Common Characteristics of Discovery Mechanisms

Common Characteristics:

• Discovery Service (SLP is good)
• Service Subtyping
• Service Appearance and Disappearance: Highly dynamic updates in both service arrival and demise (except crash of service)
• Service Browsing
• Catalogs of Available services: UPnP is inherently P2P, hence doesn't require catalogs to be published, Jini publishes catalogs for clients, whereas SLP has both options.
• Eventing
• Garbage Collection: Leases are a popular garbage collection mechanism.

Overviews:

SLP:

• User Agents(UA) search for needed services on behalf of clients.
• Language Neutral.
• (OpenSLP)

UPnP:

• Device and service descriptions are coded in XML.
• UPnP does not support service directories - communication between devices and clients is always direct.
• UPnP is aimed at smaller environments.
• (UPnP SDK)

Bluetooth:

• Blutooth devices maintains sets of service records, each of which describes an available service.
• Is lightweight , because it is meant for Personal Area Networks