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#807: Apple Announces OS 10.8, OSI Layers Overview, Blu-Ray Support for OS X


So, it’s that time of year again…the time of year that I may look forward to more than the when the issue of Cat Fancy hits my doorstep. I am talking about the Hippo’s annual Best of voting for 2012.

We here at Small Dog feel that we do the best of anyone in the Manchester, NH area for service and support. We would love to have our loyal readers know that their vote does count and that if you have had reason to use our award-winning service—and you feel that we deserve some recognition—we would love to have you fill out one of the surveys and fill in our name on entry #125: “Thing we forgot to ask about.” Please put “Best Computer Service Shop – Small Dog Electronics” and then the fine people at Hippo Press will do the rest.

Fill out the survey here.

I do hope that we can win, but I know that I can only do one entry (that’s what the rules state), so I will have my cat do one as well. He has never had anything serviced there, but don’t tell them that.

Thanks for your support! And now on to the technical stuff…

  Apple Announces OS 10.8 "Mountain Lion"  

Apple announced last week that the next release of OS X, dubbed “Mountain Lion,” will be released this summer. Ever lessening the gap between OS X and iOS, Mountain Lion adds a few features and streamlines several others.

One example is iCal, which will be renamed Calendar. Rather than have a To-Do list as part of Calendar, Apple has added Reminders and moved the To-Do list there. Now there is a one-to-one match between where your information is stored on your iPhone and on your Mac. Same goes for Notes; no longer part of Mail, Notes is now its own application similar to how it is in iOS. You don’t have to search for “where did my notes go?” after syncing your data.

Another addition is Messages, which updates iChat to include iMessage functionality. You will be able to chat with iOS users directly using the same program you use to chat with AOL, Jabber, Google, and Yahoo! subscribers. Further, messages will be synchronized across devices, so there’s no more “where was that message with that phone number?”

Game Center has been added to OS X, so you have the same achievements and leader boards as on your iOS device. More Mac game developers are coming up with versions for both platforms, so now you will be able to share your scores between them.

Finally, a sharing feature many have been looking forward to: AirPlay Mirroring. If you have ever used an iPad to share your screen with a second generation Apple TV, Mountain Lion will give you this same feature.

Releasing a new OS so soon after Lion seems to be setting a new trend—is Apple now going to release smaller, annual updates? Instead of releasing a new operating system every two years for $129, perhaps they are now going to update more frequently for $29.99 (but don’t quote me on that). Using the App Store for distribution certainly makes it easier to obtain the software—no more driving to the local store or ordering online and waiting a few days—as well as lessens the environmental footprint.

  Advanced Networking: OSI Layers Overview  

In the beginning of networking, when ARPANET was still in its infancy, the collaboration that was necessary to make communication work smoothly between computers was built upon the RFC (Request for Comment) model. In building ARPANET, many of the most talented computer scientists of the time (circa 1969) started creating informal documents to share ideas on how networking should function and how connections should be managed.

To make networking universal and non-proprietary, the OSI model was established. OSI (Open System Interconnection) is considered to be the basis of TCP/IP and networking as it is deployed today. The OSI model consists of seven layers describing the functions and elements of a network and how they should all interact. The seven layers are Physical, Data Link, Network, Transport, Session, Presentation and Application. Each layer plays an important part in how data is sent and received on our networks of today.

The first layer of the OSI model, Physical, describes the aspects of the physical connection, be it voltages over copper to wavelength of light emitted in fiber-optic connections. It is responsible for establishing connections and terminating them too.

Layer 2, the Data Link layer, is responsible for the transmission between network nodes. The Data Link layer of the OSI model has two sub-layers, LLC and MAC. The Media Access Control, or MAC sub-layer, makes sure that the received frame was meant for a specific machine by verifying that the MAC was encoded within the frame. The LLC (Logical Link Control) sub-layer provides the tolerance for running several different protocols on one network medium. It also helps provide flow control as well as error management.

The Network Layer is responsible for the routing of data, logical addressing, datagram encapsulation and it too helps in error handling. Logical addressing in the network layer is based on the IP protocol from the TCP/IP suite. The addressing provided by IP (Internet Protocol) is also used in the routing at this layer.

Layer 4, Transport, makes sure data can be sent reliably from the sending node to the destination. It is at this layer that acknowledgement, or ACK, becomes part of the communication. An ACK is simply the step of the receiving node sending an acknowledgement that it has received the complete message. If no ACK is sent, depending on other factors, the sending node may choose to retransmit the message.

The Session Layer is the 5th layer of the OSI model. The Session Layer controls the timing of transmission and who will send versus who will receive at any given time. It is responsible for the integrity of the connection between the nodes. The Session Layer determines speed of data transmission based on other attributes from lower layers. Depending on the physical connection, it is the session layer that will decide if transmission will be simplex, full duplex or somewhere in between.

Layer 6, Presentation, is responsible for the how the data is encoded. Presentation takes the information from the Application Layer (layer 7) and breaks the data down into ASCII or EBCDIC language. It is the layer responsible for the syntax of the communication, as well as the encryption and compression of the data to be sent over the network.

Lastly, the Application Layer is the function of what you want the network to do. The protocols of HTTP, FTP, SMTP, POP and many others determine what data will be assembled by the lower levels and sent across the network to provide the outcome you plan for.

While this is by no means a comprehensive list of what each layer does, it is because of the RFC and OSI model that these defined layers were developed to regulate and standardize communications over networks.

Image source

  VLC to Provide Blu-Ray Support for OS X  

VideoLan, developers of the popular (and free) VLC video player, announced that their 2.0 version for OS X will have some exciting new features. It will use an interface similar to iTunes, have a full-screen mode in Lion, and if you have the right hardware, allow unprotected Blu-ray playback.

OS X has no built-in Blu-ray support—you can’t just connect a Blu-ray drive to your Mac and play movies on it. You have always been able to use a Blu-ray drive for data storage, and you can create a Blu-ray movie disc on a Mac, you just can’t play it back without using a different device. There have been other attempts at Blu-ray playback, but so far none have been reliable. Mac Blu-ray Player touts itself as “the first universal media player for Mac and PC in the world,” but reviews for it are anything but positive.

VLC has been known for years as THE cross-platform player. No matter what you try to play, VLC “just works.” QuickTime, Windows Media, MKV, and even movies with subtitles are supported. Now they are adding Blu-ray support to the list, making it the complete solution.

Update! When this article was written, VLC was still in beta. Last Friday, VLC released version 2.0.0. Note that the Blu-ray support is listed as “experimental” (menus are currently disabled) but the basic support is there. Good news all around—it has better integration with Lion but still supports Leopard and PPC users.

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