Network Protocols

"State machine diagram is a behavior diagram which shows discrete behavior of a part of designed system through finite state transitions. State machine diagrams can also be used to express the usage protocol of part of a system. Two kinds of state machines defined in UML 2.4 are:
(1) behavioral state machine, and
(2) protocol state machine.
The following nodes and edges are typically drawn in state machine diagram: behavioral state, behavioral transition, protocol state, protocol transition, different pseudostates. ...
Behavioral state machine is specialization of behavior and is used to specify discrete behavior of a part of designed system through finite state transitions. The state machine formalism used in this case is an object-based variant of Harel statecharts.
Behavior is modeled as a traversal of a graph of state nodes connected with transitions. Transitions are triggered by the dispatching of series of events. During the traversal, the state machine could also execute some activities. ...
Protocol state machine is a specialization of behavioral state machine and is used to express usage protocol or lifecycle of a classifier. It specifies which operations of the classifier can be called in which state and under which condition, thus specifying the allowed call sequences on the classifier’s operations. Protocol state machines express the legal transitions that a classifier can trigger." [uml-diagrams.org/ state-machine-diagrams.html]
The template "UML state machine diagram" for the ConceptDraw PRO diagramming and vector drawing software is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ software-uml

This diagram sample illustrates the cooperative vehicular delay-tolerant network operation.
"Delay-tolerant networking (DTN) is an approach to computer network architecture that seeks to address the technical issues in heterogeneous networks that may lack continuous network connectivity. Examples of such networks are those operating in mobile or extreme terrestrial environments, or planned networks in space.
Recently, the term disruption-tolerant networking has gained currency in the United States due to support from DARPA, which has funded many DTN projects. Disruption may occur because of the limits of wireless radio range, sparsity of mobile nodes, energy resources, attack, and noise." [Delay-tolerant networking. Wikipedia]
"Routing in delay-tolerant networking concerns itself with the ability to transport, or route, data from a source to a destination, which is a fundamental ability all communication networks must have. Delay- and disruption-tolerant networks (DTNs) are characterized by their lack of connectivity, resulting in a lack of instantaneous end-to-end paths. In these challenging environments, popular ad hoc routing protocols such as AODV and DSR fail to establish routes. This is due to these protocols trying to first establish a complete route and then, after the route has been established, forward the actual data. However, when instantaneous end-to-end paths are difficult or impossible to establish, routing protocols must take to a "store and forward" approach, where data is incrementally moved and stored throughout the network in hopes that it will eventually reach its destination. A common technique used to maximize the probability of a message being successfully transferred is to replicate many copies of the message in hopes that one will succeed in reaching its destination." [Routing in delay-tolerant networking. Wikipedia]
The example "Cooperative vehicular delay-tolerant network diagram" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Vehicular Networking solution from the Computer and Networks area of ConceptDraw Solution Park.

"Logical topology, or signal topology, is the arrangement of devices on a computer network and how they communicate with one another. How devices are connected to the network through the actual cables that transmit data, or the physical structure of the network, is called the physical topology. Physical topology defines how the systems are physically connected. It represents the physical layout of the devices on the network. The logical topology defines how the systems communicate across the physical topologies.
Logical topologies are bound to network protocols and describe how data is moved across the network. ...
EXAMPLE : twisted pair Ethernet is a logical bus topology in a physical star topology layout. while IBM's token ring is a logical ring topology, it is physically set up in star topology." [Logical topology. Wikipedia]
This Cisco logical computer network diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Cisco Network Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.

The vector stencils library "Logical network diagram" contains 16 symbols for drawing logical computer network diagrams.
"The logical topology ... is the way that the signals act on the network media, or the way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices. A network's logical topology is not necessarily the same as its physical topology. ...
The logical classification of network topologies generally follows the same classifications as those in the physical classifications of network topologies but describes the path that the data takes between nodes being used as opposed to the actual physical connections between nodes. The logical topologies are generally determined by network protocols as opposed to being determined by the physical layout of cables, wires, and network devices or by the flow of the electrical signals, although in many cases the paths that the electrical signals take between nodes may closely match the logical flow of data, hence the convention of using the terms logical topology and signal topology interchangeably.
Logical topologies are often closely associated with Media Access Control methods and protocols. Logical topologies are able to be dynamically reconfigured by special types of equipment such as routers and switches." [Network topology. Wikipedia]
The symbols example "Logical network diagram - Vector stencils library" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Computer and Networks solution from the Computer and Networks area of ConceptDraw Solution Park.
www.conceptdraw.com/ solution-park/ computer-and-networks