fi 6 mean the same thing, but the term Wi-Fi 6 will be more prevalent with the general population. The Wi-Fi Alliance certification for the technology is also called Wi-Fi 6.

5. Will the existing Extreme 802.11ax APs be certified for Wi-Fi 6?

Yes

6. In which frequency bands will 802.11ax radios operate?

Unlike 802.11ac, which is technology for 5 GHz only, 802.11ax radios can transmit and receive on either the 2.4 GHz or 5 GHz frequency bands. In the future, 802.11ax technology will also be available in the 6 GHz band.

7. Is 802.11ax backward compatible with older Wi-Fi radios?

Yes, 802.11ax radios will be able to communicate will legacy 802.11a/b/g/n/ac radios.  802.11ax radios will communicate with other 802.11ax radios using OFDMA and/or OFDMA. 802.11ax radios will communicate with legacy radios using OFDM or HR-DSSS.  When 802.11ax-only OFDMA conversations are occurring, RTS/CTS mechanisms will be used to defer legacy transmissions.

8. Will a customer need to upgrade their Wi-Fi clients to take advantage of 802.11ax capabilities?

802.11ax APs will not improve the performance or range of any legacy Wi-Fi clients (802.11a/b/g/n/ac). 802.11ax clients will be needed to take full advantage of 802.11ax high-efficiency capabilities such as multi-user OFDMA. While there will be no PHY improvements with legacy clients, there will be performance improvements as a result of newer hardware capabilities of the new 802.11ax APs, such as stronger CPUs, better memory handling, and other normal hardware advancements. However, as we see more 802.11ax clients mixed into the client population, the efficiency improvements gained by 802.11ax client devices will free valuable airtime for those older clients, therefore improving the overall efficiency of the system.

9. When will we see 802.11ax clients?

70% of client radios are manufactured by Broadcom. Wi-Fi 6 clients have already entered the marketplace and a Wi-Fi 6 client population explosion is coming soon. All the major chipset vendors such as Broadcom, Qualcomm, and Intel are manufacturing 2×2:2 Wi-Fi 6 radios that will find their way into smartphones, tablets, and laptops. Samsung released the Galaxy S10, the first Wi-Fi 6 smartphone, into the market in February of 2019. The Apple iPhones introduced in September 2019 also utilize Wi-Fi 6 radios. Intel has announced 100s of new Wi-Fi products by end of year. Industry analysts all agree that the Wi-Fi 6 technology growth will be fast and furious. Several analysts already are predicting 1 billion Wi-Fi 6 chipsets will ship annually by 2022

10. Does a customer need to upgrade from 802.11ac APs to 802.11ax APs? Why should a customer buy 802.11ax APs if there are not a lot of 802.11ax clients?

11ax APs will have faster processors and provide future-proofing as 802.11ax clients find their way into the marketplace.  If you are choosing between buying a new 802.11ax or 802.11ac, we would recommend going with the latest technology for the long-term return on investment.

11. What does Multi-User (MU) mean?

The term multi-user (MU) simply means that transmissions between an AP and multiple clients can occur at the same time dependent on the supported technology. However, the MU terminology can be very confusing when discussing 802.11ax. MU capabilities exist for both OFDMA and MU-MIMO. Please understand the differences as explained further in this field note.

12. What is OFDMA?

Orthogonal Frequency Division Multiple Access (OFDMA) a multi-user version of the OFDM digital modulation technology. 802.11a/g/n/ac radios currently OFDM for single-user transmissions on an 802.11 frequency. OFDMA subdivides a channel into smaller frequency allocations called resource units (RUs). By subdividing the channel, parallel transmissions of small frames to multiple users happens simultaneously. Think of OFDMA as a technology that partitions a channel into smaller sub-channels so that simultaneous multiple-user transmissions can occur. For example, a traditional 20 MHz channel might be partitioned into many as 9 smaller channels. Using OFDMA, an 802.11ax AP could simultaneously transmit small frames to nine 802.11ax clients. Intially the Wi-Fi Alliance will be testing for simultaneous transmissions of four RUs using OFDMA on both the downlink and the uplink. OFDMA is much more efficient use of the medium for smaller frames. The simultaneous transmission cuts down on excessive overhead at the MAC sublayer as well as medium contention overhead.

13. What size are the Resource Units (RUs) that will function as OFDMA sub-channels?

When subdividing a 20 MHz channel, The AP can designate 26, 52, 106, and 242 subcarrier Resource Units (RUs), which equates roughly to 2 MHz, 4 MHz, 8 MHz, and 20 MHz channels. The 802.11ax AP dictates how many RUs are used within a 20 MHz channel and different combinations can be used. For example, a Wi-Fi 6 AP could simultaneously communicate with one 802.11ax client using 8 MHz of frequency space while communicate with two other 802.11ax clients using 4 MHz sub-channels.

