• Reception of invalid SPM will be ignored.
• Reception of SPM with non-matching data-destination port will be ignored.
• Reception of SPMs with SPM sequence number older or equal to previous sequence number will be ignored.

]

• Reception of SPMs for new TSIs indicate a new PGM session.
• Reception of SPMs for known TSIs update the stored NLA to send NAKs.

• Reception of SPM updates the status of the Tx Window indicating lost leading packets causing NAK generation.