Transcript Security & Cryptography

Multimedia via Data Networks
Agenda
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IP services in mobile telephony
Voice over IP
(High Definition) Video over IP
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Video on demand
Video conferencing
Download
Integrated Multiservice Networks—
Data/Voice/Video
SNA
Data
Voice
Multiservice Network
PBX
Video
Internet
Packet-Based
Multimedia via Data Networks
GSM/3G Mobile Telephony
Talsarunu tarifi (USD/min)
VoIP un Lattelekom
SIP phones
Basic SIP IP phones below
$100
 802.11 phones
 video phones
 Speakerphones
 PDAs with SIP software
 MAC, Unix, and MSoft.
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Voice Quality Guidelines
Silence Suppression by
Voice Activity Detection
Voice Activity Detection (VAD)
Speech
Silence
Speech
No Cells
Cells
Cells
Fax over IP
H.323 MCU
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Responsible for managing multipoint conferences
(two or more endpoints engaged in a conference)
The MCU contains
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a Multipoint Controller (MC) that manages the call signaling
may optionally have Multipoint Processors (MPs) to handle
media mixing, switching, or other media processing
Multisite Videoconferencing
MCU
Streaming server
A Integrated SIP
Service System
Desktop
SIP clients
H.323
SIPUA
sip323
sipd
Gatekeeper
SIP-H.323
signaling gateway
SIP
Programmable
SIP servers
Conferencing
Hardware SIP phone
sipconf
Unified messaging
sipum
sipgw
SIP-MGCP gateway
rtspd
MGCP
Streaming media
SIP-PSTN gateway
PSTN
Quick-time
Regular telephones
RTSP
ENUM example: Voice
PSTN
Internet
6.5.4.3.2.1.0.8.7.3.4.e164.arpa
4. sip:[email protected]
2. +43 780.*
5. INVITE sip:[email protected]
Telekom
PSTN Switch
1. +43 780 123456
PSTN-IP
Gateway
nic.at43.at
6. INVITE sip:[email protected]
sip:[email protected]
ENUM example: SMS delivery
PSTN
Internet
6.5.4.3.2.1.0.8.7.3.4.e164.arpa
4. sip:[email protected]
2. SMS
via SMPP
5. MESSAGE sip:[email protected]
MO SMS
Center
at43 SMPP
Server
1. SMS an +43 780 123456
nic.at43.at
6. MESSAGE sip:[email protected]
sip:[email protected]
cross-domain call ENUM
ENUM DNS
IN NAPTR 7.3.5.7.3.2.2.4.2.6.0.1.8.7.8.e164.arpa. ?
... NAPTR ... "!^.*!sip:[email protected]!"
fwd.pulver.com
nic.at43.at
SIP
server
DNS SRV lookup
fwd.pulver.com
+878106242237537
SIP
server
sip:[email protected]
session
sip:[email protected]
sip:[email protected]
sip:[email protected]
sip:[email protected]
PBX2PBX using ENUM
+442079025500
PBX
PSTN
+442079025500
Asterisk
Linux PBX
ENUM
+421257296666
Asterisk
Linux PBX
PCM or SIP or IAX or H.323
Internet
PCM or SIP or IAX or H.323
sip:[email protected]
IN NAPTR 6.6.6.6.9.2.7.5.2.1.2.4e164.arpa. ?
ENUM
DNS
... NAPTR ... "!\\+421257296(.*)$!sip:2\\[email protected]!"
Skype
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Based on Kazaa Overlay network
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Unstructured p2p file sharing overlay
Overlay p2p network consisting of ordinary and
Super Nodes (SN).
Ordinary node connects to network through a
Super Node.
Centralized authentication server
Excellent Audio quality based on Internet Low
Bit rate Codec ILBC (http://rfc3951.x42.com/)
iLBC – MOS (Audio Quality) behavior
versus percentage packet loss
Skype
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Skype client listens on configured TCP and UDP ports.
Uses a variant of STUN to identify the type of NAT and
firewall.
Usage of TCP port 80 enables client to reach super node
even through firewalls.
Call signaling is done over TCP, messages are preferably
transported over UDP.
In the presence of NAT or firewalls, calls between caller
and callee are routed by an intermediate node
All Skype messages are encrypted.
HD Video resolution
HD video size
1440
HDV
1080
1280
1920
1080i HD
720p HD
704
4CIF/
FullD1 (SD)
720
576
352
320
288
240
CIF
(SD)
digvid
1080
1.2 High Quality Digital Video Technologies
HDTV
Resolution
Bandwidth
Delay
Uncompressed
1080i
(1920x1080 30fps)
1~1.5Gbps
100msec
MPEG2
720p
(1280x720 60fps)
20~80Mbps
1~2 sec
10Mbps
2~3 sec
250Mbps
100msec
30Mbps
~300msec
5~6Mbps
1~2 sec
H.264
Uncompressed
SDTV
DV
MPEG2
480i
(720x480 30fps)
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Video Streaming Over the Network
Bandwidth
10Gbps
10Mbps
5Mbps DVD
1Gbps
HD
QHD
100Mbps
SD
50Mbps
WMV
MPEG4
1.5Mbps
H.263
128Kbps
MPEG1
H.261
25Mbps
DV
MPEG2
Lab Tests
LDK-6000
PDP-502MX
SMPTE 292M
Centaurus
10 GigE
UltraGrid
Sender
Back-2-back tests:
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Video: 720p
Duration: 10 min
RTT: 70 µs
MTU: 8800 bytes
1.485 Gbps
Centaurus
10 GigE
RTP/UDP/IP
SMPTE 292M
UltraGrid
Receiver
Results:
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No loss or reordering
1198.03 Mbps
throughput
Total 10,178,098 packets
sent and received
HDV over IP system
HD Camcorder
HD Display
…
TS
Packets
MPEG-2 TS
IEEE1394
Interface
IP Network
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…
Sender
…
Packetizer
RTP Packets
Packetizer and
MPEG2 Decoder
Receiver
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i2CAT experiences with HD
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2001 Open Opera
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Live transmission of an Opera (La Traviata) from Liceu Opera House to a cinema both
in Barcelona to compare spectators feelings.
After several tests with experts, we concluded that the only acceptable quality was
uncompressed high definition
CINESA Diagonal
Liceu Opera House
HDSDI (1,5 Gbps )
SDI
HDSDI
Media
Gateway
MPEG2
(10 Mbps )
IP Multicast
i2CAT
UNIVERSITIES (UPC, UdG, UdL)
Video Packetization and IP Transport
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RTP packetization is based on:
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``RTP Payload Format for Uncompressed Video’’, RFC 4175
Ladan Gharai and Colin Perkins
RFC 4175 covers packetization of various video formats:
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Supports range of formats including standard & high definition
video
Interlaced and progressive
RGB, RGBA, BGR, BGRA, YUV
Various color sub-sampling: 4:4:4, 4:2:2, 4:2:0, 4:1:1
RTP
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RFC 1889: RTP: A Transport Protocol for Real-Time Applications
RFC 2250: RTP Payload format for MPEG1/MPEG2 Video
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RTP Payload contain integral number of MPEG transport
packet (188byte).
Suggest several MPEG picture fragmentation rules.
RTP Header fields for MPEG2 Video
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