Unix Service example - Telnet no Listener

The user start a telnet session. His session is rejected as there is no listener active. This happens when the used service (in this case telnet) is not configured or started. This is the shortest msg-flow as it ends with the first choice available. This example is more about the TCP messages, use the pop-up in the ASCII below to see more information. Currently there are not that many permutations (24) as it is straight forward and also limited in amount of repetitions. Perhaps if there is interest than the intended flows are added in the future. Use the choices on the right to make different diagrams.

The generated MSG-Flow

User TCP-CL inetd
| | |
+-start-telnet
Info for start-telnet
No link information between act and comp for start-telnet
| |
|-tcp-cl-connect
Info for tcp-cl-connect
No link information between msg and prot for tcp-cl-connect
->| |
| |--SYN
Info for SYN
No link information between msg and prot for SYN
dst_port23
src_port33333
->|
| | +-no-listener-active
Info for no-listener-active
No link information between act and comp for no-listener-active
| |<--RST
Info for RST
No link information between msg and prot for RST
dst_port33333
src_port23
-|
|<--tcp-cl-failed
Info for tcp-cl-failed
No link information between msg and prot for tcp-cl-failed
-| |
+-exit-telnet
Info for exit-telnet
action exit-telnetThe telnet process was stopped.
section Visible actions
component UserRepresents an external user.
| |

You can and paste the above flow representation in a text file or in your favourite text editor using a monospace font. Ofcourse you will loose the context sensitive output and the links towards additional information.

Decission table

The decission table shows which decissions have been made so far and which to make. The header contains the choice number and the entity making the choice. The choices are shown from left (latest) to right (earlier) which make it handier to follow or adapts. All choices you could have choisen on a specific level are displayed. You can click on the description to make a different choice.

telnet-flows : The main start of a telnet flow.

Additional Generated Information

Below is the graphical representaion rendered using PlantUML Try it yourself online

Cannot render UML

You can the following url to refer to the graph. Or copy as to have it embeded in usable HTML code.

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The plain text, which can be used by some editors, is given below. Use it if you want to make edit in you favorite editor. It does not contain links as they are not supported by some editors. You can copy the text and paste it e.g. into WebSequenceDiagrams, SequenceDiagram or SwimLanes. You can also copy it for and paste it into PlantUML.