Scientel Internship Experience

Lab Room

Internships are a key part in developing a well-rounded resume and in building experience while in college. Internships, additionally, shape and develop your professional character; without my internship at Scientel, I would not be the same person that I am in the workplace today.

The Scientel Internship challenged me in unique ways that are not possible in a classroom setting. I was challenged day in and day out on with issues in networking, security, information technology, and hardware. These challenges required me to work outside of my comfort-zone and research topic’s that I had never worked on before. This allowed me to get a feel for multiple sides of my field. I gained experience and knowledge that was irreplaceable. I was challenged in ways unlike any that are faced in the classroom, I was hands-on with equipment, troubleshooting unique problems.

One of the major things I learned during my internship, through experience, is that explaining the theory of how something works does not equate to having the practical knowledge to perform those tasks. Hands on experience with equipment problem solving is essential in developing your skills and knowledge. Nothing ever works exactly how its supposed to and no problem is ever the same, it is essential to have experience troubleshooting on equipment to a variety of different scenarios.

Lessons Learned

An important lesson is that when you get stuck with a difficult problem to not give up and immediately and find someone to help you solve the situation, sometimes there may not be someone with the answer. I learned that doing your own research and troubleshooting brings you the best long-term benefit. This does not mean you cannot ask for help but if you do not take the time to try and learn it yourself you will miss fundamental skills like problem-solving.

The experience from being able to work hands-on with equipment used in the industry is a huge advantage when entering the workplace. Many graduates have little to no practical experience upon graduation, this makes an internship extremely valuable. An internship experience is what makes an individual stand out from other graduates every year. Another benefit of having the internship was getting to experience multiple sides of the industry. I was able to experience the technical side, business side, and even the skilled labor that is required when moving and installing equipment.

In Conclusion

Being able to experience every part of the process helps make me more knowledgeable in my field and more confident in a variety of situations. I enjoyed being challenged while developing skills and experience during the duration of my Scientel internship and would recommend to anyone that is trying to get ahead in this field to consider seeking an internship.

The Importance of Change Management

CollaborationPicture this……  You run several large Managed Services contracts.  Your Network Operations Center (NOC) is responsible for monitoring and supporting first responder networks all across the country.  Of course, with a first responder network, lives are at stake and these networks cannot be down.  You have been involved from the beginning to ensure that there is redundancy to safeguard against exactly that.  It is now 2:00 a.m. because, of course, it is.  Network alarms seem to only happen overnight.  Your phone is blowing up with text messages, most from network devices and a few from the NOC technicians monitoring these networks.  The alerts and techs are warning of a substantial outage in one of those networks.

All backup devices are up and operating but your focus needs to be the primary devices.  You hop on the phone and start talking to the NOC techs.  They have done all the basic troubleshooting and cannot seem to reach the imperiled devices.  They are asking for approval to escalate internally to the engineering staff, while they contact the on-call customer to get a status and let them know of their issue.  Nobody is answering at the customer location.  You assume it is due to the fact the customer’s primary network is done.  Your engineers are also stumped as they cannot get to any of the devices either.  Even the backdoor interfaces you have installed and configured.

As you are the 3rd level of escalation, it is your responsibility to notify your management counterpart at the customer location.  Just as you are about to make that call, your first level NOC tech calls.  He is in contact with the customer and has just been made aware that they are doing scheduled maintenance.  Starting to feel relieved that there is no catastrophic issue going on there, you think about going back to sleep.  You look up at the clock and realize this whole exercise has taken 2 hours and it is almost time to get up for the day.  You make the coffee and begin to post-mortem.

With proper Change Management Processes

It’s 2:00 p.m. and you are heading into a customer’s Change Management meeting.  You attend this meeting via phone, once a month.  In this meeting, you discuss events that are planned regarding maintenance on the devices within that network.  Your customer announces that network-wide maintenance will occur on the regular 3rd Thursday of the month.  You note it for later reference.  The meeting goes as planned and you begin to prepare a Change Notification for your NOC staff to read and file in preparation for the outage.  The day of the actual work arrives.  Your NOC techs, by design, have switched off the monitoring tool for those specific devices that we know will be affected.  At the allotted time, the primary network is taken out of service.  Your NOC team knows this as they see the secondary devices begin to carry the network traffic.  The customer network team notifies you when they are completed and your team watches as the network nodes all return to green.  Your team then goes in and re-activates all the alarming.  Everything goes as planned and the network is back up and running on its primary devices.