14. Is OFDMA downstream or upstream?

Both! The AP coordinates OFDMA transmissions both downstream and upstream using a trigger frame mechanism. For the first time in 802.11 technology, an access point can coordinate upstream client transmissions. The AP uses a trigger frame to allocate client resource units (RUs) and set transmit timing for each client.

15. Is OFDMA the same thing as MU-MIMO?

No! Do not confuse OFDMA with MU-MIMO.  OFDMA allows for multiple-user access by subdividing a channel. MU-MIMO allows for multiple-user access by using different spatial streams. Access points will send unique steams of data to multiple clients simultaneously. The 802.11ax standard also allows for the combined use of MU-MIMO and OFDMA but it is not expected to be widely implemented

16. What about MU-MIMO?  Will it be supported in 802.11ax?

Downlink MU-MIMO was introduced with Wave-2 802.11ac access points. 802.11ax will continue to support downlink MU-MIMO may also define uplink MU-MIMO. Support for uplink MU-MIMO will not be included in any of the first generation of 802.11ax radios. Real-world adoption of MU-MIMO, in general, has yet to take place.

17. Which is better, OFDMA or MU-MIMO?

Most industry experts believe that OFDMA will be the most relevant technology that 802.11ax offers. Downlink MU-MIMO was introduced with Wave-2 802.11ac access points, however, real-world implementation of MU-MIMO for indoor environments is rare:

  • Hardly any MU-MIMO capable clients exist in the current marketplace and the technology is rarely used in the enterprise.
  • MU-MIMO requires spatial diversity, therefore the physical distance between the clients is necessary. Most modern-day enterprise deployments of Wi-Fi involve a high density of users that is not conducive for MU-MIMO conditions.
  • Because MU-MIMO requires spatial diversity, a sizable distance between the clients and the AP is necessary. Most modern-day enterprise deployments of Wi-Fi involve a high density of users that is not conducive for MU-MIMO conditions.
  • MU-MIMO requires transmit beamforming (TXBF) which requires sounding frames. The sounding frames add excessive overhead, especially when the bulk of data frames are small.
  • MU-MIMO would only be a favorable option in very low density, high bandwidth environments.
OFDMA MU-MIMO
Increased efficiency Increased capacity
Reduced latency Higher speeds per user
Best for low bandwidth applications Best for high bandwidth applications
Best with small packets Best with large packets

A very good use case for MU-MIMO is a point-to-multipoint (PtMP) bridge links between buildings. The spatial diversity that is required for MU-MIMO exists in this type of outdoor deployment.

18. Will there be any advantage to use 80 MHz or 160 MHz channels with 802.11ax in the enterprise?

In theory, BSS color could provide the capability to take advantage of 80 MHz channels. However, this is assuming no legacy devices exist. In reality, designing for 20 MHz channels will still be the best practice. If deploying, 40 MHz channels, design best practices will also most likely remain the same:

  • Only use if DFS channels are available
  • Thick walls
  • Low transmit power

19. I thought you said 802.11ax was all about high efficiency and not higher data rates. If 802.11ax introduces 1024-QAM modulation, will there then be higher data rates?

Okay, there is always an exception. First generation 802.11ax radios will support 1024-QAM modulation which will also mean some new Modulation and code schemes (MCS) that define some higher data rates. Much like 256-QAM, we anticipate that very high SNR thresholds (~ 35 dB) will be needed in order for 802.11ax radios to use 1024-QAM modulation. Pristine RF environments with a low noise floor and close proximity between an 802.11ax AP and 802.11ax client will be needed.

20. Will 802.11ax be good for the Internet of Things (IoT)?

802.11ax also includes Target Wake Time (TWT) that will be very useful for IoT devices.  The TWT has first proposed under 802.11h. TWT uses negotiated policies based on expected traffic activity between 802.11ax clients and an 802.11ax AP to specify a scheduled wake time for each client. 802.1ax IoT clients could potentially sleep for hours and conserve battery life.

21. What is BSS Coloring?

BSS Color (also referred to as BSS Coloring) is a method for addressing medium contention overhead due to overlapping basic service set (OBSS). 802.11ax radios can differentiate between BSSs by adding a number (color) to the PHY and MAC headers. Same color bit indicates an intra-BSS. Different color bits indicate inter-BSS.  Inter-BSS detection means that a listening radio treats the medium as busy and must defer. Adaptive CCA implementation could raise the signal detect (SD) threshold for inter-BSS frames while maintaining a lower threshold for intra-BSS traffic. BSS Color potentially decreases the channel contention problem that is a result of existing 4 dB signal detect (SD) thresholds.

22. Are there really three Guard Intervals with 802.11ax?

Yes, 802.11ax defines three-guard intervals of .8us, 1.6us and 3.2us.  The longer guard intervals will enhance delay spread protection. Better resiliency in outdoor environments is expected.

