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Call Routing

NANP North American Numbering Plan

NXX-NXX-XXXX
N=[2-9] X=[0-9]
Area Code, Prefix, Subscriber number
LATA - Local Access Transport Area

N11 Codes

211
Community Information and Referral Services
311
Non-Emergency Police and Other Governmental Services
411
Local Directory Assistance
511
Traffic and Transportation (US) Weather and Traveler information (Canada)
611
Repair Service
711
Telecommunications Relay Service (TRS)
811
Access to One Call services to protect pipelines and utilities (US) non-urgent health (Canada)
911
Emergency

900-NXX

900 numbers are used for premium services, it is common to block all 900 numbers.

Voice Gateway Setup / Licensing

show licence
H.323 / SIP / CUCME / SRST uses dial-peers for call routing
POTS dial-peers are used to connect PSTN Voice-ports
VoIP dial-peers are used to connect IP end-points
IP Phones registered to CUCME are POTS dial-peers
dial-peers are used to develop the dial plan

Dial-peer matching

  • Incoming called number (terminate inbound DID calls)
  • Answer-address (used to route calls based on calling number)
  • destination-pattern, inbound or outbound match on calling number
  • port - matches the associated voice-port
uses longest match
#R1

dial-peer voice 1 pots
	incoming called-number 1...
	direct-inward-dial
	
dial-peer voice 2 voip
	destination-pattern 2...
	session-target ipv4 10.1.1.2
	
#R2

dial-peer voice 1 pots
	incoming called-number 2...
	direct-inward-dial
	
dial-peer voice 2 voip
	destination-pattern 1...
	session-target ipv4 10.1.1.1

Dial-Peer Translations

  • Prefix
  • No digit strip
  • Forward digits