Software Defined Networking - Network Virtualization

a. History of SDN
This lesson: Network Virtualization
 - What is network virtualization?
 - What is its history? (w/examples)
— - 1990s (and before): Switchlets
— - Mid-2000s: VINI, Cabo
— - Looking forward
ž - Network virtualization and SDN
Evolution of Supporting Technologies
 - Central network control: Dates back (at least) to AT&T’s network control point (1980s)
ž - Programmability in networks: Active networks (1990s)
ž - Network virtualization: Switchlets (1990s), VINI (2000s)
What is Network Virtualization?
 - Representation of one or more logical network topologies on the same infrastructure.
ž - Many different instantiations
— - Virtual LANs (VLANs)
— - Various technologies and network testbeds
— - Today: VMWare, Nicira, etc.
Benefits of Network Virtualization
 - Sharing: Multiple logical routers on a single platform
ž - Sharing: Resource isolation in CPU, memory, bandwidth, forwarding tables, …
 - Customizability: Customizable routing and forwarding software
 - Customizability: General-­‐purpose CPUs for the control plane
 - Customizability: Network processors and FPGAs for data plane

b. Three Examples of Virtual Networks
Tempest: Switchlets (1998)
— - Separation of control framework from switches
— - Virtualization of the switch
ž - VINI: A Virtual Network Infrastructure (2006)
— - Virtualization of the network infrastructure
ž - Cabo: Separates infrastructure, services (2007)
The Tempest Architecture: Switchlets
 - Multiple control architectures over ATM
ž - Separation of switch controller and fabric via open signaling
ž - Partitioning of switch resources across controllers

c. Switch Divider
 - Partitions port space, bandwidth, buffers
ž - Different controllers control each switchlet

d. VINI: Virtual Network Infrastructure
 - Runs real routing software
ž - Exposes realistic network conditions
ž - Gives control over network events
ž - Carries traffic on behalf of real users
ž - Shared among many experiments

e. XORP: Control Plane
 - BGP, OSPF, RIP, PIMSM, IGMP/MLD
ž - Goal: run real routing protocols on virtual network topologies
Click: Data Plane
 - Performance
— - Avoid UML overhead
— - Move to kernel, FPGA
ž - Interfaces ð tunnels
— - Click UDP tunnels correspond to UML network interfaces
ž - Filters
— - “Fail a link” by blocking packets at tunnel

f. Concurrent Architectures are Better than One
 - Infrastructure providers: Maintain routers, links, data centers, and other physical infrastructure
ž - Service providers: Offer end-to-end services (e.g., layer 3 VPNs, SLAs, etc.) to users
 - Today: ISPs try to play both roles, and cannot offer end-to-end services

g. Examples in Communications Networks
ž - Two commercial examples in IP networks
— - Packet Fabric: share routers at exchange points
— - FON: resells users’wireless Internet connectivity
 - FON economic refactoring
 - Infrastructure providers: Buy upstream connectivity
 - Service provider: FON as the broker

h. Evolution of Supporting Technologies
 - Central network control: Dates back (at least) to AT&T’s network control point (1980s)
ž - Programmability in networks: Active networks (1990s)
ž - Network virtualization: Switchlets (1990s), VINI (2000s)
Goal: Control and Realism
 - Control: Reproduce results
— - Control: Methodically change or relax constraints
ž - Realism: Long-running services
 - Realism: Connectivity to real Internet
— - Realism: Forward high traffic volumes (Gb/s)
— - Realism: Handle unexpected events

i. Similar Trends in Other Industries
Example: Commercial aviation
 - Infrastructure providers: Airports
— - Infrastructure: Gates, “hands and eyes” support
— - Service providers: Airlines
Enabling End-to-End Services
 - Secure routing protocols
 - Multi-provider Virtual Private Networks
 - Paths with end-to-end performance guarantees

