Designing for Fast Networks

• Designing for Fast Networks (finish)
  • Resource Reservation
  • RSVP
• Spring '97 ICS 691 course
  • Papers
  • Presentations
  • Projects

Monday Dec 8th: Prof. Ned Weldon, EE/AdTech, on Startups and on ATM testing.

Bounded-Delay

• Example: Video/Audio playback
• Receiver can buffer to mask delay variations
• Buffer size corresponds to maximum delay variation
• Can sometimes guarantee CBR, other times not (e.g. MPEG)
• Can usually adapt to different maximum delay variations
• Might be able to retransmit within maximum delay
• May be able to adapt to available bandwidth (e.g. by lowering quality)

Traditional

• Available Bit Rate (ABR)
• Whole range of delay requirements:
  • Telnet
  • NFS
  • WWW
  • FTP
  • e-mail
  • usenet
• Data corruption (loss) not acceptable
• Adapts to available bandwidth: congestion control

RSVP

• Work in progress (IETF)
• Specifying the application's needs: flowspec
• Network decision: admission control
• Communication: signaling

Flowspec

• Analogous to ATM QoS
• Rspec: requested service (e.g. how much delay)
• Tspec: traffic characteristics.
  Leaky bucket:
  • rate r
  • maximum buffer b

Admission Control

• must make yes/no decision
• need suitable algorithm for guaranteed service
• could use statistics for predictive service
• after flow is admitted, might be policed to insure it obeys its Tspec

RSVP Signaling

• connectionless
• soft state in the routers
• reservation is terminated after 60 seconds if not renewed
• reservation increases can fail gracefully
• receiver-controlled signaling
• supports multicast
• sender sends PATH with Tspec every 30 seconds
• receiver(s) reverse the path and send RESV for Tspec

Summary

• Latency becomes relatively large, network is unresponsive
• Network throughput becomes comparable to memory bus throughput
• Avoid memory-to-memory data transfers
• As throughput and user base grow, new applications appear
• New service models
• Reservations and guarantees

ICS 691

• prerequisite: 651
• no textbook
• text material: published papers
• student presentations, in-class discussion
• projects: student-initiated
• no homeworks, no exams

ICS 691: Topics

• Layers 1-5 of ISO stack
• Protocols, including Internet
• Algorithms
• Implementation
• Other Issues:
  • Cryptography
  • Net Commerce
  • Distributed Systems
  • ...

ICS 691: Presentations

• published papers
• projects
• software artifacts
• standards
• ...

ICS 691: Projects

• student initiated
• instructor initiated
• focus on:
  • learning
  • hands-on experience
  • interests