So, what have we learned here?  If you want a good nights sleep and not to be making a pot of coffee at 3 a.m. preparing to tell a customer his primary network is down, create, participate and exchange information prior to any network work.  It is called Effective Change Management and it can make your life a whole lot more bearable.  Not to mention, a better night’s sleep.

What are botnets? How do they work?

Lines of Code

Over the last few years, malicious code, normally known as Malware has been around in some form or the other. Hackers have been breaking into computers over the Internet to leak sensitive information. The world has now been introduced to the concept of Botnets which have caused several security issues.

What exactly are Botnets?

Botnets are a group of computers which are infected with malware to take control of any device connected to the internet. They are like worms. They can be a combination of devices running different operating systems. Devices like cheap webcams, video recorders have little security settings. The hackers find it easy to take over such devices in no time and build huge botnets.

What are Botnets used for?

Botnets are commonly used in DDoS (Distributed Denial of Service) attacks. With the collective computing power from the infected systems, the botnets are highly capable of stealing sensitive information, malware propagation, disruption of the internet, sending spam and spying on individuals or organizations. Cyber criminals or Botmasters as they are called do not build these botnets only to compromise an individual computer. These are designed to infect millions of devices and bring a large network down. There are botnets that can self-propagate, find and infect devices automatically. They are constantly searching for vulnerable internet-connected devices that are lacking the operating system updates or antivirus and security settings.

They are used to commit click fraud. This is nothing but a scheme to fool the advertisers into thinking that people are clicking on their advertisement. Botnets spread due to downloading attachment links. Malicious software can be attached with illegal software or media downloads. When a user clicks on this link of the infected site, the botnet software gets downloaded and gets installed on the user system. Botnets can send spam messages to a million devices in a short period of time. Botnets destroy a large amount of data in the host system. Smart botnets have the capability of going offline for a period and come back again when the targets are not suspecting.

Botnet Attacks

Mirai botnet

The Mirai botnet was responsible for bringing down a large amount of internet traffic and has been said to be the largest of its kind in history. The servers of the company that controls the internets DNS infrastructure were affected by this botnet. It brought down critical sites including Twitter, Netflix, CNN and many others in the US and Europe. The internet outage was caused due to a DDoS attack. Unlike the other botnets that have been built to date by infecting many computer devices, this was largely made up of internet of things (IoT) devices like digital cameras and DVD players. The Mirai botnet mainly targeted these devices with weak or default passwords. Akamai has reported that Mirai is still around with two DDoS attacks of more than 100 Gbps.

 

A new botnet has now been discovered called Reaper which is said to be infecting the IoT devices at a much faster pace than Mirai did. This botnet has the capability to bring the entire internet down. Reaper has been known to affect D-link, Netgear, and Linksys.

Detection

Botnet detection is not an easy task as these have the capability of being dormant for a while and come back when the botmaster programs them to. Botnets try to disguise their origins. In most cases, the owners do not know that their systems have been infected and have become a part of a botnet.

The easiest way a user can find if his computer system has been affected is by using an anti-malware product. Also, the user can look at the processes that are running, the programs that are installed. These might reveal the presence of a botnet infection. But in most of the case, the detection is not so simple.

 

Prevention

As we all know Prevention is better than Cure, the users can prevent their systems from getting infected by following some steps. These can be implemented at an individual user level and at a network level as well.

Individual level:

  • Install anti-virus/ anti-spam software and keep them updated regularly.
  • Turn ON the Firewall settings and restrict unwanted access.
  • Make sure that the OS is updated from time to time.
  • Do not download illegal stuff like pirated music, games, files etc from the internet.
  • Do not click on attachments or links from unknown email messages.


 

Network Level:

  • Have Firewall, IDS/IPS systems, and content filtering in place.
  • Monitoring unusual increase in traffic.
  • Have DDoS protection in place.
  • If individual user systems have been suspected of being botnet infected, try to remove the malware software immediately. If this is not done in time, the other systems in the network might get infected as well.
  • Make sure that all individuals in the company have their systems with the updated software.
  • Monitor firewall logs to identify botnet command and control centers.
  • If any infection has been identified, notify the anti-virus vendors immediately.

