Implementing Service Location Protocol Directed Study: Networking at the Application Layer Presented by: Lucas Stephenson To: Richard Yu, Anthony Whitehead For: SYSC 5906 Tuesday, September-04-12

Overview 1.Purpose 2.SLP OSS Options 3.OpenSLP Provisions 4.OpenSLP Test Setup Setup Issues Tests Results Results Screenshot 5.Conclusion 2

Implement and verify that SLP can Find suitable TCP/IP network endpoints Unknown/Unfamiliar networks Any network service (novel, non-standard, uncommon, not supported by DHCP) Provide rudimentary query support Ensure solutions are low cost Simple over the counter hardware Low development time Purpose 3

SLP OSS Options LiveTribe ( A network service management console, contains an SLP module Java based Implemented into a broader software project jSLP ( Java implementation of SLP OSGi version available 1 year since project activity/discussion OpenSLP ( C cross platform implementation Low activity, but some discussions Java version available, but at least 10 years old 4

OpenSLP Provisions Code libraries supporting all SLP messages A host service application (daemon) Enables SA and DA functionality Required for DA and scope discovery Not required for basic UA usage (without scopes) A tool that allows interaction with the local daemon to send network messages 5

OpenSLP Test Setup Setup Consumer grade a/b/g/n wireless router and wired router Two Windows clients Client machine A: Windows XP, wired network connection only Client machine B: Windows 7, wired (802.11n) and wireless OpenSLP daemon started, default configuration (SA) 6

OpenSLP Test Setup Issues Initially used version 1 (latest officially stable release) Required compilation, requiring some minimal modifications Had issues, (no responses from server, despite registered services) Tried version 2, windows binaries pre-compiled Issues remained Seemed services weren’t being registered Created a simple C console implementation to register services The application worked! Discovered it stopped working once application window was closed Local PID monitoring! If a local application registers a service, the service is deregistered if the application closes Makes local registration using the command line useless! 7

OpenSLP Tests SLP allows services to be found using service types and service types with query-able attributes. Tests of each both types of request were performed The following services were registered on machine “A” service:io:diop://hostname.t1.com:1337 (- xChannels=5),(-xMuteable=true) service:io:diop://hostname.t2.com:1338 (- xChannels=7),(-xMuteable=false) Queries were performed using both the OpenSLP slptool and a C application using the OpenSLP Library, using the FindSrvs method. 8

OpenSLP Results The services were correctly found from machine “B” as well as from machine “A” by querying for the abstract type or abstract and concrete types: “ service:io ” or “ service:io:diop ” Varying LDAP queries on the 2 specified attributes also functioned, (see next slide) 9

Finding Services 10

Conclusion SLP protocol can locate service endpoints on an TCP/IP network. Single requirement: agents representing services must be accessible via multicast or broadcast. Additional platforms: due to time and unavailability of up to date code were not able to be verified. Query functionality provides a powerful means to locate and filter specific endpoints for compatible capabilities. However: No interaction with the endpoints are inherent and the endpoint doesn’t necessarily exist. 11

Thanks 12