A Multiprotocol Framework for Adhoc Service Discovery

1
A Multi-protocol Framework for Ad-hoc Service
Discovery
MPAC 2006

• Carlos Flores, Gordon Blair, Paul Grace
• c.florescortes, gordon, gracep_at_comp.lancs.ac.uk
• 28th November 2006

2
Agenda

• Motivation
• Research Goal
• Ad-hoc Service Discovery Protocols Architecture
• Ad-hoc Service Discovery Framework
• Future Work
• Conclusions

3
Highly Heterogeneous Mobile Environments
Taxi (GSD) Taxi (SSD) Weather (ALLIA) Traffic
(GSD) Tourism (SLP-B)

• Middleware platforms should have the following
  requirements
• Discover services irrespectively of the
  discovery platform used.
• Discover services in diverse mobile scenarios
  and environmental conditions.
• Provide efficient mechanisms to interact with
  different SDPs simultaneously (i.e.
  configurability, dynamic re-configurability)
• Discover services featuring low performance
  overhead in terms of resource usage of the
  device, and network bandwidth consumption.

W E A T H E R
TRAFFIC
TOURISM
4
Research Goal

• Development of a configurable and dynamically
  reconfigurable multi-personality discovery
  middleware for operation in both nomadic and
  MANET style operation.
• Common Interaction Pattern
• Ad-hoc Service Discovery Protocols.
• A component framework approach for the
  development of a configurable and dynamically
  reconfigurable multi-personality discovery
  middleware.

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
5
Ad-Hoc SDPs Architecture

• Agents
• User Agent
• Performs service discovery on behalf of the
  clients.
• Service Agent
• Represents and advertise services.
• Directory Agent
• Collects service advertisements and matches
  incoming requests against collected service
  descriptions.
• Architecture
• Directory-based (Centralized)
• Directory-less (Distributed)

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
6
Ad-Hoc SDPs ArchitectureDirectory-based
Architecture Interaction Pattern
1.- DAs advertise its presence (multicast)
2.- SAs register their services (unicast)
3.- DAs manage service advertisement
4.- UAs request a service (unicast)
5.- DAs match requested service description
6.- DAs send service reply (unicast)
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
7
Ad-Hoc SDPs ArchitectureDirectory-less
Architecture, Interaction Pattern
1.- SAs advertise their services (multicast)
2.- DAs store service advertisements
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
8
Ad-Hoc SDPs ArchitectureAgents Tasks
TASK
Directory-based
Directory-less
Advertise its presence
x
Manages service advertisements
x
x
Service description matching
x
x
DA
Generates service replies
x
x
x
Multicast
Unicast
x
x
x
x
Advertise its services
SA
Multicast
x
Unicast
x
Send service requests
x
x
Listen service replies
x
x
UA
Local
x
x
Multicast
x
x
Unicast
x
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
9
Ad-hoc Service Discovery FrameworkComponent
Framework Architecture
(Confiurability)
Policy
Cache
Advertiser

• Manages policies.

• Stores local service descriptions in cache.
• Generates service advertisements.
• Manages protocol control messages.
• Stores service advertisements and protocol
  messages in cache.

• Manages cache entries.
• Add.
• Replace.
• Update.
• Remove.

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
10
Ad-hoc Service Discovery FrameworkComponent
Framework Architecture
Request
Reply
Network

• IP Unicast routing.
• IP Multicast routing.
• Bordercast routing
• Ad-hoc routing

• Sends service replies
• Notifies applications of received replies

• Generates service requests.
• Processes incoming requests (matching).
• Forwards service requests.

