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Research Challenges for Military Networking
Ken Young
(973) 829-4928
September 6, 2002
Cornell Workshop 6 Sept 2002– 2
Talk Outline
Background on military networking challenges– ARL CTA program– DARPA AJCN program– CECOM MOSAIC ATD
Networking technologies– Node and domain autoconfiguration– Routing– Reliable transport– Other challenges
Integration challenges Transition challenges Conclusions
Cornell Workshop 6 Sept 2002– 3
Current Battlefield Networks - Tactical Internet
Division TOC
Battalion TOC
Brigade TOC
Brigade TOC
Brigade TOC
Battalion TOC
Battalion TOC
Upper Echelon
SINCGARS (Single Channel Ground and Airborne System)
EPLRS (Enhanced Position Location Reporting System)
NTDR
MSE
Cornell Workshop 6 Sept 2002– 4
Future Battlefield Networking Concept
OTM Enclave
OTM Enclave
Sensor Nets
SustainingBase
Cornell Workshop 6 Sept 2002– 5
FCS Networking Implications
Mobile ad hoc networks must smoothly blend heterogeneous physical layers
Self-organizing and self-managing network operations Networking that accommodates directional antennas Network sessions must be maintained while on-the-move Network survivability with graceful degradation High throughput for collaborative C4ISR to support network-centric
operations QoS for real-time traffic with dynamic network topologies Indirect routing and dynamic load balancing Mitigation of MAC/routing/transport layer vulnerabilities Topology control and predictive routing for mobile line-of-sight
backbones
Cornell Workshop 6 Sept 2002– 6
Survivable Wireless Mobile Networks
Objective: Dynamically self-configuring wireless network technologies that enables secure, scaleable, energy-efficient, and reliable communications
Research challenges– Scalability to thousands of nodes
– Highly mobile nodes and infrastructure
– Severe bandwidth and energy constraints
– Decentralized networking and dynamic reconfiguration
– Accommodation of high bit-error-rate, wireless networks
– Seamless interoperability
Scientific barriers– Understanding of trade-offs under bandwidth, energy, processing
capability, bit-error-rate, latency, and mobility constraints
– Understanding of interactions between cross-layer algorithms
– Limited modeling capability for scaling distributed algorithms
Cornell Workshop 6 Sept 2002– 7
Config Server
ACM
Interface
Config Database
NodeNetwork GUI
Local GUI
Node/Network Autoconfiguration
Preconfigurednode capabilities
YAP low-bandwidth configuration reports
MySQLDCDP distributes new configuration
DRCP configures subnet interfaces
DCDP: Dynamic Configuration Distribution ProtocolDRCP: Dynamic and Rapid Configuration Protocol
YAP: Configuration database maintenance and access protocol
ACM: Adaptive Configuration Manager
N-GUI: Display of network topology and configurationL-GUI: Display of local node capabilities and configuration
BB
Cornell Workshop 6 Sept 2002– 8
Node/Network Autoconfiguration Performance
0
2
4
6
8
10
12
14
16
18
100 200 300 400 500 600 700 800 900 1000
Number of nodes
Co
nfi
gu
rati
on
Tim
e (s
eco
nd
s) dense
sparse
0
500
1000
1500
2000
2500
3000
3500
100 200 300 400 500 600 700 800 900
Number of nodes
Ban
dw
idth
(b
yte
s/s
eco
nd
)
Subnet overhead (refresh=10s)
Subnet overhead (refresh=30s)
Network overhead (refresh=10s)
Network overhead (refresh=30s)
AutoconfigurationOverhead
AutoconfigurationTime
Cornell Workshop 6 Sept 2002– 9
Domain Autoconfiguration
Objective: Autoconfigured domains for scalable, survivable and efficient routing, configuration, security and QoS in dynamic networks
XXXXX
Flat terrain
Mountainous terrain
Stable links
Unstable links
Research issues– Dynamically selecting border nodes – Aggregating domain information– Algorithms to dynamically decide domain membership based on node mobility, roles,... – Scalable and robust protocols to create and maintain domains in dynamic networks– Isolating and resolving faults and intrusions using dynamic domain reconfiguration
Approach– Hierarchical topological domains built from individual interfaces– Independent domains for each function
Cornell Workshop 6 Sept 2002– 10
MANET Routing ExamplesMANET Routing Examples
MANET Routing Hierarchy
JTRS WNW Subnet
Dismount Radios
Backbone NetworkConventional Routing
MANET Routing
MANET Routing
Gateway/Border Router Nodes
• AODV• DSR• ZRP
• OLSR• TBRPF• LANMAR
• FSR• WARP• DRD
• TORA• FSLS• ....
