developing cable telephony solutions michael metzger executive director, marketing mindspeed...
TRANSCRIPT
Developing Cable Telephony Solutions
Michael MetzgerExecutive Director, MarketingMindspeed Technologies, Inc.
Agenda
• Introduction• Voice over Cable Architectures• Cable Standardization Bodies• High Density Cable Gateway SoC Solutions• EMTA SoC Solutions• What’s Next in Voice over Cable?
Introduction• VoIP over Cable is experiencing strong
growth within North America • Forecast of more than 17 M Voice over Cable
subscribers in 2008• VoIP over Cable completes MSOs offering for
triple-play voice, video, and data services• Fundamental change in architectures
moving to Packet-based networks from analog Voice over Cable
Voice over Cable – Current Architecture
PSTN
IP Network
Headend Class 5Switch
NetworkInterface Terminal
Cable Modem
• Analog voice traffic placed on cable medium, and connected to PSTN using traditional Class-5 switch
Next Generation – VoIP over Cable
PSTN
IP Network
Media GW,Signaling GW
CMTS
EMTA
Voice Traffic
Data/Voice Traffic Call Mgmt
Server
• True VoIP over Cable, packetized in converged MTA solutions
• Migration to all IP networks
SBC
IP Network
WiFi
PacketCable
• Specification forum focused around detailing the architecture for next-generation IP Cable networks
• For Voice, PacketCable details:o QoSo Securityo PSTN & IP Interconnecto Lawful Intercepto Reliability
IPCablecom Standardization Process
ITU-T
SCTETCC
(Japan)ETSI
CableLabs(projects)
ECCA(requirements)
Vendor Vendor Vendor
Global Standards(J.160 – J.174)
Regional Standards
Contributors
PacketCable – Timeline
• Rel 1.0o Architectural framework for Packet-based Cable
networks (1999)
• Rel. 1.5o Added new voice codecs, fax relay (2005)
• Future Releaseso IMS architecture & mobilityo Call control moving to SIPo New voice and video codecs
PacketCable – QoS
• Quality of Service in PacketCable networks must at a minimum be equal to that of the PSTNo Fundamental requirement to drive adoption
• Major Factors affecting QoS for voice:o Voice Compression Technologyo Packet Losso Packet Latency/Delayo Echo Cancellation
• To ensure high QoS, SoCs must address the above
Typical High-Density Gateway Solution
Control and Signaling
Host Operating System
Media Stream Processing
InternalMemory
N x DSP
DSP Resource Manager
Voice Channels
Signaling Stacks
Control Applications
TDM
Ethernet
Media Stream Processing sub-system offloads host CPU
Ethernet
SoC Solutions for High Density Gateways
PSTN IP
SoC
SoC SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
Ethernet Switch
SoC
TSI
Ethernet PHY
OC-3
VoIP to TDM (with/without encryption)
Media Forking for CALEA (with/without encryption)
Transcoding (IP-IP)(with/without encryption)
SoC Architectures for High Density Gateways
VoiceDSP
TSI
Packet Processor
SoCVoiceDSP
VoiceDSP
VoiceDSP
Security
Ethernet TDM
Memory
DSP Functions: Codecs
• Limited uplink speed demands complex voice codecs
• Echo Cancellation G.168-2002/4• Required G.711, recommended G.729e,
G.728 (Rel. 1.0)• Added required iLBC, BV-16 (Rel. 1.5)• Future release
o Wide-Band Codecso Wireless Codecs
Example of Wireline/Wireless Codec: SMV
• Selectable Mode Voice Codec (SMV): Standardized for CDMA2000• G.711 Equivalent Voice Quality• Music Detection• Efficient Rate Determination Algorithm: Average Bitrate ~ 4kbit/s• 4 coding rates: (full-rate:8.5kb/s, half-rate: 4.0kb/s, quarter-rate:
2.0kb/s, eight-rate: 0.8kb/s)
Output bit stream
Encode with 4.0kb/s bit-rate
Encode with 2.0kb/s bit-rate
Encode with 0.8kb/s bit-rate
M U X
Input speech
Encode with 8.5kb/s bit-rate
VAD
Additional parameters extraction
Logic of rate determination
Mode requirement
RDA module
DSP Functions: Intelligent Transcoding
