IIUC Notes – Voice Ports and Dial Peers


More of my IIUC study notes.  As always, feel free to correct.  I really need to have a real post, don't I?

show voice port summary

  • Shows the voice ports available for use
R1#show voice port summary
                                          IN       OUT
============== == ============ ===== ==== ======== ======== ==
50/0/1         1      efxs     up    up   on-hook  idle     y
50/0/1         2      efxs     up    up   on-hook  idle     y
50/0/2         1      efxs     up    up   on-hook  idle     y
50/0/2         2      efxs     up    up   on-hook  idle     y
50/0/3         1      efxs     up    up   on-hook  idle     y
50/0/4         1      efxs     up    up   on-hook  idle     y
50/0/5         1      efxs     up    up   on-hook  idle     y
  • An ephone-dn shows up as efxs, so all these are ephone-dns.
  • Channels are numbered 0-23; timeslots are numbered 1-24

FXS Ports

  • Connect to end stations like analog phones and fax machines
  • Signaling
    • Ground start: New connections started by grounding wires
      • Typically used when tied to PBXes
    • Loop start:  New connections started by sending DC voltage
      • Default
      • Typically used when connecting to analog devices
  • Call progress tones
    • Audible tones to let the user know the status of a call
      • Dial tone, busy, call waiting, etc.
      • Different in each geographical area
  • Caller ID
    • Identifies the name and number that calls on this line should appear

R1(config)#voice-port 0/0/0
R1(config-voiceport)#signal loopStart <- Use loopstart signaling
R1(config-voiceport)#cptone PE <- Uses CP tones from Peru
R1(config-voiceport)#station-id name Corporate Fax
R1(config-voiceport)#station-id number 5551212

FXO Ports

  • Connects to CO or PBX
  • A lot of the same configurations as FXS ports
  • Two additional to discuss
    • dialt-type:  DTMF or pulse dialing
    • ring:  The number of rings to wait before answering; usually 1
      • Think of allowing a home user to answer the phone before the fax machine picks up

R1(config)#voice-port Reverse Phone 0/0/1
R1(config-voiceport)#dial-type dtmf <- touch tone
R1(config-voiceport)#ring 3 <- wait 3 rings before answering

Digital Voice Ports

  • Unlike analog voice ports, digital voice ports must be configured to function with the network to which they are attached.
  • Voice and WAN interface cards (VWICs) provide digital voice port
  • show controllers t1
  • Framing:  defines how to format the frames
    • SF or ESF
  • Line coding:  encodes the signal in a way to maintain sychronization
    • AMI or B8ZS
  • Clock source:  defines who dictates the clocking
  • Signaling:  channel signaling
    • CAS:  use ds0-group
      • Ports show up as 0/0:1, where 0/0 is the physical port and 1 is the ds0 group
    • CCS:  use pri-group
      • Ports shows up as 0/0:23, where 0/0 is the physical port and 23 is the signaling channel (16 in E1)

R1(config)#isdn switch-type primary-5ess <- If using CCS
R1(config)#controller t1 0/0
R1(config-controller)#framing esf
R1(config-controller)#linecode b8zs
R1(config-controller)#clock source line <- get clocking from provider
For CAS:
R1(config-controller)#ds0-group 1 timeslots 1-24 type fxo-loop-start <- Using FXO loopstart signaling
For CCS:
R1(config-controller)#pri-group 1 timeslots 1-24 <- assumes signaling from CCS and ISDN switch-type

Dial Peers

  • "Routing" for phone numbers
  • Tells a voice gateway where to send calls based on dialed number
  • Two types dial peers
    • POTS:  Traditional connections like T1 and analog phone lines
    • VOIP:  Connections to an IP address
  • show dial-peer voice summary

R1(config)#dial-peer voice 1101 pots
R1(config-dial-peer)#destination-pattern 1101  <- This number…
R1(config-dial-peer)#port 0/0/0  <-  …is on this FXS port.

R1(config)#dial-peer voice 1102 pots
R1(config-dial-peer)#destination-pattern 1102  <- This number…
R1(config-dial-peer)#port 1/0:23  <-  …is on this T1 PRI port.

R1(config)#dial-peer voice 1103 voip
R1(config-dial-peer)#destination-pattern 1103  <- This number…
R1(config-dial-peer)#session target ipv4:  <- …is at this IP address…
R1(config-dial-peer)#codec g711ulaw  <- …and use this codec when you get there.