23. Which is better 4×4:4 access points or 8×8:8 access points?

Some of our competitors may manufacture an 8×8:8 access point using a non-Broadcom chipset. It will support eight 5 GHz streams and four 2.4 GHz streams.  Some key points should be understood about 8×8:8 APs versus 4×4:4 802.11ax APs:

  • 8×8:8 APs will initially be more expensive and require more power. The main advantage of 8×8:8 AP is to take advantage of MU-MIMO capabilities which 802.11ax clients will need to support. Regardless of stream count, all APs will support the same number of 11ax OFDMA clients. There is no real advantage with an 8×8:8 AP over a 4×4:4 when using the OFDMA technology.
  • Extreme APs use a Broadcom chipset. The chipset provides for 4×4:4 2.4 GHz radio and a 4×4:4 5 GHz radio. However, one of the radios is an adaptive software-defined radio (SDR),  meaning you can have two dual-5 GHz 4×4:4 802.11ax radios in a single AP. Almost all of the Extreme 802.11ax APs have software-defined radios (SDRs) that allows for dual 5 GHz functionality.
  • Extreme has been a leader in dual 5 GHz technology. Two dual-5 GHz 4×4:4 802.11ax radios transmitting on two separate 5 GHz 20 MHz channels will provide better performance and efficiency. The competitor’s AP 8X8:8 radio will transmit on a single 5 GHz/20 MHz channel and a single 2.4 GHz/20MHz channel.

24. Will there be any 8×8:8 Clients? 

The battery life of an 8×8:8 client will be about 5 minutes. Most Wi-Fi mobile client devices such as smartphones will use dual-frequency 2×2:2 radios because an 8×8:8 radio would drain battery life. In the future, you might will some 4×4:4 client radios in high-end laptops.

25. Some of our competitors are claiming we will need 10 Gbps uplinks from 802.11ax APs.  Is this true? Will we at least need 2.5 MultiGig (802.3bz) Ethernet ports? Let’s look at this historically:

  • 802.11n: Claims were made in 2009 that we were going to need aggregate GbE ports with two cables when 802.11n debuted. Did not happen.
  • 802.11ac: Claims were made in 2013 that we were going to need aggregate GbE ports with two cables when 802.11ac debuted. Did not happen.
  • 802.11ac – Wave 2: When the second generation of 802.11ac chipsets debuted in 2016, several enterprise switch vendors made claims that everyone needed to upgrade their switches to support 2.5 GbE uplinks with 802.3bz MultiGig technology. Did not happen.

Will we need 2.5 GbE or 5 GbE ports for 802.11ax?  The whole point of Wi-Fi 6 (802.11ax) is better spectrum efficiency and a reduction in airtime consumption. Logic dictates that if Wi-Fi becomes more efficient, the user traffic generated by a dual-frequency Wi-Fi 6 AP could potentially exceed 1 Gbps. The fear is that a standard Gigabit Ethernet wired uplink port could be a bottleneck, and therefore 2.5 Gbps uplink ports will be needed. As a precaution, WLAN vendors’ Wi-Fi 6 APs will include at least one 802.3bz Multi-Gig Ethernet port capable of a 2.5 or 5 Gbps wired uplink. Think of this as future-proofing.

Prior to Wi-Fi 6 (802.11ax), the only time a 1 Gbps uplink has not been sufficient is in laboratory test environments or very unique corner cases. Bandwidth bottlenecks almost never occur at the access layer. However, bandwidth bottlenecks can certainly occur on the wired network due to poor wired network design. The number one bandwidth bottleneck is usually the WAN uplink at any remote site.

Although past gloom and doom predictions of access-layer bottlenecks have not come true, as Wi-Fi 6 client populations grow and as WLAN vendors add tri-band radios into their APs, 1 GbE uplinks may no longer be sufficient. Although historically 1 Gbps uplinks have been more than enough, eventually at least 2.5 Gbps uplinks and maybe 5 Gbps uplinks may be needed. Any vendor claims that 10 Gbps uplinks will be needed are fantasy.

26. Will 802.11ax APs work with 802.3af PoE?

Extreme and other WLAN vendors will be adding more radio chains to 802.11ax access points. For example, all three of Extreme’s 802.11ax AP family line will be 4X4:4. The extra radio chain and quad-4 processor will require more power. 802.3at PoE Plus power will be required. PoE Plus requirements for 4×4:4 Wi-Fi 6 APs should be considered a standard requirement. 802.3af power of 15.4 watts will be sufficient to power 2×2:2 Wi-Fi 6 APs as they enter the marketplace.

27. What chipsets are in the Extreme 802.11ax APs?

Extreme 802.11ax APs use the Broadcom chipset.

  • Support for four streams of 802.11ax
  • 4.8 Gbps PHY rate
  • 160 MHz channel bandwidth
  • 1024 QAM modulation
  • Uplink & downlink OFDMA
  • MU-MIMO
  • ZeroWait DFS
  • AirIQ interference identification
  • Full compliance with IEEE and WFA 802.11ax specifications
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Transferring data over your network relies on ‘link performance’, i.e. the cable/component’s ability to transfer a signal while retaining its original information content.  A minimum level of performance is required, and this is measured during testing by the amount of ‘headroom’ that is left. Headroom is affected first by the quality of components used, second, by cable length, third, by cable handling and fourth, by termination quality. The better the quality of materials, the shorter the cable length runs, the better the cable handling during installation and the better the termination all equal a larger link headroom.

