1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (1/6)Implementation Issues (1/6)

Usage of TSAP IDsUsage of TSAP IDs Reliable or UnreliableReliable or Unreliable Well known or dynamicWell known or dynamic

Audio/RTPAudio/RTP UnreliableUnreliable DynamicDynamic

Audio/RTCPAudio/RTCP UnreliableUnreliable DynamicDynamic

Video/RTPVideo/RTP UnreliableUnreliable DynamicDynamic

Video/RTCPVideo/RTCP UnreliableUnreliable DynamicDynamic

Call SignallingCall Signalling ReliableReliable Well known or dynamicWell known or dynamic

H.245H.245 ReliableReliable DynamicDynamic

Data(T.120)Data(T.120) ReliableReliable Well known or dynamicWell known or dynamic

RASRAS UnreliableUnreliable Well known or dynamicWell known or dynamic

TSAP Ids used by H.225.0 per point-to-point unicast callTSAP Ids used by H.225.0 per point-to-point unicast call

1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (2/6)Implementation Issues (2/6)

Unreliable deliveryUnreliable deliveryapplicationapplication

Call Signalling and Call Signalling and H.245 channelH.245 channel

UDPUDP TCPTCP

IPIP

Link LayerLink Layer

Physical LayerPhysical Layer

1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (3/6)Implementation Issues (3/6)

Discovery the GatekeeperDiscovery the Gatekeeper Gatekeeper UDP Discovery Multicast Address 224.0.1.41Gatekeeper UDP Discovery Multicast Address 224.0.1.41 Gatekeeper UDP DiscoveryGatekeeper UDP Discovery 1718 1718 Gatekeeper Registration and Status PortGatekeeper Registration and Status Port 1719 1719

Endpoint to Endpoint CommunicationEndpoint to Endpoint Communication Endpoint TCP Call Signalling PortEndpoint TCP Call Signalling Port 1720 1720

While it is permitted to use dynamic values for these While it is permitted to use dynamic values for these ports to allow multiple endpoints in a single device ??ports to allow multiple endpoints in a single device ??

1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (4/6)Implementation Issues (4/6)

When messages are sent on the reliable When messages are sent on the reliable H.245 control channel, more than one H.245 control channel, more than one message may be sent in a single packet as message may be sent in a single packet as long as whole messages are sent; there shall long as whole messages are sent; there shall be no fragmentation of H.245 messages be no fragmentation of H.245 messages across packetsacross packets

1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (5/6)Implementation Issues (5/6)

RTP data in an IP packetRTP data in an IP packet

IP headerIP header UDP headerUDP header RTP headerRTP header RTP payloadRTP payload

For saving bandwidth, multiple RTCP For saving bandwidth, multiple RTCP message may contain in one UDP packetmessage may contain in one UDP packet

1996/2/131996/2/13 Amy, Mei-Hsuan Lu CML/CSIE/NTAmy, Mei-Hsuan Lu CML/CSIE/NTUU

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Implementation Issues (6/6)Implementation Issues (6/6)

Unless otherwise specified, the aligned Unless otherwise specified, the aligned variantvariant PER PER encoding of ASN.1 shall be encoding of ASN.1 shall be used for all ASN.1 specified in H.225.used for all ASN.1 specified in H.225.

The encoding rule of Call Signalling The encoding rule of Call Signalling Messages are specified in Q.931Messages are specified in Q.931