 

Take away points

Running anti-malware software on user systems is the basic way to prevent botnet attacks. The most effective way to fight botnets is to be vigilant and be aware of this threat. Keep your systems updated. Help your coworkers to understand the effects of a botnet attack. Make sure you stay away from clicking on unknown email links and attachments. We need to help everyone realize that if one computer gets infected, it might cause harm to the entire network.

With the increase in the IoT and more and technological advancements, the potential of such botnet attacks and their power also increases. Taking preventive action will protect us, our company network, our identity, devices, and data.

 

 

 

 

Basics of Troubleshooting – What you need to know before you ask

Troubleshooting
In any given profession there will always be a time where something goes wrong, some tool malfunction, or something that you’ve used every day seems to act differently. In today’s world, most of the time the problem is computer related. We’ve come to depend on these devices and their functionalities, whether it’s a laptop, cellphone, or server service.  It often causes frustration and loss of productivity when they fail.

What to do when everything goes wrong?

When this happens what’s the first thing you do? Call IT? Call a friend? Throw it away? This is the first step to really learning and understanding the tools we use every day. What do we do when it goes wrong? In most cases the best thing to do is the good ol’ standby…reboot. If it’s electronic and has an operating system running on it there’s a good chance that forcing a reboot will help the issue. If not, then you need to look further.

Determine the issue

Since the reboot did not work, think about the issue being experienced. Is it application related – does another program/app work? Is it network related – does the device itself work but you can’t access the web or any of your services? Is it hardware related – does the device seem “stuck”? Is it working but you can’t launch any applications? Drilling down into the issue and determining what’s happening rather than just that something happened is key. Once you have narrowed down the issue to one of the general buckets (application/network/hardware/operating system) it will allow you to move onto the next phase of the troubleshooting process.

Troubleshooting

The next step would be to try to use a search engine to try to troubleshoot, if available. There is a wealth of knowledge on the web and most likely the issue you are facing will have been documented already. The trick to troubleshooting on the web is to describe the issue accurately. For example, if you have an error message on your computer with an error number. Don’t just search for the error number, rather search for the entire message that’s displayed as well as the name of the application you were trying to use and the operating system running. It seems like a lot to type into a search bar but the more you have describing the issue, the more likely you are to find exactly what you are looking for in the first page of results.

After all of this you may still have the issue and need to call into IT or someone else knowledgeable on the equipment. It is very important that you articulate to that individual what is happening just as you described in the search online. The more information you have up front, the better your chances are to get resolution from the technical representative you are working with. Make sure to describe what you were doing when the problem occurred, or what you were attempting to do, and what happened. However, please try not to get too upset when they ask you to reboot.

Wi-Fi Standards: Past, Present and Future – What They Mean to You

Back of Wi-Fi Router“Wi-Fi” is now such a commonly used term, people don’t give it much thought, other than knowing they can get their Internet through wireless. Across America in homes,  airports and coffee shops, people are looking to connect their laptops, tablets, phones and other devices to the nearest wi-fi network.  But what is “Wi-Fi”, and where is it going in the future?

Wi-Fi has its origins in a 1985 ruling by the FCC, that released the ISM Band (2.4 & 5 GHz)  for unlicensed use.  Beginning in 1997, the IEEE (Institute of Electrical and Electronics Engineers) developed a wireless standard known as 802.11 by which data can be communicated over a wireless link.  Since that time, there have been a number of amendments to this standard, each with increasing speeds and improved coverage capabilities.

The earliest standards were 802.11a and 802.11b, running at frequencies of 5 GHz and 2.4 GHz respectively.  By year 2000, the 802.11b was most common, with peak throughput bandwidth of 11 Mbps. In 2003, the 802.11g standard was developed that increased bandwidth speeds to a peak 54 Mbps.

Forward on to 2009 was the advent of 802.11n, a dual-band standard that runs at both 2.4 and 5 GHz.  This time the peak bandwidth speeds increased to 600 Mbps. Jump to 2014, then 802.11ac hit the market with potential speeds up to 3 Gbps. The introduction of the “ac” standard was the first time the “MIMO” antenna technology was used – Multiple In, Multiple Out.  This multiplies capacity of the radios by transmitting different signals over multiple antennas. An addition to the “ac” standard is called   “Wave 2”, which introduces a modulation method known as OFDM (Orthogonal Frequency Division Multiplexing).  OFDM converts 1 high-speed data channel into multiple parallel lower-speed channels.  This results in better coverage and longer-distance reception. As this article is written in the beginning of 2018, this is the wi-fi standard of today.