Software Defined Networks - Active Networks

a. History of SDN
This lesson: Active Networks
ž - What are active networks?
— - Motivation for active networks
— - Technologies behind active networks
 - How do active networks relate to SDN?
ž - The legacy of active networks

b. Evolution of Supporting Technologies
Central network control: Dates back (at least) to AT&T’s network control point (1980s)
 - Programmability in networks: Active networks (1990s)
ž - Network virtualization: Switchlets, XEN, VINI (1990s)

c. What are Active Networks?
Networks where switches perform custom computations on packets
ž - Examples (and motivation)
— - Trace program running at each router
— - Middleboxes: firewalls, proxies, application services

d. Origins of Active Networks
DARPA research community (1994-1995)
ž - Identified problems with today’s networks
— - Difficulty of integrating new technology
— - Poor performance due to redundant operations at several protocol layers
— - Difficulty accommodating new services

e. Motivation for Active Networks
Accelerating innovation
— - Internet innovation relies on consensus
— - Takes ten years from prototype to deployment (standardization, procurement, deployment)
ž - Active nodes allow routers to download new services into the infrastructure
— - User-driven innovation

f. Idea: Messages Carry Procedures & Data
Active routers coexist with legacy routers
ž - Each programmable switch can perform additional processing
User “Pulls” and Technology “Push”
User Pull (demand)
— - Proliferation of firewalls, proxies, transcoders, etc.
 - Goal: Replace ad hoc approaches
ž - Technology Push (enablers)
— - Safe execution of mobile code,Java applets
— - OS support
 - Scout: real-time communications
 - Exokernel: safe access to low-level resources
 - SPIN: trustworthy code generation

g. Two Different Approaches
Capsules (“integrated”)
— - Every message is a program. Active nodes evaluate content carried in packets.
— - Code dispatched to execution environment
ž - Programmable Switches (“discrete”)
— - Custom processing functions run on the routers
— - Packets are routed through programmable nodes
— - Program depends on the packet header

h. Capsules
Type
— - Forwarding routine to be executed (carries code by reference)
ž - Previous address
— - Where to get the forwarding routine from if it is not available in the present node
ž - Dependent Fields
— - Parameters for the forwarding code
ž - Payload
— - Header + data of higher layers

i. Some Previous Notable Projects
ANTS (MIT): Packet capsules (Java programs)
— - Some limitations for QoS guarantees. Arizona implemented Joust JVM to provide better real-time performance.
ž - SwitchWare (Penn): Programmable switch, scripting language to support invocation of switchlets
ž - Smart Packets (BBN): Network management
ž - Open Signaling (Columbia): NetScript, a language to provide programmable processing of packet streams.
ž - Tempest (Cambridge): Switchlets (more next time)
Timing was off
— - No clear application (pre-data center/cloud)
— - Hardware support wasn’t cheap -- everyone was using ASICs, whereas now TCAMs, FPGAs, NPUs.
ž - Some missteps
— - Security, special languages for safe code, packets carrying code
— - End user as programmer (vs. network operator)
— - Interoperability
ž - In contrast: OpenFlow did a good job grappling with backwards compatible with switch hardware.
— - Simple firmware upgrade.
— - Switch hardware already supported the basics.

j. The Legacy of Active Networks for SDN
Programmable functions in network to enable innovation
ž - Demultiplexing programs on packet headers
— - Planetlab, Flowvisor, GENI, etc. all use this
ž - Paying attention to middleboxes and how these functions are composed

Principles of Computing - Introduction part II

First and foremost, we want you to be able to solve complex problems using a computer in a principled way. We don't want you to just sit down at a computer and start coding and hope for the best.

Instead, we want you to think about what you're doing and why, right? Part of this is mathematics. So we're going to introduce you to some of the mathematics that computer scientists use to solve problems every day. And this will help you approach a wide variety of different problems.

We also want you to build upon the programming experience that you have. We want you to be able to think about what you're doing and why, and to be able to build more complex programs, okay?

