[PLUG] [Retitled for clarity] File sharing over a two node LAN

[Rodney W. Grimes]

> >>>>> "Richard" == Richard Owlett <rowlett at cloud85.net> writes:
> 
> Richard> On 08/10/2019 02:01 PM, Russell Senior wrote:
> >> On Sat, Aug 10, 2019 at 8:55 AM Richard Owlett <rowlett at cloud85.net> wrote:
> >> 
> >>> I have read more and made some progress ;} I am using Debian 9.8
> >>> {Stretch} with MATE desktop on two Lenovo laptops.  As I used
> >>> Networkmanager to create the ad-hoc network, I only have WEP *NOT*
> >>> WPA at the moment [but have info on doing WPA].  [see
> >>> 
> >>> https://wiki.debian.org/WiFi/HowToUse#WiFi_can_scan.2C_but_not_connect_using_NetworkManager_.28Debian_9_Stretch.29
> >>> on how to overcome a connection problem.]
> >>> 
> >>> My stated goal is file sharing on a peer-to-peer network with
> >>> exactly two nodes. The unstated purpose of chosen method is
> >>> understanding networks. Traveling down memory lane to early 60's, I
> >>> can see this as a Sophomore/Junior E.E. lab {Cornell's
> >>> B.S.E.E. program was 5 years at the time ;]
> >>> 
> >> 
> >> Nothing on wireless involves two nodes. Each station broadcasts. It's
> >> only happenstance if only two stations are receiving, it could easily
> >> be more.
> 
> Richard> IRRELEVANT to topic at hand. *MY* LAN has exactly two
> Richard> nodes. The "physical transport layer" happens to be WiFi, could
> Richard> just as well be 20mA current loop.
> >> 
> >> Did you see this?
> >> 
> >> https://wiki.debian.org/WiFi/AdHoc
> 
> Richard> Yes but it is not germane as Networkmanager was used to
> Richard> establish the connection. It does the same job but evidently
> Richard> stores its information differently.
> 
> NetworkManager is going to hide the details from you. If you want to
> learn more about how it works (referring to your "EE lab" remark), the
> AdHoc link would be better adapted to that.
> 
> >> 
> >> 
> >>> 
> >>> Since I last posted, I've discovered "Open Systems .Interconnection
> >>> (OSI) Model".
> >>> 
> >>> 
> >> Did you see this part?
> >> 
> >> https://en.wikipedia.org/wiki/OSI_model#Comparison_with_TCP/IP_model
> >> [snip long quotation]
> 
> Richard> I hadn't. But I did not see any guidance there.
> 
> The guidance is to forget about OSI except for very general conceptual
> ideas. Don't try to find an implementation. The snipped quotation refers
> to how it is "unimplementable".

About the only thing in use today in the network world that
came from the OSI work is the "7 layer model", if you want all
the usuful information from OSI, here it is:

 The seven layers of the OSI Basic Reference Model are (from bottom to top):

    The Physical Layer describes the physical properties of the various communications media, as well as the electrical properties and interpretation of the exchanged signals. Ex: this layer defines the size of Ethernet coaxial cable, the type of BNC connector used, and the termination method.

    The Data Link Layer describes the logical organization of data bits transmitted on a particular medium. Ex: this layer defines the framing, addressing and checksumming of Ethernet packets.

    The Network Layer describes how a series of exchanges over various data links can deliver data between any two nodes in a network. Ex: this layer defines the addressing and routing structure of the Internet.

    The Transport Layer describes the quality and nature of the data delivery. Ex: this layer defines if and how retransmissions will be used to ensure data delivery.

    The Session Layer describes the organization of data sequences larger than the packets handled by lower layers. Ex: this layer describes how request and reply packets are paired in a remote procedure call.

    The Presentation Layer describes the syntax of data being transferred. Ex: this layer describes how floating point numbers can be exchanged between hosts with different math formats.

    The Application Layer describes how real work actually gets done. Ex: this layer would implement file system operations. 


There, I just save you $200 and a lot of time reading, the above
is all one should ever bother with from OSI.

> Russell Senior, President
> russell at personaltelco.net
-- 
Rod Grimes                                                 rgrimes at freebsd.org