Network Services

1. Network Services Susanne Lefvert lefvert@mcs.anl.gov University of Chicago

2. Outline • Introduction • Limitations of Current Architecture • Enhanced Architecture • Network Services • Example: Debug Service • Exercises

3. Introduction • Enable users to seamlessly participate in AG meetings. • Middleware • Stream processing Network

4. Heterogeneous Environment • Devices • VIC, RAT, Quicktime, Realplayer, H.323 clients… • Formats • Different encodings, sample rate … • Network • Available multicast, bandwidth … • Preferences • Surgery: Want high resolution video • Presentation: Want lower resolution video

5. Class Diagram VenueClient AGNodeService AGServiceManager AGServiceManager AGService AGService AGService AGService

6. Capability • Role • CONSUMER • PRODUCER • Type • AUDIO • VIDEO • TEXT Not Sufficient

7. Sequence Diagram Mismatch can not be resolved

8. Service capability description limited User preferences do not exist No resolution to capability mismatch Limitations of Current Architecture

9. Schema including: Service capability Device (sample rate, sample size, sample format…) Encoding (name, quality, bit rate, size…) RTP (payload type, profile…) Node capability Available bandwidth, multicast, firewall… User preferences Preferred quality, bandwidth… Enhanced Capabilities

10. VenueClient User Preferences AGNodeService Node Capability AGServiceManager AGServiceManager AGService AGService AGService AGService Capability Capability Service Capability

11. Sequence Diagram

12. Network Service y = Transform(x) x y x y

13. Matcher 1. Venue Stream Capabilities Node Capabilities Mismatch 2. Stream Capabilities Node Capabilities Network Service Match Match

14. Network Service • Registers with a venue or a venue server • Includes input and output capabilities • Provides a Transform() method • Has an interface for remote configuration • Emits heartbeats

15. Example: Video Selector GOAL: Reduce bandwidth EXAMPLE: Connect from home

16. Example: Video Selector Multicast Multicast Video Selector

17. Example: Transcoder GOAL: Enable more devices EXAMPLE: H.323 client

18. Example: Transcoder Linear16 pcmu Multicast Audio Transcoder Multicast

19. Implementation Details • Add new capabilities (ServiceCapability) to your node services. • Create a network service matching the new capabilities of the node services. • Connect the network service to the venue • Connect your node services to the venue

20. Network Service Base Class • Initiates the AG environment • Hides SOAP details • Includes logging • Communicates with venues • Includes the Transform() method

21. Service Capabilities • Describe input and output • Same as node service capabilities • Used during capability negotiation and network service matching

22. Example: Video Selector class SelectorNetworkService(AGNetworkService): def __init__(self, name): AGNetworkService.__init__(self, name, 'Selector', '1.0') # Create capabilities inconfig = {"Encoding":"H261"} inCap = ServiceCapability(name, 'consumer', 'video', inconfig) outconfig = {"Encoding":"H261", "StreamSelection":"On"} outCap = ServiceCapability(name, 'producer', 'video', outconfig) self.inCapabilities = [inCap.ToXML()] self.outCapabilities = [outCap.ToXML()] # Manage processes self.processManager = ProcessManager() # Start the soap interface self.Start(self) def StopTransform(self, streamList): # Stop video selector self.processManager.TerminateAllProcesses()

23. Example: Video Selector def Transform(self, streamList): # Start video selector newStreams = [] for s in streamList: cap = s.capability cap.xml = self.outCapabilities[0] # Create new stream description location = MulticastNetworkLocation("224.2.2.2", 8000) ns = StreamDescription("Video Selector Stream", location, cap) newStreams.append(ns) # Create process arguments fromaddr = s.location.host fromport = s.location.port toaddr = ns.location.host toport = ns.location.port executable = os.path.join(os.getcwd(), "Selector.py") options = [executable, fromaddr, fromport, toaddr, toport, 1] # Start process self.processManager.StartProcess(sys.executable, options) return newStreams

24. Example: Video Selector Consumer Service def __SetCapabilities(self): oldCap1 = Capability( Capability.CONSUMER, "video" ) # Create new capabilities to include in old capability format val = "Off" for c in self.configuration: if c.name == "video selection": val = c.value config = {"StreamSelection": val, "Encoding":"H261"} nsc1 = ServiceCapability('Video Consumer Selector', oldCap1.role, oldCap1.type, config) oldCap1.xml = nsc1.ToXML() self.capabilities = [oldCap1]

25. Exercises http://www.mcs.anl.gov/fl/research/accessgrid/documentation/tutorial/AGTk_2.4 Exercise 6 – Network Services: • Testing the video selector service • Running a debug network service • Creating a custom SOAP interface for configuration • Creating a client for connecting to the custom SOAP interface

26. Exercises 1: Video Selector • Install the modified node services with new capabilities. • Enter the venue the video selector is connected to • Switch between video selection on and off

27. Exercises 2: Debug Service • Install the two modified node serviceswith new service capabilities • Modify the Debug Network Service • Connect the network service to a venue and enter with the two node services to trigger matching.

28. Exercises 3: SOAP Interface • Add a SOAP interface to the debug service • Create a client that can communicate remotely with the debug network service SOAP interface.