[Asterisk-Dev] Wildcard X100P

[Mikael Andersson]

Mikael Andersson  -- <> wrote on den 27 april 2004 13:40:

> 
> I guess nobody has tried that ?
> 
> Here in Sweden we don't have FSK Callerid from our Telco. I guess
> that goes for all of Scandinavia. 
> 
> I am not a programmer, but I wonder, is it hard to fix a driver for
> the wildcard x100p that can detect DTMF callerid ? 
> 
> /Mike
> 
> 

I'm replying to myself here just to add som technical details on the Swedish Telco CID system:

Soorry if the mail is long.

This is how CallerID is sent to the customer from the telcos in Sweden. Is it possible to get the x100p to understand this ?



-----snip----

DEFINITIONS

Z interface is a term used in this document for all types of analogue 2-wire interfaces at the network operator side of analogue subscriber lines delivering the PSTN service. The Z interface can be located in local exchanges (LEs), remote concentrators or multiplexors or in network terminating units (NTs) or terminal adaptors (TAs) located at the user´s premises.

An international number consists of a Country Code (CC) and a National (Significant) Number (N(S)N). An example: 46 8 7132920, where CC = 46 and N(S)N = 8 7132920.

A national (significant) number consists of a trunk code (TC) and a subscriber number (SN) e.g. N(S)N=8 7132920, where TC=8 and SN=7132920. An area code consists of a national prefix (0) and the trunk code (TC).

The Calling Number is the information designating the calling user who initiated the call.

The Redirecting Number is the information sent in the forward direction when a call is diverted, indicating the diverting user from which the call was diverted or, in case of multiple diversions, the diverting user from which the call was last diverted.

A restricted number is a number to be restricted from presentation. The reasons for restricting numbers are as follows:

♦ the calling user (and/or the diverting user) has required that his number shall not be presented.

♦ the calling user has invoked a number presentation restriction on a call-by-call basis

♦ other reasons.

Symbols according to table 1 are used in the protocol for information transfer in clause 4 and 5.



Table 1

A	Start code for a Calling Number (DTMF character “A” ) 
B 	Start code for an information code (DTMF character “B” ) 
C 	Stop code (DTMF character “C” ) 
D	Start code for a Redirecting Number (DTMF character “D” ) 
Sn	DTMF digits “0” to “9” 
-	Inter-digit pause between all DTMF digits/characters 
N	Integer < 15 
S1-S2...Sn 0 + the national significant number in case of national call 
00 + the international number in case of international call 
T1-t2 Information code where tn is DTMF digits “0” to “9”


TRANSFER OF NUMBER INFORMATION

The user number S1S2...Sn shall be sent at the Z interface according to the alternatives below. Symbols are defined in table 1.
For an ordinary (non-diverted) call, 1a or 1b shall apply.
For a diverted call, 2a or 2b shall apply.

1a) For an ordinary call, the Calling Number shall be transferred as
D-S1-S2...Sn-C

1b) For an ordinary call, the Calling Number shall be transferred as
A-S1-S2...Sn-C

2a) For a diverted call (see figure 1), the Redirecting Number (b) shall be transferred as D-S1-S2...Sn-C

2b) For a diverted call (see figure 1), the Calling Number (a) and the Redirecting Number (b) shall be transferred as A-S1-S2...Sn-D-S1-S2...Sn-C


NO TRANSFER OF NUMBER INFORMATION

In two cases defined below, the number information according to clause 4 shall be replaced by an information code t1-t2. 

1) If no number is available, the information code shall be transferred as
B-t1-t2-C where t1-t2 = 0-0

A restricted number (see definition in clause 3) shall not be presented and the information code shall be transferred as
B-t1-t2-C where t1-t2 = 1-0

Normal call set-up

(1) The line is in idle state and the user´s terminal equipment is on-hook. Idle polarity at the Z interface shall be 0 V (earth) at a-wire and –48 to –52V DC at b-wire.

When number information shall be sent, the system shall ...

(2) seize the line and perform polarity reversal. The voltage shall be the same as in (1) but the polarity shall be reversed.

(3) send number information according to clause 4 or information codes according to clause 5. The sending of the information shall start not sooner than 200 ms but not later than 1000 ms after the polarity reversal.

(4) perform polarity reversal back to idle polarity as in (1).

(5) send the first ringing signal not sooner than 80 ms after the polarity reversal in (4), but not later than 1000 ms after the end of the stop code “C”.

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