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

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’

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

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

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)

SILO architecture high-level view

Service/Method Paradigm

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

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

SILO Ontology tools

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

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

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

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

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

SILO Prototype

Demo setup

DEMO

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