Sys Nica

Monday, July 17, 2017

The OSI Model's Seven Layers Defined and Functions Explained

Summary

The Open Systems Interconnect (OSI) model has seven layers. This article describes and explains them, beginning with the 'lowest' in the hierarchy (the physical) and proceeding to the 'highest' (the application). The layers are stacked this way:

Application
Presentation
Session
Transport
Network
Data Link
Physical

PHYSICAL LAYER

The physical layer, the lowest layer of the OSI model, is concerned with the transmission and reception of the unstructured raw bit stream over a physical medium. It describes the electrical/optical, mechanical, and functional interfaces to the physical medium, and carries the signals for all of the higher layers. It provides:

Data encoding: modifies the simple digital signal pattern (1s and 0s) used by the PC to better accommodate the characteristics of the physical medium, and to aid in bit and frame synchronization. It determines:
- What signal state represents a binary 1
- How the receiving station knows when a "bit-time" starts
- How the receiving station delimits a frame
Physical medium attachment, accommodating various possibilities in the medium:
- Will an external transceiver (MAU) be used to connect to the medium?
- How many pins do the connectors have and what is each pin used for?
Transmission technique: determines whether the encoded bits will be transmitted by baseband (digital) or broadband (analog) signaling.
Physical medium transmission: transmits bits as electrical or optical signals appropriate for the physical medium, and determines:
- What physical medium options can be used
- How many volts/db should be used to represent a given signal state, using a given physical medium

DATA LINK LAYER

The data link layer provides error-free transfer of data frames from one node to another over the physical layer, allowing layers above it to assume virtually error-free transmission over the link. To do this, the data link layer provides:

Link establishment and termination: establishes and terminates the logical link between two nodes.
Frame traffic control: tells the transmitting node to "back-off" when no frame buffers are available.
Frame sequencing: transmits/receives frames sequentially.
Frame acknowledgment: provides/expects frame acknowledgments. Detects and recovers from errors that occur in the physical layer by retransmitting non-acknowledged frames and handling duplicate frame receipt.
Frame delimiting: creates and recognizes frame boundaries.
Frame error checking: checks received frames for integrity.
Media access management: determines when the node "has the right" to use the physical medium.

NETWORK LAYER

The network layer controls the operation of the subnet, deciding which physical path the data should take based on network conditions, priority of service, and other factors. It provides:

Routing: routes frames among networks.
Subnet traffic control: routers (network layer intermediate systems) can instruct a sending station to "throttle back" its frame transmission when the router's buffer fills up.
Frame fragmentation: if it determines that a downstream router's maximum transmission unit (MTU) size is less than the frame size, a router can fragment a frame for transmission and re-assembly at the destination station.
Logical-physical address mapping: translates logical addresses, or names, into physical addresses.
Subnet usage accounting: has accounting functions to keep track of frames forwarded by subnet intermediate systems, to produce billing information.

Communications Subnet

The network layer software must build headers so that the network layer software residing in the subnet intermediate systems can recognize them and use them to route data to the destination address.

This layer relieves the upper layers of the need to know anything about the data transmission and intermediate switching technologies used to connect systems. It establishes, maintains and terminates connections across the intervening communications facility (one or several intermediate systems in the communication subnet).

In the network layer and the layers below, peer protocols exist between a node and its immediate neighbor, but the neighbor may be a node through which data is routed, not the destination station. The source and destination stations may be separated by many intermediate systems.

TRANSPORT LAYER

The transport layer ensures that messages are delivered error-free, in sequence, and with no losses or duplications. It relieves the higher layer protocols from any concern with the transfer of data between them and their peers.

The size and complexity of a transport protocol depends on the type of service it can get from the network layer. For a reliable network layer with virtual circuit capability, a minimal transport layer is required. If the network layer is unreliable and/or only supports datagrams, the transport protocol should include extensive error detection and recovery.

The transport layer provides:

Message segmentation: accepts a message from the (session) layer above it, splits the message into smaller units (if not already small enough), and passes the smaller units down to the network layer. The transport layer at the destination station reassembles the message.
Message acknowledgment: provides reliable end-to-end message delivery with acknowledgments.
Message traffic control: tells the transmitting station to "back-off" when no message buffers are available.
Session multiplexing: multiplexes several message streams, or sessions onto one logical link and keeps track of which messages belong to which sessions (see session layer).

