1. SILO: A novel framework for flexible protocol composition
The SILO project is
funded by the
National Science Foundation
FIND Grant
SILO: A novel framework for flexible protocol composition
Ilia Baldine,
Renaissance Computing Institute
George Rouskas, Rudra Dutta,
Anjing Wang, Mohan Iyer
North Carolina State University,
Dan Stevenson
RTI

3. Motivation Observations of the current state Looking forward
Balkanization of protocols (VoIP, sensor nets, wireless, high-speed)
Proliferation of half-layer solutions (IPSec, MPLS etc)
Ossification of protocol research (e.g. growing number of TCP variants)
Lack of explicit cross-layer interactions
Inability to separate salient features of protocols
Looking forward
Provide ways for smooth evolution of protocols for new transport technologies, control algorithms
- Clearer link to ‘why’ we did what we did. Why composable, why separate control and data paths, this is ‘meta-design’

4. Musings
Layering is important, however rigid layer boundaries are limiting
Design for change: create a meta-design that can accommodate future changes
Architecture must constrain – otherwise you get proliferation of functions at various places
But must not constrain wrong thing and stifle innovation, ossify, etc.
Job of architecture – constrain (channel) the mechanisms used for different players to bring their various pieces and use them

5. Traditional and SILO network stacks
Transport
Network
Data Link
Physical
Physical Channels
App
Cross-
Service
Tuning
silo &
service
mgmt
strategies,
hints
Composability
Constraints
m11
m13
m21
m31
m42
m43
m62
m61
Layering is good
Application writer must be able to clearly communicate their needs (abstractly)
Data transformation mechanisms should be separated from optimization

6. SILO Features Emphasis on re-usability, not miniaturization
Automated construction of silos via ontology
Explicit cross-layer control and interactions
Separation of mechanisms from policies
Do not require specific OS architecture – just a convention for implementation (template or pattern)

7. SILO architecture high-level view

8. Service/Method Paradigm

9. The SILO hourglass What is the convergence point? Service API
Ontology schema (a language to describe network services)

10. SILO Ontology
Encodes knowledge on relations between services and methods
Encodes service types and functions to enable ‘fuzzy’ inference
Written using Protégé in RDF
Work in progress

11. SILO Ontology tools

12. SILO as a research tool
SILO is deployed with ontology and existing set of services
Researcher brings
Custom services
Tuning algorithms
Ontology updates
Can connect to measurement functions to provide a cross-layer protocol experimentation tool
Allows experimentation with various layering approaches exploring the optimization space
Allows protocol experimentation

13. Wireless example: adaptive transport
Goal: design a set of services and cross-layer tuning algorithm to maximize goodput across a wireless network
Adaptive FEC service
Adaptive MTU service
Adaptive window management service
Tuning algorithm to manage the knobs

14. Optical example: impairment-aware routing
Goal: design an optical-impairment-aware routing protocol that maximizes network utilization
Distributed impairment measurement capabilities (e.g. PMD)
Routing service capable of using the information
SILO makes it trivially simple to have multiple routing protocols in the same host and different applications using different routing protocols

15. Silo proof-of-concept
User-space open framework
C++ and Python
Methods are DLLs with a well-defined interface
Silo construction agent uses ontology to create an XML “recipe” for a silo
Silo Management Agent
Loads and executes the code for silos based on packet events and timers
Maintains silo state
Silo Tuning Agent is a container for tuning algorithms/strategies associated with services
Universe of Services contains the ontology and dynamically loadable code implementing methods

16. Available APIs Application API Service API
Socket like for managing data transfers
Ability to specify constraints on silo construction imposed by the application writer
Service API
Well-defined set of functions for managing service interfaces (upper, lower, tuning knobs and gauges)
SBuf (mbuf or skbuf like) state
Service state

17. SILO Prototype

18. Demo setup

19. DEMO

20. Future steps Joint projects Silo similarity/synchronization
Converged Services Platform
Optical IMF for GENI
Silo similarity/synchronization
Construction of siloplexes
Software-defined optics
Network Virtualization
Consistency
Stability
New services
New transports
New addressing schemes
New routing implementations ….
Used in a class. Developing VCAT/LCAS