4. Incoming Call Processing

Pace ISDN TA is able to support several services identified by a DTE channel ID. When an incoming call is presented, Pace ISDN TA detects if the TA is compatible with the incoming SET-UP matching parameters in the following order :

Called local number,

Called local subaddress,

ISDN Information Elements (IE) :

Bearer Capability (BC),

Low Layer Capability (LLC),

High Layer Capability (HLC).

Pace ISDN TA is able to support several local numbers, several local subaddresses, and several ISDN services (BC, LLC, HLC).

An global local number and local subaddress could be attached to Pace ISDN TA. In this case Pace ISDN TA will only react to incoming calls matching called number and/or subaddress.

A specific local number or/and local subaddress can be attached to a service and to DTE channel through a configuration command (AT#). For selecting a specific service and a DTE channel, the calling party should address the appropriate number or/and subaddress.

Use of addressing (number or subaddress) for routing incoming calls to the right DTE channel is strongly recommended. Nevertheless, this is not always possible (only one local number assigned to the terminal, no subaddress transmitted by the network, no subaddress due to interworking) . If the same number and subaddress are assigned to several DTE channels or if there no called address or/and no subaddress the DTE channel selection uses a priority parameter. An ‘incoming call priority’ value is assigned to each DTE channel. If during the selection several DTE channels are matching the incoming SET-UP, the DTE channel with the highest priority is selected. Priority ranges from 0 to 254, 0 being the highest priority. If the priority parameter is set to 255, the corresponding DTE channel is never selected by an incoming call. This allows the User to avoid incoming calls to be routed to services not supporting them or not available.

At factory set-up all the local numbers are empty. The subaddresses and priority are as following :

 

DTE Channel ID	Subaddress	Priority
1 async transparent PAD to PAD	1	10
6 telephony	6	255
7 async/sync	7	28
8 async transparent V.14	8	26
10 async transparent V.120	10	16
11 X.25/PAD B channel	11	12
13 async transparent 2xB	13	16
Analogue port 1 (POTS1)		40
Analogue port 2 (POTS2)		40

The local numbers are up to 23 digits. The subaddress is up to 4 digits.