Typically, the transport layer can accept relatively large messages, but there are strict message size limits imposed by the network (or lower) layer. Consequently, the transport layer must break up the messages into smaller units, or frames, prepending a header to each frame.

The transport layer header information must then include control information, such as message start and message end flags, to enable the transport layer on the other end to recognize message boundaries. In addition, if the lower layers do not maintain sequence, the transport header must contain sequence information to enable the transport layer on the receiving end to get the pieces back together in the right order before handing the received message up to the layer above.

End-to-end layers

Unlike the lower "subnet" layers whose protocol is between immediately adjacent nodes, the transport layer and the layers above are true "source to destination" or end-to-end layers, and are not concerned with the details of the underlying communications facility. Transport layer software (and software above it) on the source station carries on a conversation with similar software on the destination station by using message headers and control messages.

SESSION LAYER

The session layer allows session establishment between processes running on different stations. It provides:

Session establishment, maintenance and termination: allows two application processes on different machines to establish, use and terminate a connection, called a session.
Session support: performs the functions that allow these processes to communicate over the network, performing security, name recognition, logging, and so on.

PRESENTATION LAYER

The presentation layer formats the data to be presented to the application layer. It can be viewed as the translator for the network. This layer may translate data from a format used by the application layer into a common format at the sending station, then translate the common format to a format known to the application layer at the receiving station.

The presentation layer provides:

Character code translation: for example, ASCII to EBCDIC.
Data conversion: bit order, CR-CR/LF, integer-floating point, and so on.
Data compression: reduces the number of bits that need to be transmitted on the network.
Data encryption: encrypt data for security purposes. For example, password encryption.

APPLICATION LAYER

The application layer serves as the window for users and application processes to access network services. This layer contains a variety of commonly needed functions:

Resource sharing and device redirection
Remote file access
Remote printer access
Inter-process communication
Network management
Directory services
Electronic messaging (such as mail)
Network virtual terminals

Source > http://tinyurl.com/jlxoju6

4 blogs, 1 site and a Facebook page

*I won't be able to manage all this once I get back on the road coming up soon and, "No" I don't let anyone assist me with content or flopping graphics, etc. I'll do my best. In many instances I'll have to supply links that I have scanned and found to be safe.

Under construction

Facebook > https://www.facebook.com/GSESN/

School lunch shaming: Inside America's hidden debt crisis

Interactive > http://money.cnn.com/2017/05/09/news/economy/school-lunch-shaming-debt-crisis/index.html

Matt Antignolo has worked in public school cafeterias for 24 years.

He's learned two key truths: Just about every kid loves pizza, and an alarming number of American youngsters still can't afford a $2.35 lunch, despite the dramatic expansion of free and reduced lunch programs.

When a student doesn't have enough money for lunch, cafeteria staff in many districts, including Antignolo's, take away the child's tray of hot food and hand the student a brown paper bag containing a cold cheese sandwich and a small milk. Some schools take away their lunch entirely.

"It's the worst part of the job. Nobody likes it," says Antignolo, who's now director of food services at the Lamar Consolidated District outside Houston.

All the other kids in the lunch line know what's going on. Getting that brown bag is the lunch line equivalent of being branded with a Scarlet Letter. It's been dubbed "school lunch shaming."

It happens across the country: 76% of America's school districts have kids with school lunch debt, according to the School Nutrition Association. The horror stories keep coming. In 2015, a Colorado cafeteria worker says she was fired for personally paying for a first grader's meal. Last year, a Pennsylvania lunch lady quit in protest after being forced to take food away from a student who was $25 in debt.

Policies vary, but many schools serve an "alternate meal," like a cheese sandwich, once a student's debt hits $15.

Last month, New Mexico banned any form of lunch shaming. The dramatic move highlighted this hidden crisis in schools and ignited a national conversation about what to do when students can't pay. The federal Department of Agriculture, which oversees school meals, is requiring that districts at least have a written policy in place by July 1.