And part of this is teaching you some of the principles of good programming. It's one thing to be a programmer. It's quite another to be a good programmer.
So I want you to start thinking about how you're approaching a problem. Why you're approaching it in a certain way. And whether or not there are better ways to approach that problem, okay? And this will help to make you a better programmer.
So we want to talk more about computer science in the abstract, rather than programming in the specific. However, programming is an integral part of computer science, so you do need to know how to program.

Introduction to Thermodynamics - Drivers for Changing the Way We Use Energy

The first would be the computer you're watching this on, or your cell phone, or if maybe you have it connected to a TV. Lots of different energy systems that are flo, that are obvious to us as we look around the room.
The fact that your cords were connected to, the outlets, and that those outlets were connected to power plants and those power plants were generating power through maybe nuclear, or coal, or gas, natural gas. So there are thousands of examples of energy transfer system around us. Even the smallest from the microchips that are in our computers and they dissipate heat and that has become a rate limiting problem for the, for the chips that are in our computers.

To the energy densities associated with the batteries that are in our cell phones. We want to have a lot of energy but we don't want to pay a lot in terms of the volume or in terms of the mass.
So, many examples that we can see all over. So, what are the drivers for changing the way that we use energy currently? In terms of power generation for many different sectors. So, let's kind of review. Let's start with a review of where are we now? Well, global demands for energy are extraordinarily high.
What you're seeing in this figure are, is a composite of some photographs that were taken by NASA. This is, from their science source, and it's entitled. Lighting up the ecosphere. But these are nighttime shots, again, pieced together around the world, and you can see the lights from North America are quite bright. You know, the high population density centers around the world you can see are quite, quite bright. But you can also see areas that are quite daw, quite dark as well.

So we can see there's a lot of energy demand, and there's a lot of energy demand around the world. Now what I'm showing you is a population cartogram and this was actually generated by the University of Michigan professor, physics professor Mark Newman.
And at the time Mark was interested in trying to generate graphical ways of interpreting data. He didn't mean to be controversial but he produced a couple of figures. That show you the population. Where what he's done is distorted the size of the countries based on their population. So, you can see, you know, the United States is quite large. China and India, where the bulk of the global population are currently, are very, very large. And you can see that, you know, several countries are quite small. You can see Russia has shrunk considerably. We can see a distortion here in, in Europe and, and, look at the distortion in Australia to represent the low population in those countries. In the next cartogram, here we can see energy consumption. So now, we look at the places around the world, and we can see a dramatic shift. So the United States is now even more bloated, further than even beyond the population. But we can see that China and India have shrunk, Russia has expanded. Australia has expanded some. But Africa has virtually disappeared, and Brazil has gone on a significant diet.

So the point is, is that, the, there's countries that use a lot of energy. But they aren't necessarily countries where the bulk of the population is. So we have two drivers that we can see already, developed versus developing nations. So industrialized nations versus less industrialized nations. And, sheer population.
Those are both drivers for global energy consumption. And this graph shows you the same sort of discussion or same topical points. Now, of course in a conventional bar graph form. Here, the axis, this is a plot of total population by region. A four snapshots in time. 1950, 95, 25, and 2050. 1950 and 1995, the data from these two years are actual data. The 2025 and 2050 data are projections of where people feel the estimates are, the estimates are for population growth by region. And specifically the regions we're looking at are Oceania, North America, Latin America and the Caribbean, Africa, Europe and Asia. And there's lots of conclusions we can draw, just based on just looking at this figure.

First of all, we can look at what is the current population, the 1995 data, sort of. Sort of, current. Not quite up to the year 2013. And we can see that the bulk of the population currently exists in Asia and we can also see where is the projected growth going to occur. And we can see that the projections show that the population growth between now and 2050 is almost exclusively in developing nations. In what's often referred to as the Bric nations. Bric being Brazil, Russia, India, and China. And we can see again, while we already have a significant population in Asia, that population is, is projected to grow by almost 2 billion people.
It's projected that Europe will actually lose population, actually see a decline in population. Africa will see an increase. Latin America and Caribbean will see an increase too. North America is projected to almost flatline. So the point of this is that energy, as we expect, is driven by developed versus non less developed nations. Industrialization does of course drive energy demands. But so does population growth. And population growth in Asia is expected to increase dramatically. So, we expect global energy demands to dramatically increase in Asia.

