Access Grid Workshop – APAC ‘05 Network Services Susanne Lefvert University of Chicago

Access Grid Workshop – APAC ‘05 Outline Introduction Limitations of Current Architecture Enhanced Architecture Network Services Example: Debug Service Exercises

Access Grid Workshop – APAC ‘05 Introduction Network Enable users to seamlessly participate in AG meetings. Middleware Stream processing

Access Grid Workshop – APAC ‘05 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

Access Grid Workshop – APAC ‘05 Class Diagram VenueClient AGNodeService AGServiceManager AGService AGServiceManager

Access Grid Workshop – APAC ‘05 Capability Role –CONSUMER –PRODUCER Type –AUDIO –VIDEO –TEXT Not Sufficient

Access Grid Workshop – APAC ‘05 Sequence Diagram Mismatch can not be resolved

Access Grid Workshop – APAC ‘05 Limitations of Current Architecture 1.Service capability description limited 2.User preferences do not exist 3.No resolution to capability mismatch

Access Grid Workshop – APAC ‘05 Enhanced Capabilities Schema including: 1.Service capability Device (sample rate, sample size, sample format…) Encoding (name, quality, bit rate, size…) RTP (payload type, profile…) 2.Node capability Available bandwidth, multicast, firewall… 3.User preferences Preferred quality, bandwidth…

Access Grid Workshop – APAC ‘05 VenueClient AGNodeService AGServiceManager AGService AGServiceManager Capability Service Capability Node Capability User Preferences

Access Grid Workshop – APAC ‘05 Sequence Diagram

Access Grid Workshop – APAC ‘05 Network Service y = Transform(x) xy xy

Access Grid Workshop – APAC ‘05 Matcher Venue Stream Capabilities Node Capabilities Mismatch 1. Network Service Node Capabilities Stream Capabilities Match 2.

Access Grid Workshop – APAC ‘05 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

Access Grid Workshop – APAC ‘05 Example: Video Selector GOAL: Reduce bandwidth EXAMPLE: Connect from home

Access Grid Workshop – APAC ‘05 Multicas t Video Selector Example: Video Selector

Access Grid Workshop – APAC ‘05 Example: Transcoder GOAL: Enable more devices EXAMPLE: H.323 client

Access Grid Workshop – APAC ‘05 Multicas t Audio Transcoder Multicas t Linear16pcmu Example: Transcoder

Access Grid Workshop – APAC ‘05 Implementation Details 1.Add new capabilities (ServiceCapability) to your node services. 2.Create a network service matching the new capabilities of the node services. 3.Connect the network service to the venue 4.Connect your node services to the venue

Access Grid Workshop – APAC ‘05 Network Service Base Class Initiates the AG environment Hides SOAP details Includes logging Communicates with venues Includes the Transform() method

Access Grid Workshop – APAC ‘05 Service Capabilities Describe input and output Same as node service capabilities Used during capability negotiation and network service matching

Access Grid Workshop – APAC ‘05 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()

Access Grid Workshop – APAC ‘05 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(" ", 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

Access Grid Workshop – APAC ‘05 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]

Access Grid Workshop – APAC ‘05 Exercises 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

Access Grid Workshop – APAC ‘05 Exercises 1: Video Selector 1.Install the modified node services with new capabilities. 2.Enter the venue the video selector is connected to 3.Switch between video selection on and off

Access Grid Workshop – APAC ‘05 Exercises 2: Debug Service 1.Install the two modified node services with new service capabilities 2.Modify the Debug Network Service 3.Connect the network service to a venue and enter with the two node services to trigger matching.

Access Grid Workshop – APAC ‘05 Exercises 3: SOAP Interface 1.Add a SOAP interface to the debug service 2.Create a client that can communicate remotely with the debug network service SOAP interface.