PimSm

simple module

Implementation of PIM-SM protocol (RFC 4601).

PIM-SM is a multicast routing protocol which builds a shared multicast forwarding tree rooted at a Rendezvous Point (RP) per group, and a source specific forwarding tree from the sources to the RP. It is also capable of switching to a shortest path tree, so that traffic from sources to receivers does not have to pass through the RP.

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

The 'RP' parameter specifies the address of the Rendezvous Point. Currently only one global RP is supported.

If there are multiple PIM routers on a multi-access LAN, only one of them will be responsible for forwarding datagrams to the LAN. This will be the router with the highest IP address except if all routers have designatedRouterPriority set, in which case the highest priority wins (or highest IP address on ties).

Other parameters set the time constants to the values specified in RFC 4601. They should not be changed except for testing.

Limitations:

Only one global RP is supported and it must be specified statically. PIM Bootstrap and RP discovery are not yet implemented.
Switchover to the shortest path tree is not supported.
Source specific excludes in the shared tree are not supported.

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
RP	string	""
designatedRouterPriority	int	-1
triggeredHelloDelay	double	uniform(0s,5s)
helloPeriod	double	30s
holdTime	double	3.5 * helloPeriod
joinPrunePeriod	double	60s	Period between Join/Prune messages (called t_periodic in the RFC)
defaultOverrideInterval	double	2.5s
defaultPropagationDelay	double	0.5s
keepAlivePeriod	double	210s
rpKeepAlivePeriod	double	3 * registerSuppressionTime + registerProbeTime
registerSuppressionTime	double	60s
registerProbeTime	double	5s
assertTime	double	180s
assertOverrideInterval	double	3s

Properties

Name	Value	Description
class	PimSm
display	i=block/network2

Gates

Name	Direction	Size	Description
ipIn	input
ipOut	output

Signals

Name	Type	Unit	Description
sentRegisterPk	cPacket
sentHelloPk	cPacket
sentJoinPrunePk	cPacket
rcvdHelloPk	cPacket
rcvdJoinPrunePk	cPacket
sentRegisterStopPk	cPacket
rcvdRegisterPk	cPacket
sentAssertPk	cPacket
rcvdRegisterStopPk	cPacket
rcvdAssertPk	cPacket

Source code

//
// Implementation of PIM-SM protocol (RFC 4601).
//
// PIM-SM is a multicast routing protocol which
// builds a shared multicast forwarding tree rooted at a Rendezvous Point (RP)
// per group, and a source specific forwarding tree from the sources to the RP.
// It is also capable of switching to a shortest path tree, so that traffic from
// sources to receivers does not have to pass through the RP.
//
// The module must access the ~PimInterfaceTable and ~PimNeighborTable
// modules; their path is given as the `pimInterfaceTableModule` and
// `pimNeighborTableModule` parameters.
//
// The 'RP' parameter specifies the address of the Rendezvous Point.
// Currently only one global RP is supported.
//
// If there are multiple PIM routers on a multi-access LAN, only one
// of them will be responsible for forwarding datagrams to the LAN.
// This will be the router with the highest IP address except if
// all routers have `designatedRouterPriority` set, in which case
// the highest priority wins (or highest IP address on ties).
//
// Other parameters set the time constants to the values specified
// in RFC 4601. They should not be changed except for testing.
//
// Limitations:
// - Only one global RP is supported and it must be specified statically.
//   PIM Bootstrap and RP discovery are not yet implemented.
// - Switchover to the shortest path tree is not supported.
// - Source specific excludes in the shared tree are not supported.
//
simple PimSm extends SimpleModule
{
    parameters:
        @class(PimSm);
        @display("i=block/network2");
        string interfaceTableModule;
        string routingTableModule;
        string pimInterfaceTableModule;
        string pimNeighborTableModule;
        string RP = default("");
        int designatedRouterPriority = default(-1);

        volatile double triggeredHelloDelay @unit(s) = uniform(0s,5s);
        double helloPeriod @unit(s) = 30s;
        double holdTime @unit(s) = default(3.5 * helloPeriod);
        double joinPrunePeriod @unit(s) = default(60s); // Period between Join/Prune messages (called t_periodic in the RFC)
        double defaultOverrideInterval @unit(s) = 2.5s;
        double defaultPropagationDelay @unit(s) = 0.5s;
        double keepAlivePeriod @unit(s) = 210s;
        double rpKeepAlivePeriod @unit(s) = 3 * registerSuppressionTime + registerProbeTime;
        double registerSuppressionTime @unit(s) = 60s;
        double registerProbeTime @unit(s) = 5s;
        double assertTime @unit(s) = 180s;
        double assertOverrideInterval @unit(s) = 3s;

        @signal[sentHelloPk](type=cPacket);
        @signal[rcvdHelloPk](type=cPacket);
        @signal[sentRegisterPk](type=cPacket);
        @signal[rcvdRegisterPk](type=cPacket);
        @signal[sentRegisterStopPk](type=cPacket);
        @signal[rcvdRegisterStopPk](type=cPacket);
        @signal[sentJoinPrunePk](type=cPacket);
        @signal[rcvdJoinPrunePk](type=cPacket);
        @signal[sentAssertPk](type=cPacket);
        @signal[rcvdAssertPk](type=cPacket);

    gates:
        input ipIn;
        output ipOut;
}

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