What does the future hold?

Behold the newest commercial  wi-fi standard, 802.11ax. What is so special about “ax”?

The new 802.11ax dual-band standard is designed to improve spectral efficiency, especially in dense deployment areas. The most notable thing about “ax” is the dramatic jump in speed, at up to 4X the rate of “ac”, for a peak bandwidth of 10.5 Gbps. So ax has two major things going for it – better coverage in dense wi-fi areas, and much higher speeds.  The “ax” wi-fi gear will be publicly available on the market in early 2019.

 

Other Interesting Future Wi-Fi Standards

What about all this talk of Internet of Things (IoT)? How do you connect refrigerators, thermostats, dishwashers, and a host of other devices to the network?  Say hello to 802.11ah.  This is known as Wi-Fi HaLow.  It runs in the 900 MHz frequency for easy penetration through walls. It has lower power consumption and wider range than standard wi-fi, designed to connect to IoT devices. It is also used for Smart Meters, M2M (machine-to-machine) and rural communications.

Want to have the latest Home Theater setup?  Give 802.11ad a try. This standard is extremely high frequency millimeter-wave, running at 60 GHz.  With bandwidth throughput of 7 Gbps, it is designed to provide wireless audio and video streaming for home theatre systems, office devices, displays, and other uses.  It only goes short distances and will not penetrate through walls.  But 802.11ad is positioned to play a big role in home theatre systems in the future.

Of course there are other wireless standards on the roadmap for the future, including 802.11az running at 60 GHz to be introduced in 2021.

With every passing year the speeds keep getting faster and the coverage capabilities better.  Do you have an idea of what you want in your future wi-fi? Submit your ideas to the IEEE, as they are interested in hearing them.

Journey of a Network Engineer

Network DriveA lot of technology newbies want to be Network Engineers right out of the gate these days but there are valuable lessons that you can learn from starting out at the Desktop Support role and working your way up. The rewards of being a Network Engineer is great but if you don’t understand how a computer functions and talks to a Server, Domain Controller, DNS Server, etc. then how are you supposed to troubleshoot a potential network issue? I’d like to share some insight and take you through some life experiences I learned along the way to becoming a Network Engineer today.

Building Blocks for Success

To begin with, how many people who are Network Engineers have built a desktop from the ground up? I don’t mean popping a disk in and going through the pre-directed menus to set your preferences on time-zone, computer name, etc. I mean truly crack the case open and understanding the components that make up a computer. The RAM, hard drive, power supply, types of PCI expansion slots, and Video Card. Most Engineers that I meet and talk with start studying Cisco Day 1 and try to get certified to get a job. While there is nothing wrong with this there are valuable steps that are missed by not understanding how a desktop works, how a server works, how storage stores files, and how the network can affect all of this communication.

At the end of the day Network Engineers must be able to build and maintain the highway that all the components talk with. I like to use the analogy of a highway; I am going to build a highway, but to build that highway I must understand what is going to be moving over that highway. What if there are problems with certain cars that go down that highway? How do I fix their problems? Without knowing something about how that car drives on the highway and where it’s trying to go I am unable to fix any problems.

My Career

Let me take you back early in my career. Coming from a generation that started out with Windows 3.1 and having to understand that drivers for components really meant something as to how the computer functions you must really understand what you are doing or there is no boot process taking place. I used to think to myself this is horrible and why couldn’t the process of building a PC be any easier. What I didn’t realize at the time was that all the processes I was going through was a life learning experience in troubleshooting. It took patience (lots of patience) because with different processor chipsets you had different challenges. Hard Drives for example use to have pin connectors (Exhibit A) that were bridged together to specify if a hard drive was the primary, secondary, or stand alone.
(Exhibit A)

Then there was the process of building the machine with an operating system once it would boot properly. I remember the days that all you needed to install the operating system was to have DOS installed….yes DOS. Once DOS was installed then you had a set of Diskettes to load the operating system. Once everything moved to Windows 95 (A, B, or C) and before CD Drives existed the entire operating system (OS) was loaded with 25 Diskette drives….one after one asking for the next one to be inserted! You could only hope that one of the diskettes was not corrupt along the way!