UTP Cable Headroom

Each system provides users with headroom assurance that will exceed ANSI/TIA-568-C.2 Category 6 and ISO 11801 Edition 2.1 Class E standards for the following key electrical parameters: Insertion Loss (IL), Near-End Crosstalk (NEXT), Power Sum NEXT, ACR-N, Power Sum ACR-N, ACR-F, Power Sum ACR-F, and Return Loss. You should be aiming for as large as headroom as possible.  the larger the headroom, the more allowance your links have for being able to transmit data quickly and accurately and the more able they are to function when they come into contact with environmental issues, crosstalk or noise.

Conclusion:

If you would like to find out more about, how we will get your data cabling or infrastructure projects right the first time, talk to our team today. With highly skilled engineers located right across the country, you are guaranteed a rapid and effective response. Optimal Technology Ltd can provide you high quality products at low price. Call us on 01973432325, 01973432326, 01973432328, 01973432342 and email to us jay@optimal.com.bd, atiq@optimal.com.bd, info@optimal.com.bd

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The FortiVoice Enterprise IP PBX voice solutions give you total call control and sophisticated communication features for excellent customer service and efficient employee collaboration. Powerful, affordable and simple, FortiVoice Enterprise systems deliver powerful features and value to offices with up to 10,000 phone users. FortiVoice phone systems include everything you need to handle calls professionally, control communication costs and stay connected everywhere
FortiNet IP PBX Voice Solutions

Core PBX Features:

  • SIP/PRI/PSTN trunk
  • T1/E1/R2 signaling
  • SIP/analog extensions
  • Remote extensions
  • External IP extensions
  • Auto attendants
  • Dial-by-name directory
  • Individual voicemail
  • Group voicemail
  • Voicemail to e-mail
  • Ring groups
  • Call conference/bridge
  • Call forward
  • Call hold / transfer / park / pickup
  • Paging to selected phones
  • Intercom
  • Follow-me
  • Rule-based dial plan
  • Scheduled call handling
  • Direct inward dialing
  • Caller-based direct inward dialing
  • Caller ID modification
  • Automatic hotline (direct call)
  • User privileges
  • Personal and system speed dial
  • Personal blacklist
  • Music on hold — audio files
  • Music on hold — live stream
  • Real-time call status monitoring
  • Line/extension appearance
  • Call detail record logging
  • SIP over TLS/SRTP
  • Password policy enforcement

Product Datasheets:

https://www.fortinet.com/content/dam/fortinet/assets/data-sheets/FortiVoiceEnterprise.pdf

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Positions: Pre/Post Sales Engineer (UPS) | Vacancy: 03

Job Context:

EPI-UPS is a British origin company offering an extensive range of data center infrastructure services & it’s UPS, STS and battery manufacture factories in Italy. Optimal Technology Ltd is searching 03(three) Pre/Post Sales Engineers of UPS.

Job Opportunity | UPS Engineers
Job Opportunity | UPS Engineers at Optimal Technology Ltd

Major Qualifications criteria :

1. BSc/ Diploma in Electrical /Electronic Engineering /EEE
2. Experience: B.Sc Engineer = 3 years & Diploma Engineer 5 years
3. Strong communication skill English & Bangla
4. Multitasking capacity
5. Depth knowledge in UPS, Power devices and Electrical System
6. Ability to work on pressure.
7. Hand on Experience on Installation, testing, commissioning and troubleshooting Online UPS.

Employment Status

  • Full-time

Salary:

  • An attractive salary package will be negotiated

Job Location:

  • Dhaka

Compensation & Other Benefits

Optimal Technology Limited presents an exciting opportunity for professional growth in the ICT sector, especially in the Technology Industry. Selected candidates will be offered a smart compensation package according to their experience, academic background, quality & qualification.

  • Lucrative Salary
  • New Laptop
  • Mobile bill
  • Tour allowance
  • Performance Bonus
  • 02 Festival Bonus
  • Yearly Salary Review
  • Annual Picnic
  • Best performance award
  • Professional Training

Deadline:

Thursday, January 31, 2019

How to Apply:

Applicants are required to attach the following documents to their application. To apply please send your CV and required documents to the following email address:  Email :optimaltechnologybd@gmail.com, atiq@optimal.com.bd and jay@optimal.com.bd

  • A copy of your current CV with 2 Photo Copies
  • Names and contact details of three (3) referees
  • Facebook and LinkedIn Profile

Contact Us:

 

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Positions: Network Engineers/Post-Sales Engineers

Job Context:

Optimal Technology Limited is searching Network Engineers are responsible for designing, implementing, monitoring and managing the Enterprise Network Solutions (Routing/Switching/Firewall), Data Center Solutions, Wireless Network Solutions, IP Telephony Solutions, Video Conferencing Solution, IP PA Solutions, IP CCTV Solutions of an organization to ensure maximum uptime for users. Network Engineers will be liaising with our clients to understand their business requirements, and then plan and design complex computer networks which will meet their needs in terms of functionality, security, efficiency, and cost.

