Which type of message does a receiver application use to signal its intension to join a particular source by using SSM?

While IGMPv3 reports are part of the IGMPv3 protocol, the SSM join process specifically depends on the IGMPv3 source-filtering capability defined in the query mechanism, not on IGMPv3 reports alone, which are a general membership response.

IGMPv2 reports cannot be used for SSM joins because IGMPv2 has no source address field in its message format and only supports any-source multicast (ASM) group membership.

IGMPv3 introduces the source-specific join mechanism where a receiver signals its intent to receive traffic from a specific (S,G) pair - this source filtering capability is absent in IGMPv1 and IGMPv2, making IGMPv3 the exclusive protocol for SSM channel membership signaling.

IGMPv2 queries are router-initiated messages that poll hosts for group membership but lack source-specific filtering support, making them incompatible with the SSM model.