"It's very obvious who the poor kids are in the school," says New Mexico state senator Michael Padilla, who drafted the bill to stop lunch shaming. He told NPR that he mopped the cafeteria floors in order to afford lunch as a kid.

The USDA is urging districts to stop "embarrassing" and "singling out" students who don't have enough money for lunch. On Monday, US Senator Tom Udall of New Mexico introduced a bill in Congress, the Anti-Lunch Shaming Act, to ban schools from singling children out "by requiring them to wear wristbands or hand stamps or do extra chores" if they have unpaid lunch bills.

Teacher says, 'I felt I had to do something'

Chris Robinson hopes Texas passes a similar bill to New Mexico's. Growing up in a mostly black school, Robinson was ridiculed for not having lunch money. There was a separate line for pizza at his school. He could never afford to stand in it.

Now 33, Robinson is a special education teacher in Houston. In his first year teaching a few years back, he watched a young boy go around the cafeteria collecting food scraps before the lunch period ended. He said it took all his inner strength not to cry.

Currently, 20 million young people -- about 40% of all US students -- receive free lunches, up significantly from 13 million in 2000. Robinson can see first-hand that kids are still unable to pay for food.

"I just felt I had to do something. I can't save everyone, but if I could do something about these cheese sandwiches, it would be worth it," says Robinson. He posted a video on GoFundMe, a fundraising website, asking for donations to pay off student lunch debt. He and his wife also pitched in.

The campaign raised about $700. He took it to the Fort Bend District in Sugar Land, Texas. A few days later, he received a letter in the mail from an elementary school student. It was elaborately decorated with crayon drawings of butterflies and flowers.

The note read: "Thank you for giving money to go and clear my account. My mom really appreciated [it]. My mom is really thankful. She couldn't believe it."

Complete article > http://money.cnn.com/2017/05/09/news/economy/school-lunch-shaming-debt-crisis/index.html

How to Spot a Liar: 7 Clues Anyone Can Use

1. Is her face giving it away?

You may think a smile can easily disguise your true feelings, but the expressions that flash across a liar's face will give away what she's really thinking—whether she knows it or not. Experts advise paying close attention to hard-to-hide micro-expressions; these clues are often so difficult to detect that even trained experts have trouble discerning them. But you may be able to spot a liar by the red color on her cheeks, since anxiety can cause people to blush. Other indicators of lying? Flared nostrils, lip nibbling, deep breathing, and rapid blinking, which hint that the brain is working overtime.

2. Does the body language follow the story?

It’s more important to examine a person’s entire demeanor, as there’s no one feature that’s apt to give away a liar. Honesty is characterized by features that are in sync with one another—so besides posture, note the fit between face, body, voice, and speech. Like an animal avoiding detection, a liar may pull his arms and legs inward or keep his movements to a minimum—anything to appear smaller. Liars often shove their hands behind their back because those fidgety digits might give them away.

3. How is the person smiling?

A smile can sometimes mask a person’s true feelings. Pay close attention to how a person smiles as well as other facial movements. You may be able to detect the emotions he or she is trying to hide—such as fear, anger, and disgust. A true smile will incorporate both a person’s lips and eyes.

4. How is the person speaking?

Although a change in voice can be the tip-off to spot a liar, experts say that to be sure, you should also pay attention to a person’s speech rate and breathing pattern—if either speeds up or slows down, chances are you’re not hearing the whole truth.

*For those who employ psychology into every aspect of their life will readily see that all this goes out the window when the speaker of the lie believes it themselves.

Full article > http://www.rd.com/advice/relationships/how-to-spot-a-liar/

Sunday, July 16, 2017

I updated my CV, could this be the future of CV's?

https://cv2017.blogspot.com/

Do you need someone found / Skip Trace

*I did this for a while but no more.

