Aastra 480i Administrator's Manual page 211

#
# 0,1,2,3,4,5,6,7,8,9,*,# : matches the keypad symbols
# x
# +
#
# []
#
#
# ()
# |
#
#
# If the dialled number doesn't match the dial plan then the call
# is rejected.
sip digit timeout: 3
# Example dial plans
sip dial plan: "x+#|xx+*"
#sip dial plan: [01]xxx|[2-8]xxxx|91xxxxxxxxxx
#sip dial plan terminator: 1
#-------------------------------------------------------------------
: matches any digit (0...9)
: matches 0 or more repetitions of the
: previous expression
: matches any number inside the brackets
: can be used with a "-" to represent a
: range
: expression grouping
: either or
# set the inter-digit timeout in seconds
# this is the default dial string, note
# that is must be quoted since it contains
# a '#' character
# accecpt any 4 digit number beginning
# with a 0 or 1, any 5 digit number
# beginning with a number between 2 and 8
# (inclusive) or a 12 digit number
# beginning with 91
# enable sending of the "#" symbol to
# to the proxy in the dial string
IP Phone SIP Admin Guide 203