• Increasing demand for Voice transcoding with migration to an all IP network
• Dynamic prediction algorithms prevent the degradation of voice quality inherent in typical G.711 transcoding schemes
• Roundtrip delay critical for voice quality over an IP network is significantly minimized
• No echo cancellation required
Fax & Modems Transport
Required Packet & DSP functions:• Transmit V.90 and 14.4 kbit/s FAX (over
G.711)• T.38 Fax Relay
o 40 ms frame sizeso Packet redundancy
• Synchronization of end-points: less than 0.25 frame slips per minute
Security Processing
• PSTN security is based around the assumption that there is a direct dedicated link between the user and the central officeo In PacketCable networks, shared medium is used
• As such, cryptographic methods are used to provide security in PacketCable for call privacy
• Optional implementationo 128-bit AES encryptiono MMH/SHA-1 for message authentication
Packet Cable Voice Payload Encryption
IP UDP Voice payload Authentication
Authenticated Portion
(MMH)
Encrypted Portion (AES)
RTP
5 x 9s Reliability with N:1 Redundancy
Active1
Active 2 voiceActive 3
74mm
SoCMiro
SoCMiro
SoCMiro
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SoCMiro
ADM6326
IDT72V71660
FPGA
Flow
Classifier
74mm
SoC
SoCMiro
SoC
SoCMiro
SoC
SoCMiro
SoC
SoCMiro
SoC
SoCMiro
SoC
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
SoCMiro
ADM6326
IDT72V71660
FPGA
Flow
Classifier
74mm
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
ADM6326
IDT72V71660
FPGA
Flow
Classifier
SoC
SoC
SoC
SoC
SoC
SoC SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
SoC
Ethernet Switch
StandbySoC
Low to Medium Density MTA’s
SHM Voice
DSP core
TSI
MMU
Control & SignalingProcessor
DualEMAC
SoC
CablePHY
Memory
Tele
ph
on
y I
nte
rfaces
EXPANSIONBUS
CSP
1 to N Telephones
Ethernet
Voice & Data Routing
Embedded MTA
Security
USB2.0
Printer or Peripheral
PCIMSPWi-Fi
CSP & MSP ModelN
on
Re
al-
tim
eR
ea
l-ti
me
TDM
Cable Modem
CSPControl & Signaling Processor
MSPMedia Stream
Processor
Virtual EthernetDriver
Single UnifiedMemory
DDRSDRAM
• Deterministic Voice Quality & Data Routing/VPN Performance
o MSP/CSP partitioning for real-time & non real-time processes
• Corner case interoperability & standards compliance
o CODECs & common functions run on MSP
• New/3rd Party Applications does not affect MSP Processing
o CSP hosts applications independent of media stream
o E.g Linux or VxWorks
Telephony InterfacesTelephony Interfaces
Ethernet
Open Source Applications for a CSP
Project Application HomeLinux Kernel 2.6 UNIX OS with integrated
IPSec http://www.kernel.org/
Apache Web Server http://www.apache.org/
Busybox Common UNIX utilities http://www.busybox.net/
Asterisk PBX, IVR, voicemail http://www.asterisk.org/index.php?menu=features
OpenH323 H.323 protocol http://www.openh323.org/
OpenSIP SIP user agent, proxy http://www.gnu.org/software/osip/osip.html
MGCP MGCP implementation http://www.vovida.org
Festival Lite Text-to-Speech engine http://www.speech.cs.cmu.edu/flite/
PPTP Client VPN software http://pptpclient.sourceforge.net/
iptables firewalling subsystem http://www.netfilter.org/
GNU Zebra Routing Protocol Manager http://www.zebra.org
gcc C/C++ Cross compiler http://gcc.gnu.org/
gdb Debugger http://sources.redhat.com/gdb/
Ethereal Network Sniffer (with MND plugin)
http://www.ethereal.com/
KDevelop Flexible IDE http://www.kdevelop.org/
Development Tools Telephony Core Networking
What’s Next in Voice over Cable?
• Mobility o Support cellular handset/WLANo Wireless/Wireline Transcoding in Cable GW
• Call control mechanismso TGCP SIP
• Migration to IP V6• Integration of Session Border Controllers functions
into Cable GW• Adoption of IMS Architecture• Instant messaging (IM)