Vacancy:

05

Job Responsibilities:

  • Maintaining and administering computer networks and related computing environments including systems software, applications software, hardware, and configurations.
  • Performing disaster recovery operations and data backups when required.
  • Protecting data, software, and hardware by coordinating, planning and implementing network security measures.
  • Troubleshooting, diagnosing and resolving hardware, software, and other network and system problems.
  • Replacing faulty network hardware components when required.
  • Maintaining, configuring, and monitoring virus protection software and email applications.
  • Monitoring network performance to determine if adjustments need to be made.
  • Conferring with network users about solving existing system problems.
  • Designing, configuring and testing networking software, computer hardware, and operating system software.

Experience Requirements:

  • Bachelor degree/Diploma in Information Technology related field of study with a network engineering focus.
  • Minimum 2 to 4+ years’ experience in network architecture and deployment
  • Strong understanding of network infrastructure and network hardware.
  • Ability to think through problems and visualize solutions.
  • Ability to implement, administer, and troubleshoot network infrastructure devices, including wireless access points, firewall, routers, switches, controllers.
  • Knowledge of application transport and network infrastructure protocols.
  • Ability to create accurate network diagrams and documentation for design and planning network communication systems.
  • Provides specific detailed information for hardware and software selection.
  • Ability to quickly learn new or unfamiliar technology and products using documentation and internet resources.
  • Ability to work with all levels of staff within and outside of IT and outside the organization.
  • A self-starter able to work independently but comfortable working in a team environment.
  • Good analytical and problem-solving skills.
  • Dependable and flexible when necessary.
  • Network security experience.
  • LAN and WAN experience.

Employment Status

  • Full-time

Salary:

  • An attractive salary package will be negotiated

Job Location:

  • Dhaka

Compensation & Other Benefits

Optimal Technology Limited presents an exciting opportunity for professional growth in the ICT sector, especially in the Technology Industry. Selected candidates will be offered a smart compensation package according to their experience, academic background, quality & qualification.

  • Lucrative Salary
  • New Laptop
  • Mobile bill
  • Tour allowance
  • Performance Bonus
  • 02 Festival Bonus
  • Yearly Salary Review
  • Annual Picnic
  • Best performance award
  • Professional Training

Deadline:

Thursday, January 31, 2019

How to Apply:

Applicants are required to attach the following documents to their application. To apply please send your CV and required documents to the following email address:  Email : atiq@optimal.com.bd and jay@optimal.com.bd

  • A copy of your current CV with 2 Photo Copies
  • Names and contact details of three (3) referees
  • Facebook and LinkedIn Profile

Contact Us:

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SOLUTION: If you see an error DTLS-3-HANDSHAKE_FAILURE: openssl_dtls.c:2962 Failed to complete DTLS handshake with peer 192.168.202.8” in WLC logs then it’s a Cisco Bug and that’s why AP’s are not joining WLC. To solve this problem first change the time in WLC back to 4-5years eg: If the date in WLC is 1/17/2017, change it manually to 1/17/2012. Then download the latest firmware in WLC and reboot the controller. Once WLC and all the AP’s are upgraded to latest firmware change the time back to 1/17/2017.

Related image

Symptom:

  1. Wireless Access Points fail to connect to the Wireless LAN Controller.
  2. Symptom 1 (where the AP’s certificate has expired):
  3. At the time of the join failure, the WLC’s msglog may show messages similar to the following:
  4. LWAPP-3-PAYLOAD_ERR: Join request does not contain valid certificate in certificate payload – AP 00:11:22:33:44:55
  5. Symptom 2 (where the WLC’s manufacturing installed certificate has expired):
  6. Once the WLC’s MIC expires, the currently joined AP CAPWAP sessions will remain established.

The AP logger will show messages similar to the following:

  •  %PKI-3-CERTIFICATE_INVALID_EXPIRED: Certificate chain validation has failed.
  • The certificate (SN: 7E3446C40000000CBD95) has expired.    Validity period ended on 14:38:08 UTC Oct
  • 26 2021Peer certificate verification failed 001A
  •  DTLS_CLIENT_ERROR: ../capwap/base_capwap/capwap/base_capwap_wtp_dtls.c:496
  • Certificate verified failed!
  •  %DTLS-5-SEND_ALERT: Send FATAL : Bad certificate Alert to 192.168.10.10:5246
  • %DTLS-5-SEND_ALERT: Send FATAL : Close notify Alert to 192.168.10.10:5246

On the WLC side, you will only see a message like this:

  •  #DTLS-3-HANDSHAKE_FAILURE: openssl_dtls.c:2962 Failed to complete DTLS handshake with peer 192.168.202.8

Conditions:

  • This symptom will occur after 10 years of the device manufacturing date.
  • The oldest APs (1120, 1130, 1230, 1310 series) with MICs were manufactured in July 2005, so those APs will be unable to join AireOS controllers starting in July 2015.
  • This problem also affects WLCs approximately 10 years after manufacturing date. For APs using Self-Signed Certificates (SSCs) that were generated by the Upgrade Tool, the symptom will occur on January 1, 2020.

