CCNP Voice Notes - Call Legs / Dial Peers

Call Legs
Every voice call to be completed must have a minimum of two call legs. An Incoming call leg and an Outgoing call leg.

POTS Call Leg – Connected to a non-VoIP network such as POTS line, PRI, BRI etc.
VoIP Call Leg – Connected to a VoIP network such as SIP, H.323.

Dial Peers 
Destination Pattern – Used to match the called telephone number.
Incoming Called-Number – ONLY Considered on selecting inbound dial-peer when it matches the original dialed/called number.
Answer-address – ONLY Considered on selecting inbound dial-peer when it matches the original calling number. 

Call Number aka DNIS (Dialed Number Identification Service)
Calling Number aka ANI (Automatic Number Identification)

Pattern	Description
0-9 A-D * #	All numbers that exist on the phone keypad.
Plus +	First character designates E.164 number; otherwise it specifies that the digit before occurred one or more times.
Period .	Matches any entered digit
%	The digit before occurred either zero or more times.
?	Repeats the digit before zero or one time. Press ctrl-v to disable context help to enter the ?
Circumflex ^	Indicates a match to the beginning of the string.
$	Matches the null string at the end of the string.
T	Makes router wait till all digits are collected. Means variable length.
Backslash \	Followed by a single character, matches that character.
Brackets [ ]	Indicates a range
Parentheses ( )	Indicates a pattern

Examples

Pattern	Matches
5555	Explicitly matches 5555
555.	Matches 5550 – 55559
555[3-9]	Matches 5553 – 5559
(555)?5	Matches 5 or 5555
5%555	Matches 555 or 55555…555
^5555$	Matches 5555
9T	Matches 9 – 999999999999 until digits are done being entered