Some network apps OE-mail Internet telephone OWeb Real-time video ▣Instant messaging conference Remote login ▣Massive parallel P2P file sharing computing 口Aulti-user network ▣ games 0 ▣Streaming stored 0 video clips 2:Application Layer 4 2: Application Layer 4 Some network apps  E-mail  Web  Instant messaging  Remote login  P2P file sharing  Multi-user network games  Streaming stored video clips  Internet telephone  Real-time video conference  Massive parallel computing   