 

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Video conferencing is the technology that allows you to hold meetings with several correspondents who are located in different places while seeing and talking to them in real time. It is different from simple video calling, which is normally one-to-one video communication. Some time ago, video calling or conferencing was a luxury that required expensive and (then) complex equipment and expertise. Today, you literally carry it in your pocket. You can participate in or host video conferencing sessions on your smartphone and mobile device as well as on your computer with basic hardware and adequate Internet connectivity.

Video conferencing has become more common and more accessible thanks to the advent and development of Voice over IP, which harnesses the underlying IP infrastructure of the Internet to make free communication possible. Packets of video, voice, and other types of data are carried on the Internet, thereby making voice and video communication free. You need to be aware that video conferencing has a much higher bandwidth requirement than a simple video call. A typical estimate for a session with decent quality video would be 1 Mbps for each participant. If HD video quality is of importance, consider this as the minimum value. Each participant also needs to have the same connectivity provisions, failing which they risk missing much of the session and also messing around with the whole collective experience.  The most well-established free video conferencing tool around is Skype. As it stands today, however, it may not be the best. Alternative tools include TeamViewer, Google Hangouts, join.me, and many others.

No Need To Travel

Travelling requires time and patience

It costs a lot of money and a lot of time to travel to meet people. With video conferencing, you can organize and hold a meeting within the hour with participants from remote places all over the world. They only need to have the necessary equipment and be present in front of the screen at the chosen time. The pre-meeting organization can be done via email or instant messaging.

Bind Your Mobile Workers

Mobile worker

Your workforce may be scattered around the city of around the country if they are mobile workers. They connect back to base through their mobile devices. You can leverage this existing mobile infrastructure to conduct video conferencing meetings with your workforce. Besides, the visual nature of video conferencing even allows you to check the activities and whereabouts of your employees.

It Aids Telecommuting

Video conferencing is also an essential tool for teleworking or telecommuting- working away from the office, often at home. If your business has a quite open timetable and your workers or co-workers work from home, one way to curb the lack of interaction within the workforce and the lack of downward instruction or upward reporting is video conferencing.

Organize Meetings Independent of Time

Pressed by time

Now that meetings online are free from the huge obstacle of travel expenses and restrictions, they can be organized more often. You can meet people around the world every day or even several times a day. This allows your business to move at the speed the world is moving. Your business moves without you having to move and that’s very fast.

Your meetings can be very short notice. Participants will no longer have excuses related to location and travel; they only have to free themselves. This means that you can schedule video conferencing meetings quickly and get it running quickly. You can also easily squeeze in anyone with a tight schedule.

Humanize Your Conversation

Human interaction through video conferencing

Take this point in contrast with voice communication or email correspondence. A video is moving pictures, which are worth more than a million words. By showing yourself and seeing others, you can work the charms of body language, which is so important in business and other activities involving human interaction. Also, seeing someone while talking to them completely changes the nomenclature of a conversation, be it for business or in a personal relationship.

Show Things

Seeing is believing, and showing is convincing. Through video conferencing, you can write on a board and show it to everyone, demonstrate your latest product, or introduce a new recruit. Often, you can show things that you cannot take along with you in your suitcase while traveling to a meeting.

Learn and Teach Online

Video conferencing in a class

There are great courses being offered and great teachers teaching everywhere, but most of them are probably very far from you. If you are a teacher or trainer, your market may be far from where you are. Video conferencing is a great way of acquiring and sharing knowledge beyond hurdles. While it will not be like being physically present, the interaction is adequate. You will be able to use multimedia facilities like online interactive whiteboards, and you can use online collaboration tools.

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Network has become an indispensable part of our daily life. Many homes and businesses today deploy network with either a wired network connection or a wireless connection. These two network connection methods have their own advantages: wired connection is typically faster than wireless connection and has lower latency. This ethernet cable is not currently recognized by TIA/EIA, but it is designed to support 10G Ethernet with distance up to 100 meters. It can offer transmission frequencies of up to 600 MHz, which is 6 times larger than Cat5e and 2.4 times larger than Cat6.

Advantages And Disadvantages of Cat7 Cabling

Though it’s a newer cable category, it is not the best choice for all network deployment. Why? Keeping reading and you will find the answer in the following part.