Here we have the gross national product per capita in US dollars as a function of energy use per capita in millions of Btu. And we'll talk about energy units here, but this is the British Thermal Unit, let's say unit of energy here. So this is increasing energy, this is increasing GNP, both on a per capita basis. GNP is generally an indicator of the quality of life. Sort of, and it's also a general indicator of developed nation. And we can see here, we have Japan, has a very high GNP. Germany, France, United Kingdom, US, we can see are all above average, okay? Now I should say that these data are taken from World Bank data.
This is, this is as of 1995, so I took these data that are available to the public, and plotted these. And you have to decide, you know, which countries you want to include when you calculate these averages. So, I think I chose approximately the top 30 countries, something like that. In terms of the top GNP producers and top energy users so you would get a different average if you included more countries. And that average would actually go, decrease both in terms of GNP and in terms of energy per capita. The point being is that these developed nations are high GNP and high energy users, both on a per capita basis.

India and China, circa 1995, so a little bit dated. Were very low GNP, and very low energy use on a per capita basis. So we've already discussed how we expect to see significant population growth in these countries. We would also expect to see significant increase in quality of life and industrialization.
Both of which are going to move these countries in the North East direction. So they're going to move from this quadrant to this quadrant. Those are going to be compounding effects. An increasing population that used more energy per capita.

Enhance Your Career and Employability Skills - Uncovering your implicit values

And why it's important to be aware of your values, when it comes to making decisions in your career. We're going to look at a couple of, activities, that will help you to be more aware of your values. So we have to identify them, and to articulate them. And those two activities, are looking back and looking forwards. Because one of the difficulties when it comes to making career decisions, is, you tend to be focused on the things that are important to you at that moment in time.
But when you're making long term career decisions that have a long term impact on your future, you need to make sure that you're taking into account all the things that could be important to you.

So we're going to look at two activities. One activity is looking at past. It's called a lifeline exercise. One activity is, is looking at the future. And it's based around a, an approach to thinking about your career called test and learn. So first of all, looking at the past. One of things we're going to get you to do. Is an activity called lifeline. And what it does is it gets you to plot. Your life.
So you get a horizontal axis, which is time. And you can do it in chunks. It's up to you how you do it and how far back you go. But you might want to go back in a couple of years, four years, six years, eight years, ten years. It's entirely up to you. And on the vertical axis is your emotional experience. So above the line are positive emotions. Curiosity, times when you felt really intrigued by the world and interested in what was going on. Hope, times when you felt that there was things to look forward to and that you were enthusiastic about. Gratitude, times when you felt grateful and happy with what was being given to you. Joy and enthusiasm and excitement. Or it could be things like pride and, and sense, sense of achievement or even generosity, in terms of you were feeling like you were giving to the world.

So again, everywhere thinking about how you plot those. Obviously, on the, below the line on the vertical axis are some more negative emotions like worry, anger, dread, fear, apprehension, anxiety. Is that frustration or even envy and maybe selfishness on those occasions, when did you feel those things? And so we need to do is plot a line, in relation to time about when you experienced that emotion, so at certain times you might have experienced quite a lot of hope as you were looking forward to the future.
And then you got into a new job, and, actually, that led to frustration because it wasn't quite what you thought it was. But actually, after a while, through you're own kind of personal effort you turned the situation around. And so you felt a sense pride growing in that you were able to, to change what was going on around you. And that led to a sense of enthusiasm for, for pushing forward, and a sense of accomplishment in terms of doing that.

But then maybe something else happened and you know, you saw somebody else who was doing better than you and you felt a sense of envy. And you felt, hang on a minute, I maybe, I thought was doing good but I'm not doing as well as I thought. But then that turned around and maybe you got an idea that well, okay, if they can do it, so can I and so you got a sense of hope from that and you started to work on that. And so on.
And so most of our lives are a series of ups and downs that we go through as, as our needs are met or unmet, as or values are satisfied or not satisfied.
And so that's one of the clues, what our emotional state is a clue to the values that we have. And by listening to and being aware of those emotional states and how they change. We can get an idea of what are the things that are important to us. And that's one of the key elements of self awareness. Be able to identify those emotional states and then reflect and we'll work out what they mean. So that's one of the first steps.