THE TOP TEN BEST COMPUTER SEARCHES
FOR LOCATING MISSING PERSONS

Learn What The Top Sources Are, How To Use Them Correctly And
Analize What You Get Effectively For Successful Skip Tracing
By Ralph D Thomas
Back in the 1960's and 1970's you really had to be a very good investigator in order to conduct hardcore missing persons investigations. There where not any computerized searches like we have today and central repositories of various types of records didn't exist like they do today. As good as all these new high tech skip trace tools are, newer skip tracers and missing persons investigators seem to have a great deal of misconception about them. In and of themselves, they are not investigations and just because you gain access to computer searches doesn't mean that you are going to be able to find anyone anywhere. Oh you will find a few skips now and then but your strick out rate is going to be high. Computer searches have limitations and some people know enough to keep out of certain database files forever outguessing and baffling the unreasoned investigator. It is only when you approach the use of online searches as a mere hit-or-miss tool and not an investigation unto itself that the missing persons investigator will start to become successful. Moreover, there is often hidden information in those files that doesn't give you an address but will open keys to other avenues you most utilize to up your home run score. Keeping that approach in mind, I'd like to review the top databases and online searches for locating missing persons in resending order.

NUMBER ONE
SOCIAL SECURITY TRACE
The Social Security Trace is likely the most effective search used to locate a missing person. It requires that you have the social security number which is used as the input information. This search is actually the top portion of a credit bureau file containing the name and address information. The reason it is the most effective search is because address updates often end up in this database without people realizing that various activity will trigger new address information input into credit bureaus. These reasons could include:

A)extension of credit
B) as a direct result of filling out an employment application
C) As a direct result of filling out an application to rent an apartment.
D) AS a direct result of a loan company or bank attempting to collect a debt (they skip traced the subject, located the subject and provided the new address to a credit bureau network)
E) As a direct result of applying for insurance.
F) As a direct result of applying for various utilities such as water, gas or electric (Many utility companies are now running credit bureaus to determine user deposits).
G) As a direct result of an investigator or other professional using the National Identifier as a trace on the subject to either obtain the SSN number or verify identity information.

It's important to realize that there are about 200 million credit bureau files that are consistently being instantly updated by hundreds of thousands of input updates weekly.

Social Security Tracing is unregulated by the Fair Credit Reporting Act which means that it is not a restricted search and does not require permissible purposes under the federal law. However, some state laws have superceded federal law. In a few state such as California, a Social Security Trace requires that a notification footer be created every time a Social Security Trace is run. What that means is that a record is kept on the bottom portion of the credit bureau file of the company running the SSN Trace.

When using Social Security Tracing, it is important to understand that there are three credit bureaus (TRW, CBI and Trans Union) that offer such a trace. In order to make a more wider geographical sweep of credit bureau headers, it is usually best to run more than one source.

One of the added features of an SSN tace is the fact that you'll obtain other information that can be helpful.

1) Death Claims Notification
All the credit bureaus subscribe to the Social Security Administration's National Death Claims Index. This is a database of people who have filed claims on an SSN number for death benefits. The original purpose of this extra feature is to insure against credit fraud by using a dead person's SSN number.

2) Multiple Social Security Numbers
When investigators frequency run an SSN Trace on various types of people who are under investigation, they soon notice that many of these people are using more than one SSN number. Sometimes this is a clerical error on the part of people who input information to credit bureaus. More often, however, this is a result of the subject attempting to use a secondary SSN number to cover his trails. Nine times out of ten, this is instantly spotted and tagged with the subject's other file.

HERE IS WHAT A SAMPLE SSN TRACE LOOKS LIKE:

Scanning ... Source #1 FOR ... 123-45-6789

DATE: 11/06/87 TIME: 13:20

* SOCIAL SECURITY NUMBER TRACE * 123-45-6789
NAME/SPOUSE SSN OWNER
ADDRESS ADDR RPT DATE

1. CONSUMER, JOHN D SUBJECT
3142 TAG DR., KANSAS CITY. KANSAS 66102 09/84

2. CONSUMER, JOHN D SUBJECT
178 COLDSPRING LN., DALLAS, TX 75228 10/87

Scanning ... Source #2 FOR ... 123-45-6789

M1 OF 4 NM-CONSUMER,JOHN CA-3142,TAG,DR,KANSAS CITY,KA,66102 ,04/84
SS-123-45-6789 AGE 46

M2 OF 4 NM-CONSUMER,JOHN,D CA-441,VINE,ST,TAMPA,FL,33604,07/86
SS-123-45-6789

M3 OF 4 NM-CONSUMER,JOHN CA-123,SANDY,LN,DETROIT,MI,48229,11/86
FA-4162,MCLEAN,DR,CINCINNATI,OH,45230,7/87
SS-123-45-6789 AGE 46