Advantages
  • Cat7 Ethernet cable has a higher bandwidth of up to 600 MHz, which is 6 times larger than Cat5e (100 MHz) and 2.4 times larger than Cat6 (250 MHz).
  • Cat 7 has an overall shield as well as individual shielding of every pair. It performs better to protect against outside interference. Therefore, it is suitable for installing in a strong RFI & EMI environment.
  • Cat7 is thicker, more bulky, and more difficult to bend.
  • Cat7 is regarded as the most durable cable and has a longer lifespan of fifteen years than cat5e cable and cat6 cable.
  • Cat7 is compatible with preceding Ethernet cable standards like Cat5e and Cat6. As a result, users can move Cat5e cable or Cat6 cable from existing copper based LAN and install Cat7 without having to change the existing electronics.
Disadvantages
  • Cat7 ethernet cable is not currently recognized by TIA/EIA. It is not a solid, established industry standard.
  • Cat7 is very heavy. Individual pair and overall shielding increase the overall weight and size of this cable, which makes it not a job for cabling. Larger & stronger pathway and more stringent bend radius (100 mm or 4 inch) are required.
  • Cat7 is more expensive. Individual pair and overall shielding also mean higher labor costs and more work towards cable termination.
  • Cat7 cabling may cause ground loop problems. If both ends of the cable are connected to ground, it will lead to ground loops which are a major cause of noise, hum, and interference in audio, video, and computer systems. They can also create an electric shock hazard, since ostensibly “grounded” parts of the equipment, which are often accessible to users, are not at ground potential.

Conclusion

For home network deployment, it is not a great option, because it is more expensive and Cat7 cabling is complicated. However, this type of cable is suitable for the place where needs high speed data transmission and is a high EMI environment. Therefore, in order to get a successful network deployment, you have to make a careful plan, be familiar with the environment, confirm the requirement of network deployment and choose the right transmission media. OPTIMAL TECHNOLOGY LTD offers the best and most versatile copper cables including Cat5e, Cat6 and Cat7 Ethernet cable. For more details, please visit our site.

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Traditional offices and meeting rooms are giving way to open team and mobile spaces, as well as huddle rooms, all of which present challenges for effective collaboration in geographically distributed organizations. Additionally, today’s workers were raised on technology and expect it to be as natural and pleasant as the air they breathe. How quickly and effectively organizations adapt to these expectations and new ways of working is key to sustaining a competitive advantage. Technology trends like mobility, the cloud, big data, social media, and consumerization are removing the many barriers that once prevented effective workforce collaboration within organizations across the globe. Polycom can help you transform the way you and your teams work and compete more effectively with intuitive collaboration tools that fit with the way your teams work, not the other way around.

Buyers Guide - Polycom 2019

PERSONAL: HOME/OFFICE/ROAD

Meet face to face wherever you are. Collaborate at your desk or on the road. Boost productivity by giving your workforce the flexibility to collaborate in high definition audio, video and content with anyone. From any personal devices, from any location.

Personal Video Conference

SMALL/HUDDLE:

Video collaboration is quickly becoming the preferred method of communication. Your workforce needs high-quality audio, video, and content sharing for meetings in small huddle rooms and space.

Small VC

MID-SIZED:

Workforce collaboration needs are changing, and conference rooms need to change with them. Get improved efficiency and productivity with enterprise-grade collaboration solutions that are designed to equip all of your different meeting spaces.

LARGE/BOARDROOM:

Every important business discussion should be face to face. Our executive solutions combine the highest quality voice, video and content sharing to ensure everyone can fully participate in the conversation. Now your teams can collaborate, make decisions and drive impact.

Large VC

IMMERSIVE:

When the meeting is essential, you want the most true-to-life collaboration experience possible. Every detail is perfected to create a visual, audio and content sharing experience that is so real, you forget about the technology and focus only on the objective and content of your meeting.

INNOVATION:

The company that started with a vision of transforming a simple device – the speakerphone – into an indispensable business tool has grown to become a global leader in video, voice, and content collaboration solutions serving industries and enterprises of all shapes and sizes. Polycom is now a part of Plantronics. Polycom helps Organizations unleash the power of human collaboration. More than 400,000 companies and institutions worldwide defy distance with secure video, voice and content solutions from Polycom to increase productivity, speed time to market, provide better customer service, expand education and save lives. Polycom and its global partner ecosystem provide flexible collaboration solutions for any environment that deliver the best user experience, the broadest multi-vendor interoperability and unmatched investment protection. Experience what the workplace of the future could look like in your organization.

INNOVATION

POLYCOM NOICEBLOCK:

Eliminate disruptive noise when you’re not speaking. Polycom NoiseBlock removes distracting noises between comments – from shuffling papers to typing on a laptop – and enables an uninterrupted flow of ideas.

POLYCOM NOICEBLOCK

POLYCOM ACOUSTIC FENCE:

Ensure that your ideas are heard. Polycom Acoustic Fence creates an invisible bubble around your workspace that blocks out nearby conversation and ambient noise, including noisy neighbors and even street noise.

POLYCOM ACOUSTIC FENCE

AUTO FRAME AND ZOOM:

Don’t waste any time adjusting the camera view. Polycom EagleEye Producer automatically frames and zooms in on the participants no matter where they are in the room. Make sure everyone is seen and heard clearly in the video conference.

