VoIP

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VoIP Gateway/Gatekeeper Design Requirements

• An Examination
• Ricardo Estevez
• CS 522 / Computer Communication
• Fall 2003

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Big Picture
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Precise Picture
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Gateway and Gatekeeper Signaling
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Gatekeeper and Directory Gatekeeper Signaling
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Gateway/Gatekeeper Design Requirements

• Many areas to examine, lets discuss the
  following
• Zoning
• Normalization
• Traffic Engineering
• High Availability

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Gateway/Gatekeeper Design Requirements

• Zoning
• NPA-NXX
• Numbering Plan Area NPA - Prefix
• Several gateways form a zone
• 1 or more zones can register with a single
  gatekeeper
• Gatekeeper will choose zone based on prefix
  lookup
• Gatekeeper will choose terminating gateway based
  on priority

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Gateway/Gatekeeper Design Requirements

• Normalization
• Use Directory Gatekeepers (DGK) for global
  routing
• Use Gatekeeper for local routing
• Traffic Engineering
• Grade of service
• Traffic load
• Trunk size

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Gateway/Gatekeeper Design Requirements

• High Availability
• Gateway declares its degree of availability via a
  Resource Availability Indicator (RAI)
• RAI thresholds are set
• A gatekeeper will favor a gateway for call
  handling RAI threshold is not exceeded
• Increases call completions
• Alternate Gatekeeper and DGK

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References

• Durkin, James F. Voice-Enabling the Data Network.
  Cisco Press Indianapolis, IN. 2003.
• ISBN 1-58705-014-5