Life Lessons Learned

So why am I telling you all of this? Well I want to share this because I think the time spent forcibly learning and installing all these components has stuck with me through the years. The tasks you think are the worst or the most cumbersome at times are the ones that later in life you look back at and realize are what has helped you the most in your career.

As younger generations enter the work force the pace is moving faster with everything expected to arrive instantaneously. The challenge for Network Engineers today is to solve the problem in minutes… not days or weeks. The progression of learning from the ground up builds a foundation of understanding how everything works in a connected World. No matter what desktop your talking about, server platform, Internet connection, storage platform, all the base connectivity with how each layer interacts between one another is still the same with some minor differences here and there.

What it means to be a Network Engineer

To be an efficient Engineer, a sound understanding of the interaction between the server platform, Internet connection, storage platform, and all the base connectivity are fundamental. An efficient Network Engineer can answer these essential questions:

1. What happens when one desktop can get to a network share, but others cannot?
2. What happens when all users can get to one website, and others cannot?
3. How do you approach figuring out the solution to the problem?

Having the comprehensive knowledge and ability to troubleshoot is what sets apart a Network Engineer. The time spent learning and developing skills to understand and troubleshoot the little things is what makes a World Class Engineer. In addition to being a World Class Network Engineer, it will make your job a LOT easier in the long run. Now I’m not saying that everything is going to be easy to figure out but as you figure out how to troubleshoot issues you will start to remember things you encountered along the way and everything will start to add up.

Disclaimer

I don’t want everyone to think that they MUST work in Desktop Support and then work their way up, but I just wanted to say that in my career I started out in Desktop Support, worked my way into understanding Servers, then built Servers (File Servers, Fax Servers, Domain Controllers, Print Servers, etc), after which I started my certifications into Microsoft (MCSE NT 4.0). From Microsoft I started learning about storage; specifically high end storage with Fiber Channel (McData Switches). I also mastered how mass storage drives worked on the network with Clarion, LSI Logic, and others.

After all this experience, I then decided I needed to progress to the network side to see what makes all this work; that is when I decided to start my career into Cisco. Understanding how all these components work with one another made learning networking very simple as a natural progression for my career. What was even easier was the ability to troubleshoot issues when they popped up which I attribute all my previous hands on experience with various systems that run and function on a network!

Final Takeaway

What is your takeaway from all of this? It’s not how fast you can get your Cisco Certification or industry Networking Certification and getting a job working in networking as a Network Engineer that will make you valuable. It’s the understanding, communication with the customer, and troubleshooting experience you bring to the table plus being able to get a network, email, Internet, or users back online with little hesitation. As a Network Engineer there shouldn’t be a DMARC for where you stop troubleshooting. Step out of your comfort level and troubleshoot whatever comes your way if the opportunity presents itself. You’ll be glad you did later down the road. Whatever you do don’t stop learning!

How to Setup a PTP450i Link

Any PTP link consists of two radios, one is configured as a Master radio and other configured as a Slave radio. There are 3 basic configurations you’ll need for each radio:

  1. General- to select the radio as Master or Slave
  2. IP- to configure IP address for the radio
  3. Radio- to configure frequency, channel size, transmit power etc.

Radios can be accessed by their default IP address 169.254.1.1 and each radio is shipped as PTP slave from the factory.  To make changes to the above mentioned areas of the radio, access radio GUI using the default IP address and configure it. This post will describe how to setup a Cambium 5GHz PTP450i Link.

Configuration for the Master Radio:

Access the radio GUI using the default IP address 169.254.1.1, by default there is no username or password. Once you are in radio GUI, select configuration menu from left hand side, click on the General Tab and configure the following parameters as shown in Picture 1:

  • Device Type -Master
  • Sync Setting- Select the source of timing pulse
  • Region- Select the correct region and country for your deployment
  • Save Changes and reboot

Picture 1

Once the device reboots go to the IP tab and configure an IP address, Subnet Mask and Gateway IP addresses and hit save changes and reboot.  Now we will move to the most important tab in the configuration “Radio”. In this tab you configure the following parameters as shown in Picture 2.

