1. DTNs and GENI Measurement
Will Leland
First GENI Measurement Workshop
Madison, WI

2. Implications for GENI Measurement
Looking at GENI measurement requirements and system with some specific research areas in mind
Disruption Tolerant Networking (DTN)
Content-Based Access (CBA)
Wider network science context
Focus on
What support do these areas need from the GENI measurement infrastructure?
What benefits might they bring to realizing that infrastructure?

3. DTN Key Concepts Exchange “bundles”, which have explicit lifetimes
Network not necessarily ever connected
No need for end-to-end connected path
Network opportunistically routes a bundle “toward” its destinations
Network holds a bundle till its lifetime expires
Bundles have metadata
Metadata may be more widely distributed than the data
Data and metadata may have different access control
Destinations can be described, rather than addressed
Late binding of destinations
Deliver to destinations that match description at any time during the bundle’s lifetime

4. GENI as a Disrupted Network
GENI can be a powerful tool for studying networks with challenged components
GENI slices can contain challenged components (e.g., sensors, MANET nodes, etc)
Location, time synch, real-time access may be unavailable
Federation implies subnets can join, leave, rejoin
The measurement infrastructure itself may be disconnected
A (logically) central repository for measurements may be infeasible
A researcher’s access may be intermittent
Federated components may have constraints on what can be measured or what measurements can be shared
Technology, policy, contingency, …

5. Implications for Measurement Architecture
Preserve characterizations of limitations in time & location information
Allow researchers to specify what characterizations are needed and what limitations in characterization are acceptable for components of a slice
E.g., social role may matter more than physical location
Extend definitions to cover challenged networks
For example, a “link” may be a data mule
How should one usefully characterize a grad student with a backpack full of USB drives?
Address disparate levels of what is being delivered
How does the experimenter know a bundle has been delivered? What is the definition of successful delivery?
Exploit DTN technologies for collection, distribution, and retrieval of measurement data

6. GENI Measurement Requirements
Some relevant requirements
GENI System Overview GENI-SE-SY-SO-02.0.doc
Sec 10.1 GENI instrumentation and measurement system (GIMS)
Ubiquitous deployment
No impact
High availability
Central repository
GENI System Requirements Document GENI-SE-SY-RQ-01.9, sec 7
7.1-1: component measurements
7.1-3: link measurements "optical, wired and wireless links”
7.1-7: real-time access to measurements
7.1-8: component locations
7.1-9: time services: "a common timeframe for all measurements, synchronized to within TBD microseconds across the system"