Dial Peers on GW

The automatic digit stripping function is specific to POTS dial peers. VoIP dial peers do not automatically strip digits.
Default codec value for VoIP dial peers is G.729
POTS Dial Peers maps a dial string to a specific voice port. The voice port connects the gateway to the PSTN, PBX, or analog telephone
Multimedia Mail overlap (MMolP) The dial peer is mapped to tie email address of the SMTP server. This type of dial peer is used for store-and-forward fax (on-ramp and off-ramp faxing).

Default inbound Dial peer
Also known as dial-peer zero and cannot be modified or disabled
Apply only to the inbound call leg
Any voice codec:G.729 or G.711 codec
No DTMF relay
IP Precedence 0
Voice Activity Detection (VAD) enabled
No Direct Inward Dial (DID) support
Fax-relay disable
Fax rate voice

Digit manipulation
prefix <digits>     Prefixes the specified digits after any explicitly matched digits are stripped
forward-digits <number>     Strips all but the <number> right most digits
forward-digits all     Forwards all digits
forward-digits extra {inband}     Forwards numbers that appear after the matched portion, if inband is specified these are sent as DTMF tones
no digit strip     Disables default digit stripping on pots dial-peers

Digit manipulation order
1.Num-exp
2.Automatic digit strip only for pots
3.Voice translation profile
4.Prefix digit.
5.Forward-digit

Match inbound calls to inbound dial peer
Called number (DNIS) : This is the call destination dial string and is derived from the ISDN setup message or channel associated signaling (CAS) DNIS
Calling Number (ANI) : This is a number string that represents the origin and is derived from the ISDN setup message or CAS ANI. The ANI is also referred to as Calling Line Identification (CLID).

1. Match DNIS (the dialed number) gw(config-dial-peer)# incoming called-number DNIS_string
2. Match the ANI (the calling number or caller ID) gw(config-dial-peer)# answer-address ANI_string
3. Match the ANI with destination-pattern gw(config-dial-peer)# destination-pattern string !Note: For outbound dial peers, this command is matched against the called number or DNIS strings.
4. Match an incoming POTS call to the port config in the dial peer
5. Match dial peer 0

debug voip dialpeer inout
show dialplan number 012312321
debug voice ccapi inout

About Alexis Katsavras

Working as Freelance Cisco Unified Communications Consultant in the UK. www.NetPacket.co.uk