M3 OF 4 NM-SMITH,JOHN CA- 178 COLDSPRING,LN,DALLAS,TX,75228,9/87
FA-123,SANDY,LN,DETROIT,MI,48229,9/86
SS-123-45-6789 AGE 45

How to Interpret the above

M1 OF 4 ... is interpreted as Message 1 of 4 name/address records
NM- ... is interpreted as Lastname,Firstname
CA- ... is interpreted as Current Address
,mm/yy ... is interpreted as the month/year name/address was entered as data
FA- ... is interpreted as Former Address
SS- ... is interpreted as the associated Social Security Number
AGE- ... is interpreted as reported age of the subject

Full article > https://www.pimall.com/nais/n.ten.ss.html

What is BIOS (Basic Input/Output System)

BIOS may refer to any of the following:

1. Short for Basic Input/Output System, the BIOS (pronounced bye-oss) is a ROM chip found on motherboards that allows you to access and set up your computer system at the most basic level. In the picture below, is an example of what a BIOS chip may look like on your computer motherboard. In this example, this is a picture of an early AMIBIOS, a type of BIOS manufactured by the AMI. Another good example of a BIOS manufacturer is Phoenix.

The BIOS includes instructions on how to load basic computer hardware and includes a test referred to as a POST (Power On Self Test) that helps verify the computer meets requirements to boot up properly. If the computer does not pass the POST, you will receive a combination of beeps indicating what is malfunctioning within the computer.

The four main functions of a PC BIOS

POST - Test the computer hardware and make sure no errors exist before loading the operating system. Additional information on the POST can be found on our POST and Beep Codes page.
Bootstrap Loader - Locate the operating system. If a capable operating system is located, the BIOS will pass control to it.
BIOS drivers - Low level drivers that give the computer basic operational control over your computer's hardware.
BIOS or CMOS Setup - Configuration program that allows you to configure hardware settings including system settings such as computer passwords, time, and date.

2. When referring to a person BIO, BIO's is short for biography and is a term used to describe a brief description of a person. A short biography or description of people who have affected the computer industry can be found on our computer people section.

ACPI, BBS, BIO, BIOS shadow, BPB, CMOS, EFI, Firmware, Flash BIOS, FWH, Libreboot, Motherboard terms, NVRAM, PROM, UEFI

Last Reviewed: 11-Jul-2017

Article ID: 000005476

The BIOS setup program can be used to view and change the BIOS settings for the computer. To access the settings, press the F2 key after the Power-On Self-Test (POST) memory test begins and before the operating system boot starts.

If any problems occur after making BIOS setting changes (poor performance or intermittent issues), reset the desktop board to default values with these steps:

During boot, enter the BIOS setup by pressing F2.
Press F9 to set defaults.
Press F10 to save and exit.

If the system locks or will not boot after making BIOS settings changes, start a BIOS recovery as described in the Instructions for Recovery BIOS update.

BIOS Settings Glossary Version 19 (PDF)

The latest BIOS settings glossary is version 19 and includes the BIOS settings for the currently shipping desktop boards.

File name: BIOSGlossary_v19.pdf
Size: 307 KB
Date: November 2012
Version: 19

Note: PDF files require Adobe Acrobat Reader*

Version 13

Version 13 of the BIOS settings glossary is an archived glossary that includes settings for discontinued and legacy desktop boards.

7 High Tech Drones For Sale Today

http://tinyurl.com/yaj4pn77

Keep your PC Up to date

http://tinyurl.com/yaj4pn77

Newer Tech to Protect Your Health

*The days of excuses have passed.

https://www.amazon.com/

Simply because it's now manageable doesn't mean you want to manage it.

Need an ad for your business?

*When I was living in Nicaragua (Early stages) I was running ads for American and Canadian businesses. I don't speak very good Spanish yet I used various translators, back to the point.
This is a picture of a friend's house in Buffalo NY. that I just screenshot. It could be your bussiness with directions and whatever statement you wished to make.