Patterns in Universal Plug

1
Patterns in Universal Plug Play

• Markus Alexander Wischy

2
Pick and verify

• Motivation
• Avoiding a central resource manager for
  allocating resources
• Solution
• Randomly choose a resource
• Verify that this resource is not in use
  (multicast/broadcast)
• Use the resource or choose another resource
• Known uses
• Used in Auto-IP (for IP adresses)

3
Lease and Locator

• Leases can provide a soft state
• Add robustness to changing environments
• Additional update messages provide more actuality
  to the soft state
• Adding Queries and complementary Announcement
  messages provide means to balance actuality and
  network traffic
• Lease messages can contain other information
  (e.g. location), avoiding futher messages or
  central components

4
Other concepts

• XML Descriptions
• Standardized DTD can provide Introspection
  functionality
• Multicast/Broadcast
• Avoiding a central component in the network
• Fails to scale to large networks

5
Discussion points

• The pick and verify schema of Auto-IP can be
  described as a pattern
• XML descriptions provide Introspection
  functionality
• Soft states are an important concept of leases
• Lease renew messages can contain additional
  information (e.g. location)
• Location information can be distributed by a
  distributed algorithm, avoiding a central
  component in the network