A bundle message consists of several standard RSVP messages that are grouped into a single RSVP message.
A bundle message must contain at least one submessage. A submessage can be any RSVP message type other than another bundle
message. Submessage types include Path, PathErr, Resv, ResvTear, ResvErr, ResvConf, and ACK.
Bundle messages are addressed directly to the RSVP neighbor. The bundle header immediately follows the IP header, and there
is no intermediate transport header.
When a device receives a bundle message that is not addressed to one of its local IP addresses, it forwards the message.
Bundle messages can be received, but not sent.