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Implementing Universal Plug And Play In Smart Objects And Intelligent Appliances Bengt Christensson CTO Axis Communications . Session Overview. Technology trends Challenges and requirements Solutions to date and the Universal Plug and Play Way Implementation Demo Call to action.
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Implementing Universal Plug And Play In Smart Objects And Intelligent AppliancesBengt Christensson CTOAxis Communications
Session Overview • Technology trends • Challenges and requirements • Solutions to date and the Universal Plug and Play Way • Implementation • Demo • Call to action
Technology Trends • Focus shifting from connectivity to services • More devices/services will be networked • Use your time efficiently • Ubiquitous communications • Anywhere, anything and intuitive, too • Useful bandwidth available • Home networking
Devices, PCs And Services Interconnect Services Technologies converge, devices don’t
Challenges • Simplicity • Robustness - “always on” • Scalability- ad hoc/configured • Interoperability, manageability, security • Lightweight cost-effective technology • Building networking applications • Wide range of different devices and services...
Protocol Requirements • “Automatic networking” • Address assignment, naming, discovery, and service identification • Scalability • Work in serverless environments and leverage directory services, if available • Dynamic ad hoc environments • Flexibility • Support device and service individuality • Open standards-based • Internet RFCs, public source
Solutions To Date • Ad hoc (serverless, peer-to-peer) • Manual IP address assignment, ARP • No intuitive naming • SLP, SMB, Salutation, “flood-ping” • Configured (server-based) • DHCP, BOOTP, RARP • DNS, WINS • Directory (LDAP, NDS, SLP, Salutation)
The Universal Plug And Play Way • Works in both ad hoc and configured environments • XML and XSL style sheets in the device define service and interaction
Applications ADSI Simple Service Discovery XML LDAP Universal Plug and Play provider WINSOCK TCP/IP stack NDIS Client Components NIC
Simple Discovery (~4k) HTTP (~20k) XML, XSL schema TCP/IP stack (~40k) AutoNet DHCP Smart Object Components Device functions Physical media
1. DHCP broadcast 2. Assign AutoNet address 3. DNS name multicast 4. Announce service 5. Discover service 7. Response to discover 8. GetXMLschema 9. XML schema Universal Plug And Play In Action - Ad Hoc (Timeout) (Timeout - wait for requests)
1. DHCP broadcast 2. Address from DHCP server 3. Name unicast to DNS server 4. Announce service to listener 5. Listener Get_HTTP XML 8. LDAP query directory Universal Plug And Play In Action - Configured Server 6. Directory updated by listener 7. Device-specific negotiation
Packet Examples Announce • HTTP packet data example ANNOUNCE * HTTP/1.1 HOST: * Location: http://170.1.128.135/description.xml Object-Class: printer • Multicast UDP packet
Packet ExamplesDiscover and response • Discover DISCOVER (objectClass=printer) HTTP/1.1 HOST: 172.*.*.* Request-ID: 54 • Response to discover HTTP/1.1 302 Found Request-ID: 54 Location: http://172.1.128.135/description.xml Object-Class: printer
Axis Camera Example • Implementation • Network-attached surveillance camera • Self-contained with TCP/IP and HTTP support • UPnP with XML/XSL description • Approx. 40 k bytes for UPnP needed
XML Schema Axis Camera • Key elements • Name spaces definitions • Device description and functionality • Support and purchasing information • References to XSL style sheets for UI • Refer to white paper for sample code, XML schema and XSL style sheets http://www.axis.com/products/documentation/ UpnP.doc
‘Device Browser’ Example • Client runs Device Browser application, based on Internet Explorer 5.0 • Discover device • Fetch description.xml from device • Parse XML data to extract information • Present device in view • User selects device • Present UI links referred by description.xml • User selects UI • Fetch and view the UI (style sheet)
PC Ethernet Camera Printer CD tower Live Demo • Showing UPnP • Device discovery - ‘Device Browser’ • Device interaction - XSL Style Sheets
Documentation • Simple Service Discovery Protocol • http://search.ietf.org/internet-drafts/draft-cai-ssdp-v1-00.txt • Automatic Private IP Addressing • http://www.ietf.org/internet-drafts/draft-ietf-dhc-ipv4-autoconfig-03.txt • Multicast DNS (name resolution) • http://search.ietf.org/internet-drafts/draft-manning-multicast-dns-01.txt
Documentation • White paper • http://www.axis.com/products/documentation/UpnP.doc • Home Networking & Universal Plug and Play web sites • http://www.microsoft.com/homenet • http://www.upnp.org
Call to Action • UPnP is work in progress! • Review your business opportunities with respect to UPnP • Get to understand the principles and general requirements • Study released documentation • Keep an eye on www.upnp.org • More great news to come!