  • Select a frequency band you want to use for the link
  • Select a frequency carrier/channel, based on your selection of band the channel frequencies will vary
  • Select a channel size- this will vary with frequency band
  • Assign a color code for the Master unit
  • Select an appropriate frame confi  guration for your network/link requirements (Downlink Data %)
  • Select a transmit power for the radio- this will vary based on the frequency band
  • Save changes and Reboot

Picture 2

At this the point master radio is ready to connect to the slave radio.

Configuration for Slave radio:

Access the radio via its default IP address 169.254.1.1. Since the radios are shipped in Slave configuration, you don’t need to change anything under the general tab in configuration menu other than making sure that the Slave radio is configured to the correct region and country code. After that, move to the IP tab and make sure to configure the correct IP Address, Subnet Mask and Gateway Address and save changes and reboot.  Once the Slave unit reboots configure the radio tab. All the settings in radio tab for Slave, should mimic those in the Master radio as shown in picture 3.

  • Select the channels for the band of operation selected in Master radio
  • Select the “Channel Bandwidth Scan” to match the channel bandwidth of Master Radio
  • Select the color code same as in Master Radio
  • Select Transmit Power required based on link budget calculations.
  • Save changes and reboot the Slave Radio

Picture 3

At this point Slave radio is ready to connect to a Master radio.

 

That concludes the setup for a PTP450i link.

How Duplication Will Increase Efficiency and Enhance Innovation

A process is only as good as its ability to duplicate. This is especially true when it comes to the lifecycle of business. For example, if I was in the business of making sandwiches, I would want a process set up that would allow the max number of sandwiches to be made. I would want to run tests and analyze what would be the most efficient way to make the best sandwich possible, then duplicate the same way of making that sandwich to ensure peak performance.

This would mean I would have a predetermined amount of ingredients that would stay consistent for every sandwich. If I reinvented the wheel every time I made or sold a sandwich, my business would fail because I couldn’t make enough or have a consistent product for my customers.

In the world of Project Management, duplication should be the peanut butter and jelly of your business, or the ham and cheese if you prefer. Reinventing the wheel every time a new customer or project comes on board will not only create more work for the PM but also doom the project to fail. This may not be an immediate or painless demise either. It would be a slow and painful disease that spreads throughout the organization. Don’t start to panic yet, this disease is completely preventable! Creating an environment of duplicatable processes is the vaccination.

Your next thought may be, well how do I obtain such a vaccine? Well, this is where it gets a little tricky. You must create your own. I will first say that I’m no expert in the field of change or duplication and I don’t have a magic mix of ingredients. However, I can tell you how I have successfully created an environment of duplication.

The Solution

My first step was to create an environment of innovation and collaboration within the members of my team. Change is more likely to take affect and be carried out if all members of that change have some skin in the game. I spent several weeks speaking with each member of my team one on one as well as creating group sessions. We would discuss things like: What is going well with the current process? What isn’t going well? Why do you think those things aren’t going well? What do you think we could do differently to make things work better?

Change is more likely to take affect and be carried out if all members of that change have some skin in the game.

After taking all that information, I used it to assign tasks to every member of the team. Writing new policy documents, fixing old ones, anything to keep them as involved in the process as possible. Once we were able to get all the ground work laid, I made it their responsibility to ‘keep making more sandwiches’ in a matter of speaking. When someone new comes in, I ask one of the other members to train them. We would then evaluate the process while training new hires and perpetually improve the process through fresh input. The processes are flexible and allow for continuous innovation, which is carried out by the positive attributes of the team along with its new members. Our key to having the best business practices is that we remain open to improving and innovating. Once the team works, the dream works! Just continue to train to repeat the same process that was already established to work, some situations might require minor adjustments but for the most part things should be streamlined.

 

The Results

Let me just end with a small disclaimer, creating an environment of duplication DOES NOT mean to remove growth or innovation. It is possible to duplicate a process while still innovating new ideas. An environment of duplicating processes should make the day to day activities more streamlined to open the opportunity for growth and innovation, not hinder it. Creating a process of duplication has allowed our support team to save over 40 man-hours every time we start supporting a new customer and helped us to expand our project base by approximately 20% in the past year. On that note, I encourage you to look at your processes or ‘the sandwich’ on your plate. Is it a well-executed sandwich that you could pass to your teammate and have them make the same one? If not, maybe it is time to start creating an environment of duplication within your organization.