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
11
Ad-hoc Service Discovery FrameworkService Agent
Configuration
(Re-configurability)
Advertiser
Policy
Network
Cache
TASK
Directory-based
Directory-less
Advertise its services
x
x
SA
Multicast
x
Unicast
x
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
12
Ad-hoc Service Discovery FrameworkUser Agent
Configuration
(Re-configurability)
Policy
Network
Request
Cache
Reply
TASK
Directory-based
Directory-less
Send service requests
x
x
Listen service replies
x
x
UA
Local
x
x
x
x
Multicast
Unicast
x
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
13
Service Discovery FrameworkDirectory Agent
Configuration
TASK
Directory-based
Directory-less
Advertise its presence
x
Manages service advertisements
x
x
Service description matching
x
x
DA
Generates service replies
x
x
x
Multicast
Unicast
x
x
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
14
Ad-hoc Service Discovery FrameworkMulti-protocol
Support
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
15
Ad-hoc Service Discovery FrameworkImplementation

• PROTOCOLS
• Group Service Discovery (GSD)
• A novel group-based service discovery protocol
  for manets
• Dipanjan Chakraborty, Anupam Joshi, Yelena Yesha,
  Tim Finin
• University of Maryland, Baltimore County
• Scalable Service Discovery (SSD)
• Scalable service discovery for MANET
• Francoise Sailhan, Valérie Issarny
• INRIA-Rocquencourt, France
• Alliance Based Service Discovery (ALLIA)
• Allia Alliance-based service discovery for
  ad-hoc environments
• Olga Ratsimor, Dipanjan Chakraborty, Anupam
  Joshi, Timothy Finin
• Univeristy of Maryland, Baltimore County
• SLP-Based Service Discovery (SLP-B)
• SLP-based service management for dynamic ad-hoc
  networks
• Stefan Penz

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
16
Ad-hoc Service Discovery FrameworkImplementation
Policy
Once
Cache
Once
Advertisement
Individual
Request
Individual
Reply
Individual
Network
Once
Advertisement

• Stores local service descriptions in cache.
• Generates service advertisements.
• Manages protocol control messages.
• Stores service advertisements and protocol
  messages in cache.

• Heterogeneous service description languages
• Heterogeneous messages types and structure
• Directory presence advertisements
• Directory election advertisements (SSD)

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
17
Ad-hoc Service Discovery FrameworkImplementation
Policy
Once
Cache
Once
Advertisement
Individual
Request
Individual
Reply
Individual
Network
Once
Request

• Service description matching
• Heterogeneous service descriptions
• Matching algorithms
• GSD
• Services are matched based on service groups
• SSD
• Services are also matched against others
  directories summaries

• Generates service requests.
• Processes incoming requests (matching).
• Forwards service requests.

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
18
Ad-hoc Service Discovery FrameworkImplementation
Policy
Once
Cache
Once
Advertisement
Individual
Request
Individual
Reply
Individual
Network
Once
Reply

• Execution of additional process
• Hit-rate statistics of successful service
  requests
• Use of a reverse-route table to forward replies

• Sends service replies
• Notifies applications of received replies

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
19
Ad-hoc Service Discovery FrameworkEvaluation -
Configurability
SLPB-Advertiser
ALLIA-Advertiser
SSD-Advertiser
GSD-Advertiser
Policy
SLP-BRequest
Network
ALLIA-Request
SSD-Request
Cache
GSD-Request

• Simplified configuration
• Same component types
• Same connection bindings
• Same configuration
• algorithm

SLPB-Reply
ALLIA-Reply
SSD-Reply
GSD-Reply
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
20
Ad-hoc Service Discovery FrameworkEvaluation -
Configurability

• FRAMEWORK CONFIGURATION
• ltConfigurationgt
• ltFrameworkgtServiceDiscoverylt/Frameworkgt
• ltComponentsgt
• ltComponentgt
• ltComponentNamegtAdvertiserlt/ComponentNa
  megt
• ltConnectionsgt
• ltConnectiongt
• ltNamegtAdvertiser_Networklt/Name
  gt
• ltSinkgtNetworklt/Sinkgt
• ltInterfacegtNetwork.INetworklt/I
  nterfacegt
• lt/Connectiongt
• ltConnectiongt
• ltNamegtAdvertiser_Cachelt/Namegt
  
• ltSinkgtCachelt/Sinkgt
  
• ltInterfacegtCache.ICAchelt/Inter
  facegt

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
21
Ad-hoc Service Discovery FrameworkEvaluation -
Configurability