AUTO FRAME AND ZOOM

SELF SERVICE PRODUCTION:

Polycom VisualBoard technology also enables meeting participants to share annotations on any standard whiteboard of LCD with everyone on the call.

SELF SERVICE PRODUCTION

REAL CONNECT FOR MICROSOFT TEAMS:

RealConnect for Teams is a version of the RealConnect Service designed to support Microsoft Team, allowing standards-based video endpoints to dial directly into Teams meetings. Both Team users and standards-based participants can enjoy a high quality, quas-screen video experience with excellent video and audio.

REAL CONNECT FOR MICROSOFT

REALCONNECT FOR MICROSOFT SKYPE FOR BUSINESS:

The RealConnect solutions simplify communications by leveraging native Microsoft Outlook calendaring and bringing everything and everyone together through the click to join across devices. One in the meeting, the RealConnect solution enhances the Skype for Business client users experience by providing an additional view of meeting participants or panoramic wide-shorts of those sitting in dedicated immersive rooms.

REALCONNECT FOR MICROSOFT SKYPE-1

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Since the copper cable is capable of the advantages, such as less expensive electronics and flexibility, the fiber optic cable can’t just replace it. As a result, while the consumer electronics keep going increasingly wireless, many LANs still rely heavily on copper cables to handle all the heavy lifting when it comes to transmitting data. For example, if you want to plug your computer into a broadband Internet connection, you just need a cable to complete this connection. This paper will introduce some common categories of copper cable used in today’s networks.

Category 3

The CAT3 cable is an UTP (unshielded twisted pair) cable whose data transmission rate is at the speed of 10Mbps. It is one of the oldest copper cable, and was used on a large scale in the early 90’s when it was the industry standard for computer networks. Of course, it is still used today for wiring offices and homes. Although it is still used in two-line phone configurations, it is no longer the the darling of the times when deploy the networks due to the advent of the Category 5 cable.

Image result for CAT3 cable

Category 5

As the successor of the CAT3 cable, CAT5 cable is capable of superior performance. Compared with CAT3 cable, CAT5 cable is the same with it in the structure–UTP, but has higher transfer rate, up to 100Mbps. The fact is that the speed of 100Mbps is also called Fast Ethernet, so the CAT5 cable has become the first Fast Ethernet-capable cable. But Now, it has been replaced by the CAT5e cable.

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Category 5e

The CAT5e standard is an enhanced version of CAT5 cable, which is optimized to reduce crosstalk, or the unwanted transmission of signals between data channels. Similar to CAT 5 in appearance, CAT5e introduces some new wrinkles in the equation. For one thing, CAT5e uses four pairs of copper wire rather than the two that CAT5 relies on. The excellent capacity, that the speed of it can be up to 1000Mbps and the bandwidth can be up to 100 MHz, makes it become the one of the most popularized cable in today’s market. That is also the reason why it can replace the CAT5 cable.

Image result for Cat5E UTP Cable

Category 6

Supporting frequencies of up to 250 MHz and the 10BASE-T, 100BASE-TX, 1000BASE-T, and 10GBASE-T standards, it can handle up to 10 Gbps in terms of throughput. Some CAT6 cables are available in STP (Shielded Twisted Pair) forms or UTP forms. Compared with CAT5e cable, it has better insulation and thinner wires which can provide a higher signal-to-noise ratio, and is better suited for environments in which there may be higher electromagnetic interference. However, when deploying a network, the cost of CAT5e cable is much cheaper than CAT6 cable.

Category 6a

CAT6a’s data transmission rate is up to 10,000 Mbps and the maximum bandwidth is 500 MHz. Since it is in the form of STP, a specialized connector is usually needed to ground the cable. When you’re wiring up your home or office for Ethernet for the long haul, CAT6a is the perfect choice in terms of future-proofing.

Category 7

CAT7 cable, also known as Class F, is a fully shielded cable that supports speeds of up to 10 Gbps (10,000 Mbps) and bandwidths of up to 600 Mhz. It consists of a SSTP (screened, shielded twisted pair) of wires, and the layers of insulation and shielding contained within them are even more extensive than that of CAT6 cables. Because of this shielding, It is thicker, more bulky, and more difficult to bend. Additionally, each of the shielding layers must be grounded, or else performance may be reduced to the point that there will be no improvement over CAT6, even worse than CAT5. For this reason, it’s very important to understand the type of connectors at the ends of a CAT7 cable.

Image result for CAT7 cable SIEMON

Conclusion

When you need a cable to attach your computer to the modem in your home or your office, you can choose the right cable after reading this guide. There are three factors that you should take into consideration: price, the quality of the cables and the kinds of device you have to connect. OPTIMAL TECHNOLOGY can offer the most cost-effective solution for your copper cabling, such as CAT3 cable, CAT5e cable and so on. Besides, the price and the quality of these cables are extremely attractive. Wanna buy? Just visit www.optimal.com.bd

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