Gateway and Trunk Concepts Chapter 07. The Process of Converting Voice to Packet 0.
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Transcript of Gateway and Trunk Concepts Chapter 07. The Process of Converting Voice to Packet 0.
Gateway and Trunk Concepts
Chapter 07
The Process of Converting Voice to Packet
0
Encoding Voice into Binary
mu-law 0 0 1 0 0 1 1 0 is a positive value 1 1 1 0 0 1 0 1 is a negative value
Choosing a Voice Codec
http://www.cisco.com/en/US/prod/collateral/modules/ps3115/ps6024/prod_qas0900aecd8016c6ad_ps3115_Products_Q_and_A_Item.html
RTP and RTCP
– Real-time Transport Protocol• Sequence numbers• Time stamps
• Real-time Transport Control Protocol– Packet count– Packet delay– Packet loss– Jitter (delay variations)
Trunking CME to the PSTN
Trunking CME to Other VoIP Systems
H.323
• The first VoIP
SIP
• Session Initation Protocol– NEXT Generation of H.323
MGCP
• Media Gateway Control Protocol– First true client/server VoIP signaling protocol• “Call agent”
– Not as widely supported as H.323 or SIP
SCCP
• Skinny Client Control Protocol– Only Cisco proprietary protocol in use today– Its function is to provide signaling between the
Cisco Unified Communication Manager and the Cisco IP phones
ITSP (Internet Telephony Service Providers)
• Vonage• Verizon• at&t• Ooma
VoIP ISP in USA (sample list)
• Best• X-Voice• Magic Jack• Nextiva• Avaya• Lingo• Zimbio• NEC• Ooma
• 8x8• Talk Switch• Cisco• ShoreTel• Intalk• Viatalk• VoIP.com• ITP• Vonage
Configuring and Verifying Gateway and Trunk
Chapter 08
Configuring Analog Ports
• FXS• FXO
FXS
Foreign Exchange Station Ports
• Signaling types– Ground start– Loop start
FXO
Foreign Exchange Office
Configuring Digital Voice Ports
• T1 CAS PSTN interfaces• T1 CCS PSTN interfaces
• PBXs use E&M• CAS typically uses loop start
Configuring a T1 CAS PSTN Interface
• Turn to page 253
Configuring a T1 CCS PSTN Interface
• Turn to page 257
Dial Peers (POTS & VoIP Dial Peers)
Voice Call Legs
Configuring POTS Dial Peers
Dial Peer Wildcards
Private Line Automatic Ringdown
• PLAR• FXS PLAR • FXO PLAR
Router Call Processing & Digit Manipulation
Inbound and Outbound Dial Peers
Matching Inbound and Outbound Dial Peers
Failovers & Multiple Voice Paths
Redirecting Operator Calls
Centralizing PSTN Access
Using Translation Profiles
QoS (Quality of Service)
• Bandwidth• Delay– Fixed delay– Variable delay– Jitter (delay variations)– Packet loss
End-to-end delay budget: <150 msJitter: 30 <30 msPacket loss: <1%
Cisco AutoQoS
Advantages over manual QoS configuration• Reduces time of deployment• Provides configuration consistency• Reduces deployment cost• Still allows for manual tuning