Implementing A Very Simple Protocol

Very Simple Virtual Circuit Protocol

Notes to the Writer

Goals

• Describe basic user procedure
• Begin to describe underlying architecture and components
• Talk about substrate concept

Sections

• xxx

Figures

• Application header format
• xxx

Links

• An Overview Of The SPP Substrate Architecture

Versions

• 0
  • VCI in first word of UDP payload
  • VCI is globally unique
• 1
  • VCI can change during transit as part of pkt processing

User-space pkt

• Tunnel socket appears in UDP header
• VCI is first word of UDP payload
• Payload also has timestamp (for RTT and space-time diagram)

Substrate Implementation Concepts

• Physical interfaces
• Queues
• Filters
• Line card
• Parse, Lookup, Header Format

Slowpath Implementation

• Filters for local delivery
• User-space process
  • Has VCI-MI Socket map; i.e., M : VCI --> MI Socket
  • Forwards pkt to socket M(pkt.VCI)
• Artifacts
  • Tunnel-aware sender and receiver
  • Slice process
  • spp-config-sp-vsvc-XXX.sh (slowpath) configuration scripts
  • Monitoring

Fastpath Implementation

• Requires mods to Parse and Header Format
• Uses generic Lookup
• Additional artifacts
  • spp-config-fp-vsvc-XXX.sh (fastpath) configuration scripts
  • Monitoring

Interesting Demo

• xxx