Transport-layer protocols Internet transport services: lication g reliable. in-order unicast data link networ delive ry (TCp) data link o congestion o flow contro o connection setup be, physical i network data link a unreliable (best-effort physical unordered unicast or 受 multicast delivery: UDP o services not available application o real-time networ data link o bandwidth guarantees o reliable multicast 3: Transport Layer 3a-33: Transport Layer 3a-3 Transport-layer protocols Internet transport services: reliable, in-order unicast delivery (TCP) congestion flow control connection setup unreliable (“best-effort”), unordered unicast or multicast delivery: UDP services not available: real-time bandwidth guarantees reliable multicast application transport network data link physical application transport network data link physical network data link physical network data link physical network data link physical network data link network physical data link physical