Okay, so assuming that you've plotted this emotional rollercoaster. The next thing to do is to look for patterns. To, so for each of the peaks and troughs in your lifeline, to remind yourself what was going on at the time. What was happening to you, and what were you doing? And to think about, what that might mean in terms of what was important to you at the time.
Which will prompt you to think about what was important. But the key thing here is to look for patterns, are there things that repeat themselves regularly throughout your life. Themes that seem to be important continually. Are there some things that seem to be important at some point and not at others? And also other things that are important both in the positive and negative emotions. Because positive emotions maybe our clue as to when that need is being satisfied and negative emotions when it's not being satisfied.

And so to look for those patterns inconsistencies but also the changes as well over time. And that's another set of questions to ask yourself, is, how have things changed, have somethings grown in importance, have other things diminished in importance over time as, as I've experienced things. So that's one exercise to try and what we'd like to do is have a go at that and reflect on those experiences and to think about things that happened to you.
And maybe share some of the things you've learnt about your experience in terms of what is important to you. And then as you see other people's experiences what we'd like you to do is we'd like to encourage you to turn those into questions. But you can start doing that now. And so for example if you identify that one of the things that has been important to you over your life you've always experienced positive emotions when you've been in situations where you are helping people to understand things. Then that can help you to formulate really clear questions.

So, whenever you're investigating a new career option, you could think, hang on a minute. A question I need to ask, in order to evaluate whether this career is right for me is, how often will I get an opportunity to feel like, I'm actually helping people to understand things? Or, or, how often does it come around? How deep is that experience? You know, so to what extent do I get to do that? And so it helps you to then, once you've identified those things that are important as patterns in your life, to turn those into questions. So that when you're researching different options in your career, you've got really good questions to ask. So that exercise is looking back, seeing patterns in your past. And, and projecting those forward into the present moment to work out what's important for you now.
As you identify some of those values you can then start to prioritize them. Now it may be that in doing that exercise you found it easy to identify the emotions, but maybe found it harder to identify the patterns to work out what was causing those emotions. And it may just be, that you don't have the vocabulary to describe, the values that are important to you.

Now this is based on a theory of working identities by a academic Herminia Ibarra. It was called how to stay stuck in the wrong career. Where she basically looked at the, the advice that is often given in relation to choosing careers and planning your careers which is work out what your values are and then pick a path and plan towards it. You know, thinking about your values now may not help you to make decisions for the future.
But also the job market is changing all the time so you can't be aware now of all the options you might have in a few years time. And so it's important to develop the skills of being able to adapt and think about your values as you go along and maybe even change your values to adapt to new environments that you want to move into and this is especially true if maybe you are changing careers. And so she proposed an alternative way of thinking about careers called Test and Learn. And Test and Learn contains three elements. The first element is crafting experiments. One of the ways in which you discover new values, is to have new experiences. And that's one of the things we often find with clients, especially at the beginning of their careers. Quite often, when we ask them what's important to you, they go. I'm not sure.

And so one of the things you might want to try and do is to try and have new experiences, and such, that, that first element of crafting experiments is to try out new things so that you learn new things about yourself. So crafting experiments. It don't have to be big things like, you know, just moving to a new country or completely changing your career. But just be changing small things about your life. Trying new things like a different route to work. Or trying to approach jobs in different ways rather than the ways you've already done them. Or maybe just try, taking your activities. Like going to an evening class to learn a subject that you've never thought about before. So that you can put yourself in new situations and find out how you respond to them. Recently there was a talk given by the UK Foreign and Commonwealth Office, the, the, the diplomatic service.
When I first started, I was really interested in Southeast Asia. And I was really looking forward to the opportunities of really, you know, using my knowledge and my awareness of Southeast Asia to work within that area. And they put me on Eastern Europe desk. And to begin with, I was really disappointed. I thought, well, hang on a minute. This isn't what I'm interested in. But I had to do because it was the job. But then she said, well actually what I found was, as I started to work on it, I realized there was an interest I, I didn't know I had. But it was only because I was forced to do it that I discovered that interest. And so, that may be the case with some of the things that are important to you. You may not know that they're important yet, because you've never been exposed to them.

