Cisco Systems Linksys PAP2, RT31P2

Any one of a set of terminating events triggers the PHONE ADAPTER to either accept the user-dialed

sequence, and transmit it to initiate a call, or else reject it as invalid. The terminating events are:

• No candidate sequences remain: the number is rejected.

• Only one candidate sequence remains, and it has been matched completely: the number is

accepted and transmitted after any transformations indicated by the dial plan, unless the

sequence is barred by the dial plan (barring is discussed later), in which case the number is

rejected.

• A timeout occurs: the digit sequence is accepted and transmitted as dialed if incomplete, or

transformed as per the dial plan if complete.

• An explicit ‘send’ (user presses the ‘#’ key): the digit sequence is accepted and transmitted as

dialed if incomplete, or transformed as per the dial plan if complete.

The timeout duration depends on the matching state. If no candidate sequences are as yet complete

(as dialed), the Interdigit_Long_Timeout applies. If a candidate sequence is complete, but there

exists one or more incomplete candidates, then the Interdigit_Short_Timeout applies.

White space is ignored, and may be used for readability.

Digit Sequence Syntax:

Each digit sequence within the dial plan consists of a series of elements, which are individually

matched to the keys pressed by the user. Elements can be one of the following:

• Individual keys ‘0’, ‘1’, ‘2’ . . . ‘9’, ‘*’, ‘#’.

• The letter ‘x’ matches any one numeric digit (‘0’ .. ‘9’)

• A subset of keys within brackets (allows ranges): ‘[‘ set ‘]’ (e.g. [389] means ‘3’ or ‘8’ or ‘9’)

o Numeric ranges are allowed within the brackets: digit ‘-‘ digit (e.g. [2-9] means ‘2’ or ‘3’ or

… or ‘9’)

o Ranges can be combined with other keys: e.g. [235-8*] means ‘2’ or ‘3’ or ‘5’ or ‘6’ or ‘7’

or ‘8’ or ‘*’.

Element repetition:

Any element can be repeated zero or more times by appending a period (‘.’ character) to the element.

Hence, “01.” matches “0”, “01”, “011”, “0111”, … etc.

Subsequence Substitution:

A subsequence of keys (possibly empty) can be automatically replaced with a different subsequence

using an angle bracket notation: ‘<’ dialed-subsequence ‘:’ transmitted-subsequence ‘>’. So, for

example, “<8:1650>xxxxxxx” would match “85551212” and transmit “16505551212”.

Intersequence Tones:

An “outside line” dial tone can be generated within a sequence by appending a ‘,’ character between

digits. Thus, the sequence “9, 1xxxxxxxxxx” sounds an “outside line” dial tone after the user presses

‘9’, until the ‘1’ is pressed.

Number Barring:

A sequence can be barred (rejected) by placing a ‘!’ character at the end of the sequence. Thus,

“1900xxxxxxx!” automatically rejects all 900 area code numbers from being dialed.