C++ definition

Implementation of PIM-DM protocol (RFC 3973).

PIM-DM is a multicast routing protocol which is designed for networks where the receivers are densely distributed. PIM-DM initially floods the multicast datagrams to all areas of the network. If some areas of the network do not have group members, then they will be pruned off the forwarding tree.

The prune state of a branch must be confirmed periodically, otherwise the forwarding restarts automatically. The router can also cancel the prune by sending a Graft message.

The module must access the ~PimInterfaceTable and ~PimNeighborTable modules, their path is given as the pimInterfaceTableModule and pimNeighborTableModule parameters.

Other parameters are timer values from the specification. They should not be modified except for testing purposes.

Inheritance diagram

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Used in compound modules

Name	Type	Description
Pim	compound module	Implements the Protocol Independent Multicast (PIM) routing protocol for IP multicast. This module integrates both PIM-DM (Dense Mode) and PIM-SM (Sparse Mode) implementations, using a splitter to direct packets to the appropriate mode based on interface configuration. PIM builds distribution trees for efficient multicast data delivery across IP networks.

Extends

Name	Type	Description
SimpleModule	simple module	Base module for all INET simple modules.

Parameters

Name	Type	Default value	Description
displayStringTextFormat	string	""	Determines the text that is written on top of the submodule, supports displaying pars, watches, and module-specific information
interfaceTableModule	string
routingTableModule	string
pimInterfaceTableModule	string
pimNeighborTableModule	string
triggeredHelloDelay	double	uniform(0s,5s)
helloPeriod	double	30s	"Hello_Period: Periodic interval for hello messages"
holdTime	double	3.5 * helloPeriod	"The Hold Time in the Hello Message should be set to a value that can reasonably be expected to keep the Hello active until a new Hello message is received. On most links, this will be 3.5 times the value of Hello_Period."
pruneInterval	double	180s	"The Prune Timer expires, indicating that it is again time to flood data from S addressed to group G onto interface I."
pruneLimitInterval	double	210s	"t_limit: Used to prevent Prune storms on a LAN"
overrideInterval	double	2.5s	"J/P_Override_Interval: Short time after a Prune to allow other routers on the LAN to send a Join"
propagationDelay	double	0.5s
graftRetryInterval	double	3s	"Graft_Retry_Period: In the absence of receipt of a GraftAck message, the time before retransmission of a Graft message"
sourceActiveInterval	double	210s	"SourceLifetime: Period of time after receiving a multicast message a directly attached router will continue to send State Refresh messages"
stateRefreshInterval	double	60s	"RefreshInterval: Interval between successive state refresh messages"
assertTime	double	180s	"Assert Time: Period after last assert before assert state is timed out"

Properties

Name	Value	Description
class	PimDm
display	i=block/network2

Gates

Name	Direction	Size	Description
ipIn	input
ipOut	output

Signals

Name	Type	Unit	Description
sentHelloPk	cPacket
sentJoinPrunePk	cPacket
rcvdStateRefreshPk	cPacket
rcvdHelloPk	cPacket
rcvdJoinPrunePk	cPacket
sentGraftPk	cPacket
rcvdGraftPk	cPacket
sentAssertPk	cPacket
sentGraftAckPk	cPacket
rcvdAssertPk	cPacket
rcvdGraftAckPk	cPacket
sentStateRefreshPk	cPacket

Source code

//
// Implementation of PIM-DM protocol (RFC 3973).
//
// PIM-DM is a multicast routing protocol which is designed
// for networks where the receivers are densely distributed.
// PIM-DM initially floods the multicast datagrams to all areas
// of the network. If some areas of the network do not have
// group members, then they will be pruned off the forwarding tree.
//
// The prune state of a branch must be confirmed periodically,
// otherwise the forwarding restarts automatically. The router
// can also cancel the prune by sending a Graft message.
//
// The module must access the ~PimInterfaceTable and ~PimNeighborTable
// modules, their path is given as the `pimInterfaceTableModule` and
// `pimNeighborTableModule` parameters.
//
// Other parameters are timer values from the specification.
// They should not be modified except for testing purposes.
//
simple PimDm extends SimpleModule
{
    parameters:
        @class(PimDm);
        @display("i=block/network2");
        string interfaceTableModule;
        string routingTableModule;
        string pimInterfaceTableModule;
        string pimNeighborTableModule;

        volatile double triggeredHelloDelay @unit(s) = uniform(0s,5s);
        double helloPeriod @unit(s) = 30s; // "Hello_Period: Periodic interval for hello messages"
        double holdTime @unit(s) = default(3.5 * helloPeriod); // "The Hold Time in the Hello Message should be set to a value that can reasonably be expected to keep the Hello active until a new Hello message is received.  On most links, this will be 3.5 times the value of Hello_Period."
        double pruneInterval @unit(s) = 180s; // "The Prune Timer expires, indicating that it is again time to flood data from S addressed to group G onto interface I."
        double pruneLimitInterval @unit(s) = 210s; // "t_limit: Used to prevent Prune storms on a LAN"
        double overrideInterval @unit(s) = 2.5s; // "J/P_Override_Interval: Short time after a Prune to allow other routers on the LAN to send a Join"
        double propagationDelay @unit(s) = 0.5s;
        double graftRetryInterval @unit(s) = 3s; // "Graft_Retry_Period: In the absence of receipt of a GraftAck message, the time before retransmission of a Graft message"
        double sourceActiveInterval @unit(s) = 210s; // "SourceLifetime: Period of time after receiving a multicast message a directly attached router will continue to send State Refresh messages"
        double stateRefreshInterval @unit(s) = 60s; // "RefreshInterval: Interval between successive state refresh messages"
        double assertTime @unit(s) = 180s; // "Assert Time: Period after last assert before assert state is timed out"

        @signal[sentHelloPk](type=cPacket);
        @signal[rcvdHelloPk](type=cPacket);
        @signal[sentGraftPk](type=cPacket);
        @signal[rcvdGraftPk](type=cPacket);
        @signal[sentGraftAckPk](type=cPacket);
        @signal[rcvdGraftAckPk](type=cPacket);
        @signal[sentJoinPrunePk](type=cPacket);
        @signal[rcvdJoinPrunePk](type=cPacket);
        @signal[sentAssertPk](type=cPacket);
        @signal[rcvdAssertPk](type=cPacket);
        @signal[sentStateRefreshPk](type=cPacket);
        @signal[rcvdStateRefreshPk](type=cPacket);

    gates:
        input ipIn;
        output ipOut;
}

File: src/inet/routing/pim/modes/PimDm.ned

---

This documentation is released under the Creative Commons license