Cornell Workshop 6 Sept 2002– 11
Dynamic Border Router
XXXXX
Flat terrain
Mountainous terrain
Stable links
Unstable links
Enhanced autoconfiguration technology to create and maintain domains
- DBR automatically selected if node has interfaces in multiple domains
- Demonstration on small testbed (AODV/RIP & AODV/AODV)
- Transition to CECOM MOSAIC ATD
Automatically selected by ACM- Developing algorithms to dynamically
decide domain membership based on node mobility, roles, link stability...
Cornell Workshop 6 Sept 2002– 12
Heterogeneous Domain Routing Objective: Develop scalable and efficient routing protocols in
heterogeneous mobile wireless networks
Highly dynamic domain
Link failurenotification
Routing modules
Reverse routenotification
Domain instances
Probabilisticbroadcast
Domain instances
Static, sparse domain
Inter-domainrouting
Domain specific routing
Approach– Configure/reconfigure the network into more homogeneous routing domains– Design routing modules specific to each domain for intra-domain routing
Challenges– Characterizing performance of routing strategies in dynamic and Byzantine environments– Interactions of routing protocols at the border nodes– Developing inter-domain routing protocols for routing among border nodes
Cornell Workshop 6 Sept 2002– 13
NEs
Bandwidth Broker
Network Nodes (Routers)
Other BBs
Applicationsvia
Service Manager(SM)
Admission Control& Resource
Manager
ResourceDatabaseResourceDatabase
ResourceDatabase
Admission Control& Resource
Manager
Admission Control& Resource
Manager
Bandwidth Broker Functional Components
IP-level topology• Config. Database dynamically updates
Per Class Resource Information• Provisioned and available link capacity
Call Status Information
QoS Resource Management within domain• Database initialization and update• QoS Resource configuration in nodes
Admission Control into the domain• Based on network state, policy & requests• Also call/session events across domains
PolicyDatabase
PolicyDatabase
PolicyDatabase
Domain wide QoS policy info• DiffServ functions in nodes
ConfigurationDatabase
viaYAP Server
Reliable UDP avoids TCP congestion control problems in wireless environmentReliable UDP communication• Avoids TCP congestion control problems
Cornell Workshop 6 Sept 2002– 14
Some Comparative Performance Test Results
PLR Util PLR Util PLR Util PLR Util
AF4 - TCP 67% 0.9% 0.66% 70% 0.73% 80%
AF3 - VoIP 0.64% 80% 30% 56% 0.68% 80% 1.01% 80%
AF2 - Video 0% ~90% 30% ~50% 0.56% ~90% 0.43% ~90%
AF1 - UDP 128-byte 0% 100% 30% 70% 0.67% 100% 12% 90%
BE - UDP 1024-byte 0.15% 96% 33% 65% 87% 65% 86% 70%
Service Class
Single Class
No DiffServ
DiffServ/BB
107 VoIP calls
WRR Priority
Cornell Workshop 6 Sept 2002– 15
Reliable Transport Objective: Alternative transport protocols that increase end-to-end
performance, survivability, and reliability of FCS applications Approach
– SCTP (RFC 2960) for FCS environment Partial delivery for differentiated QoS of multiple
prioritized streams Multi-homing and cross-stream data bundling to
provide load balancing and path selection Denial-of-service-resistant connection establishment
– Analyze empirically using SCTP reference implementations
– Evaluate performance tradeoffs under different mobility conditions
– Define visionary progress of SCTP for FCS
Research Issues– Performance during failover/changeover– Performance/bandwidth impact of avoiding abort/restart transport connections that support longer term applications– Optimal flow control for providing different QoS for application streams using same transport connection
Application
SCTP
IP
...