• AGENT CONFIGURATION
• ltConfigurationgt
• ltFrameworkgtServiceAgentlt/Frameworkgt
• ltComponentsgt
• ltComponentgt
• ltComponentNamegtAdvertiserlt/ComponentNa
  megt
• ltConnectionsgt
• ltConnectiongt
• ltNamegtAdvertiser_Networklt/Name
  gt
• ltSinkgtNetworklt/Sinkgt
• ltInterfacegtNetwork.INetworklt/I
  nterfacegt
• lt/Connectiongt
• ltConnectiongt
• ltNamegtAdvertiser_Cachelt/Namegt
  
• ltSinkgtCachelt/Sinkgt
  
• ltInterfacegtCache.ICAchelt/Inter
  facegt

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
22
Ad-hoc Service Discovery FrameworkEvaluation -
Configurability

• PROTOCOL CONFIGURATION
• ltConfigurationgt
• ltNamegtGSDlt/Namegt
• ltComponentsgt
• ltComponentgt
• ltComponentNamegtAdvertiserlt/ComponentNa
  megt
• ltComponentTypegtGSD.Advertiserlt/Compone
  ntTypegt
• lt/Componentgt
• ltComponentgt
• ltComponentNamegtRequestlt/ComponentNamegt
  
• ltComponentTypegtGSD.Requestlt/ComponentT
  ypegt
• lt/Componentgt
• ltComponentgt
• ltComponentNamegtCachelt/ComponentNamegt
• ltComponentTypegtCommons.Cachelt/Componen
  tTypegt

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
23
Ad-hoc Service Discovery FrameworkEvaluation
Re-configurability
Configuration A
SLP-B Protocol Description
DA
Protocol
UA Framework Description
SSD Protocol Description
SA
UA
SLP-B
X
GSD Protocol Description
SSD
X
X
SA Framework Description
GSD
X
ALLIA
GSD Protocol Description
Configuration B
DA
Protocol
UA
SA
X
SLP-B
X
Configurator.load(UA, SLP-B) Configurator.unload(S
A, GSD) Configurator.load(UA, ALLIA)
SSD
X
X
GSD
ALLIA
X

• Simple re-configuration algorithms
• Well known configuration pattern

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
24
Ad-hoc Service Discovery FrameworkEvaluation
Component re-use
SLPB-Advertiser
ALLIA-Advertiser
SSD-Advertiser
GSD-Advertiser
Policy
SLP-BRequest
Network
ALLIA-Request
SSD-Request
Cache
GSD-Request

• Simplifies development effort and time
• Reduces resource usage
• Enhances configurability

SLPB-Reply
ALLIA-Reply
SSD-Reply
GSD-Reply
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
25
Ad-hoc Service Discovery FrameworkEvaluation
Framework overhead
Framework
Side by side
ALLIA
SSD
GSD
SLP-B
SIZE(KB)
SIZE(KB)
66.96
X
70.46
X
64.26
X
89.26
X
129.16
137.42
X
X
172.56
201.68
X
X
X
209.76
290.94
X
X
X
X
Size of framework personalities
Framework
Side by side
Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
26
Future work

• Fine-grained architecture
• Service description heterogeneity
• Interaction heterogeneity (Set of message types)
• Directory maintenance

• SDP Interoperability
• Monitor component
• Consider service discovery protocols from
  different network styles e.g. fixed, sensor,
  overlay etc.

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
27
Conclusions

• Ad-hoc Service Discovery Protocols
• SSD, GSD, ALLIA, SLP-B
• Common functionality.
• Ad-hoc Service Discovery Framework
• Evaluation with the implementation of 4 existing
  ad-hoc service discovery protocols
• Benefits
• Common component architecture
• Component re-use
• Minimize resource usage for multiple concurrent
  protocols
• Simplify development
• Code re-use
• Future work
• Fine-grained architecture
• Evaluate our framework with discovery protocols
  from different network styles
• Development of a middleware to provide service
  discovery interoperability across different
  network styles

Research Goal Ad-hoc SDPs Architecture
Ad-hoc SD Framework
Future work Conclusions
28
?
Carlos Flores, Gordon Blair, Paul
Grace c.florescortes, gordon, gracep_at_comp.lancs.
ac.uk