omnetpypy.front_end.channel

This module implements the Channel() class, which implements advanced connectivity between ports in the simulation.

class omnetpypy.front_end.channel.Channel(name, identifier=None, delay=None, loss_prob=None)[source]

Bases: SimulatedEntity

Channels are used to apply operations on messages travelling between connected ports. They can apply noise, delays, losses, and other custom operations to the messages.

Channels always have two ports, named “A” and “B”. The channel forwards messages from port “A” to port “B”, and vice versa, after applying the specified delay and loss probability.

Subclasses can override the methods process_message() to apply more complex and asymmetric operations on the messages passing through the channel.

Parameters:

namestr: The name of the channel. This name should be unique within the simulation.
identifierint or None, optional: The identifier of the channel. This identifier should be unique within the simulation. If None, the identifier will be automatically generated.
delayfloat or None, optional: The delay to be applied to the messages passing through the channel. If None, no delay is applied.
loss_probfloat or None, optional: The probability of loss to be applied to the messages passing through the channel. If None, no loss is applied.

Attributes:

delayfloat or None: The delay to be applied to the messages passing through the channel. If None, no delay is applied.
loss_probfloat or None: The probability of loss to be applied to the messages passing through the channel. If None, no loss is applied.

apply_loss(message, port_name)[source]

Apply loss to the message, based on an arbitrary loss probability distribution.

Parameters:

messageMessage: The message to be delayed.
port_namestr: The port from which the message was received.

Returns:

bool: True if the message should be lost, False otherwise.

generate_delay(message, port_name)[source]

Generate a delay for the message, based on an arbitrary delay distribution.

Parameters:

messageMessage: The message to be delayed.
port_namestr: The port from which the message was received.

Returns:

float or None: The delay to be applied to the message. If None or zero, the message will be sent immediately.

handle_message(message, port_name)[source]

Handle a message received from a port. First, it processes the message by calling the method process_message(), then it applies the optional delay and loss probability, and finally it sends the message out of the other port (if not lost).

Parameters:

messageMessage: The message to be handled.
port_namestr: The port from which the message was received.

process_message(message, port_name)[source]

Process a message received from a port. By default, this method does nothing and returns the message as is. Subclasses can override this method to apply more complex operations on the messages passing through the channel.

Parameters:

messageMessage(): The message to be processed.
port_namestr: The port from which the message was received.

Returns:

Message() or None: The message to be sent to the connected port, or None if the message should be dropped.