And so one of the things you need to try is trying new things. Element two of the test and learn theory is shifting connections. And this is about meeting new people. Quite often, if you look at the people that you interact with on a daily basis or, or you know, on a regular basis, it tends to be within the same small group of people. And so generally speaking they know you, you know them and there's no chance for surprises in discovering new things about yourself from other people's perspectives.
So you real, don't really get to learn anything new about yourself, because you're not being able to see yourself from other perspectives. It's only the perspective that you're used to. And sometimes when you start to meet new people with different backgrounds, they see things in you that maybe haven't been seen before. Maybe you haven't even seen them in yourself. And so this shift in connects element is about consciously seeking out new communities, new people, different relationships. That'll help you to be able to see yourself in a different way. And so it might be. As I said, something that you combine with crafting experiments. Like going to a night class or an evening class or taking a different course.

And it's not so much about the subject matter that you're learning. It's about the new people that you're coming into contact with. It might be taking up new social activities. So that you can come into contact with different people and learn new things. Have different conversations. And these people will see you in a different way. They don't come with the past baggage of they know what you're like. And so its a chance for sometimes to experiment with being a different person.
The final element of this is making sense. It's no good just doing all these things if you don't learn something from them. And so in the same way that we use the lifeline exercise to reflect back on your past experiences and to think well what can I learn from those. What are the patterns. What are the things that I can pick up on and the values that I can identify? You need to then do the same for these new experiences that you're having. To look back and say, well, what does it actually mean? Did I enjoy this? Could I imagine myself enjoying it more in the future? Could I imagine myself taking on different roles and maybe my values being different? And so, that's one of the things that's, that's part of this, is to build that reflection into new activities. And this isn't goo, this isn't just for when you're considering a career change.

This is useful throughout your career, even when you're in a job in an organization and you know you're going to stay there. These are good things to do. And we'll come to this in the, in the, one of the future weeks when we actually look at what it takes to be successful within your career. And also, when we look at networking and the values of networking is, is it helps you to develop and to be aware of new opportunities. It helps you to grow and develop in your professional development and so it's a useful thing to, to get in the habit of doing. Not just the doing new things but the reflecting on them so that you can actually learn more quickly. And so what we'd like you to do, as an exercise, is to go away, and jus, and pick something new that you're going to do.
So it might be, trying a new experience. Could be something small, could be something big, but try something new and think about what you've learned from it. Or maybe pick out new people to go and talk to. You may want to find some people that you maybe wouldn't normally associate with. And go and talk to them. And find out about them. And see what you learn from how you behave towards those people. And then think about what you might have learned from it.

Enhance Your Career and Employability Skills - Understanding your values

What are career values?

• Values are a way of describing what is important to you about your work.
• They are linked to the rewards you get from your work, the contributions you want to make within your work and the meaning that your work has for you.
• They represent needs that you have that might be satisfied by your work.
• Values drive your motivation and your behaviour. If you value something highly, you will put in more effort, make bigger sacrifices and overcome bigger obstacles in order to obtain it.
• Some of our innate values will come from our personalities, from our parents, our upbringing and our cultural background. Other values may emerge or develop over time as a result of our experiences.

What are the benefits of thinking about values?

