Is the Internet Ready for Multimedia?

Ahmed Helmy

University of Southern California

Is the Internet Ready for Multimedia?

• What is Multimedia?– Common: Real-time/streaming (audio/video) – More general: Multiple requirements (QoS) by

different applications– What are these requirements?

• End-to-end metrics: Reliability, Delay, Jitter, least cost!

• Aggregate metrics: Least congestion, maximum utilization, fair, minimum energy!

– Is Internet-supported emergency service MM?• Need very high priority service

• What is the Internet?– Wired– Last hop wireless (cellular, access points, space

optics and pico cells)– Mobile (continuous vs. intermittent)– Multi-hop wireless (Ad hoc)– other… !

• Different network characteristics provide different challenges for various requirements– Need to understand characteristics of these

networks• Need models for: topology, traffic, channel, mobility

…

Supply vs. Demand

• Supply– Infrastructure (e.g., ISPs,

content providers)

– Architecture/protocols• IntServ

• DiffServ

• Hybrid!

– Business and pricing models???

• Demand (those who need QoS)– Audio, video, collaborative

virtual env.– Multicast

• Dense-mode, Sparse-model, source-specific

• Inter-domain? (BGMP)• Current: PIM-SM, MDSP,

SSM !

– P2P: effect on network– New paradigms

• Ad hoc/Sensor networks• Active networks

Demand is a moving target.We need to be flexible and think ahead.What’s the next killer app.?

Are we ready? (Questions)• What does QoS mean without end-to-end

deployment of IntServ or DiffServ?

• Can we over-provide resources?– What resources? Bandwidth, computation

(servers), energy ! (sensor nets)– Can we over-provide everywhere?

• Will the solution be a hybrid approach– Over-provisioning when/where possible– QoS architecture otherwise

• What about DoS attacks?– Need fairness and isolation of misbehavior

Are We Ready? (more Qs)

• We talk about network-side QoS

• What about protocol-side QoS?

• If the network is not congested, can we guarantee protocol behavior?

• We need better approaches to design predictable protocols– Can we provide a parallel of circuit-design

CAD tools?

What about emerging networks?

• Example:– Multicast in large-scale ad hoc networks– How to rendezvous in an infrastructure-less

network?• Need to re-think bootstrap and resource discovery

• Need to re-think routing in a highly dynamic env.

• Should we think about it when we do not know how to do it in the wired network?– Good intellectual exercise that has potential

Are we ready? (Answer)

• Of course not

• We have a lot more work to do!