...
port
IP addresses
Link
Physical
132 (IANA)
Cornell Workshop 6 Sept 2002– 16
• Explore new transport layer alternatives for survivable wireless mobile networks
• Capitalize on opportunity to influence SCTP standard
• Split Fast Retransmit Changeover-Aware Congestion Control (SFR CACC) algorithm submitted as IETF Internet Draft
• Exploit transport layer multi-homing for uninterrupted end-to-end communication
• Significantly enhances transport layer’s ability to support persistent on-the-move sessions for FCS networks
Improved Transport Layer Congestion Control
Cornell Workshop 6 Sept 2002– 17
Other Networking Research Challenges Data Link Layer
– Energy-efficient topology control and MAC– Self-organizing subnets
Quality of Service– Estimating bandwidth and delay on individual links– Allocating bandwidth and delay to meet end to end objectives– QoS coordination across layers (physical to application)
Multicast– With mobility, QoS, etc.– Reliable multicast
Security– Distributed dynamic trust establishment and key management– Efficient, robust message authentication– Intrusion detection and mitigation– Vulnerability assessment
Network Management– Fault detection and localization– Self-healing– ....
Cornell Workshop 6 Sept 2002– 18
Integration Example – MOSAIC AMPS
Function SubfunctionProtocol/Entity Source Code
Subnetwork DRCP Telcordia C++Network DCDP Telcordia C++Management ACM Telcordia Java
SIP Telcordia JavaDDNS Linux CDMA Telcordia CMangler Telcordia Java
Unicast RIP Zebra CAd hoc unicast AODV Mad-hoc/NIST CMulticast HLIM Telcordia CAd hoc multicast MAODV U. Maryland CBorder router DBR Telcordia C
Reliability Transport SCTP Siemens CReporting YAP Telcordia JavaLocal L-GUI Telcordia JavaNetwork N-GUI Telcordia JavaAuthentication, key exchange IKE freeswan CIntegrity, privacy IPSec freeswan C802.11 SQC Telcordia CIP DiffServ Telcordia CManagement BB Telcordia Java
Security
Location
Continuous connectivity
QoS
Configuration
Mobility Management
Visualization
Routing
Cornell Workshop 6 Sept 2002– 19
Transition Example - JTRS SCA 2.0 View
Core Framework (CF)Commercial Off-the-Shelf
(COTS)
Applications
OE
Red (Non-Secure) Hardware Bus
CFServices &
Applications
CORBA ORB &Services
(Middleware)
Network Stacks & Serial Interface Services
Board Support Package (Bus Layer)
POSIX Operating System
Black (Secure) Hardware Bus
CFServices &
Applications
CORBA ORB &Services
(Middleware)
Network Stacks & Serial Interface Services
Board Support Package (Bus Layer)
POSIX Operating System
Core Framework IDL (“Logical Software Bus” via CORBA)
Non-CORBAModem
ApplicationsNon-CORBAModem API
Non-CORBASecurity
Applications
Non-CORBAHost
ApplicationsNon-CORBASecurity APIRF
ModemApplications
Link, NetworkApplications
SecurityApplications
ModemAdapter
SecurityAdapter
SecurityAdapter
HostAdapter
HostApplications
Modem API Link, Network API Link, Network API
Non-CORBAHost API
Link, NetworkApplications
APISecurity
AMPSAMPSAMPS
Cornell Workshop 6 Sept 2002– 21
Conclusions
Networking challenges at multiple layers; interactions between layers key in wireless mobile networks– Data link– Network– Transport
What’s most important? Current FCS LSI opinion is that highest risk areas are:– Mobility– Heterogeneous QoS– Scalability
Also many interesting research issues in the “seams”– Integration– Transition