• Clear values help you to ask the right questions. If you know what is important to you for your future career, you can gather specific and relevant information about your career options rather than relying on what other people think might be important.
• Clear values help you to make difficult decisions. If you know what is important, you can balance appropriately all the factors that might determine your future career success and satisfaction. This means you are less likely to make decisions you regret in your career.
• Clearer values help you to cope better with change and uncertainty. If you know what is important, you can make decisions and take actions even when you don’t have all the information you would like or if the outcomes are uncertain. Clear values can act as a compass.
• Clear values help you to make strong impressions. If you have a clear sense of what is important, it is much easier to express that to other people. This helps them to understand you faster and helps you to have more impact in social situations.
• Clear values help you to understand other people’s values. If you know what is important to you, it increases your understanding of what is important to others, both individuals and organisations. This will help you to anticipate potential fit or conflict between your values and other values. Being aware of any conflict between an organisation’s values and your own can help you to make better choices about whether to stay or leave.
• Clear values help you to be proactive in shaping your role. If you have clearly aligned motivations, you can more readily adapt yourself to suit your role and adapt your role to suit you, whilst still providing benefits to your organisation. 

How do you know what is important?

• Some of your values may be conscious and explicit, which means you can articulate your values if someone asks you what they are. Try the What Am I Like? exercise to explore how many of your values are conscious and explicit.
• Other values may be implicit or unconscious and may be revealed by your behaviours, your responses to the things that happen to you and the choices you make.
• To increase your chances of obtaining the benefits of clearer values, you need to make as many of your values as possible conscious and explicit.
• You need to be able to reflect on your experiences in order to convert implicit values into explicit values.
• People sometimes have difficulty identifying their values because
• they have not had a sufficient range of experiences in order to reveal their implicit values
• they haven’t reflected sufficiently on their experiences in order to recognise their implicit values
• Our emotions are signals about whether or not our needs are being met. Negative emotions are linked with unmet needs and positive emotions with met needs. Therefore, our emotional responses to different situations can reveal our needs and, so our values.

Child Nutrition and Cooking - Cooking Demonstrations

Because eggs contain all of the essential amino acids (building blocks of protein) in sufficient quantities, they are considered to be a “complete” source of protein. Eggs are also relatively high in cholesterol, so they shouldn’t be eaten in excessive amounts. For healthy individuals, and eaten in moderation, eggs can be a delicious part of a balanced meal.

Most brands of olive oil, expensive or not, contain monounsaturated (good) fats and polyphenols which promote heart health. If you want, you can buy a more expensive olive oil to use for your salad, and a cheaper olive oil to use for other purposes.

Because so many food companies are competing for our food dollars, food marketing has become extremely sophisticated and billions of dollars are spent every year on marketing alone.

The opposite is true -- In the US, there are no laws governing the nutritional content of foods marketed to young children. This is one of the reasons why more screentime is correlated with higher rates of childhood obesity.

Consumers often feel as if they have many choices when shopping for food because manufacturers can disguise one base product (corn) as many different options. Food producers feel the need to market their products aggressively in order to stay afloat in a competitive marketplace.

The foods listed in the first three lists are high in nutritional value, unprocessed and will last for at least a week to several months (rice, lentils and dried beans.) The foods listed in the last answer choice are relatively high in unhealthy fat, sugar and/or salt and because these foods are highly processed, they are lower in healthful nutrients like fiber, vitamins and minerals. While these foods can be eaten occasionally as treats, they would not be very helpful in preparing healthy, nutritious meals.

Food gives our bodies the energy we need to grow, strengthen, maintain and also to repair damage. It also fuels our brain so that we can think.

Benefits of stocking the kitchen pantry:
 - A stocked kitchen pantry promotes home-cooking which is healthier than eating out
 - Having different ingredients on hand allows you to experiment with new dishes and combinations
 - Planning ahead for cooking saves time and money

The naturally occurring nutrients in food are the primary reason why pests (like molds, for example) will attack food, causing it to spoil. When foods are processed, many of these naturally occurring nutrients are stripped so that foods will last longer on a grocery store shelf. This is one of the reasons why processed, refined bread will last longer than bread that’s baked on a small scale from whole food ingredients. Even though synthetic nutrients are often added back to the processed end product, the nutritional value of the original food is not maintained through processing.