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Overview of Circuit and Packet Switch.
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Overview of Circuit and Packet Switch Circuit Switch# Dedicated transmission path# Continoues transmission of data# Message are not stored# The path is established for entire conversation# Call set-up delay, negligible transmission delay# Fixed Bandwidth transmission# no overhead bits after call set-up# prefer for long data message (minimum time connect) Packet Switch# No Dedicated path# Transmission of packet, packet maybe stored until delivered# Route established for each packet (for datagram packet switching)# packets transmission delay# Network maybe response for individual packets# Dynamic use of bandwidth # Overhead bits in each packet# Prefer for short data message (variance time connect)# more efficiency in Bandwidth
Voice over Internet Protocol (VoIP) IP Telephony Signalling IP telephony
KOMPONEN Standard H.323 • Inter-Operabilitas-VoIP
Komponen H.323 • Terminal Hubungan komponen H.323 dan lingkungannya
SIP Protocol • SIP is An application layer signaling protocol that defines initiation, modification and termination of interactive, multimedia communication sessions between users. • Components of SIP Protocol : 1. SIP User Agents User Agent Clients (UAC) User Agent Servers (UAS) 2. SIP Servers Proxy server Redirect server Location server Registrar server
SIP Messages ►SIP messages are defined for two formats: • requests, sent from a client to a server : 1. INVITE 4. BYE 2. ACK 5. CANCEL 3. OPTION 6. REGISTER • responses, sent from a server to a client. 1xx: Provisional 4xx: ClientError 2xx: Success 5xx: Server Error 3xx: Redirection 6xx: Global Failure
Mean Opinion Score (MOS) Method is used to define voice quality in IP network based on ITU-T P.800 Recommendation Relation between MOS and R Factor
One Way Delay = coder processing delay(compression and algorithmic delay) + packetization delay+ serialization delay + network delay Delay Analysis
It is a variation of packets incoming due to the difference of the packets’ path Jitter Analysis Packet Loss Analysis Packet Loss is usual thing in IP network. In VoIP network, packets are sent using RTP (Real Time Protocol) and UDP (User Datagram Protocol).
Throughput Analysis • Throughput means the effective data transfer rate, which measured in bps. • Throughput = Packet receive Time between first and last packet Mbps (Mega bit per second)
R Factor And MOS Computation • R Factor Computation R = 94.2 – Id– Ief • Ief = 7 + 30 ln ( 1 + 15e) • Id = 0.024 d + 0.11(d – 177.3) H(d – 177.3) • MOS = 1 + 0.035 R + 7x10-6 R(R-60)(100-R)