| For unicast transmission, there will be a single destination host but there may be multiple senders; RSVP can set up reservations for multipoint to single point transmission. |
| Multicast distribution forwards a copyof each data packet from a sender Si to every receiver Rj; a unicast distribution session has a single receiver R. Each sender Si may be running in a unique Internet host, or a single host may containmultiple senders, distinguished by generalized source ports. |