What is EAZ?

CAPI 1.1 was originally designed for the German ISDN network (1TR6). In 1TR6 a dialled number can include an extra digit to indicate which extension or service it requires. For example, if the ISDN number is 6050047, different devices can all be connected to this number and be 'listening' for calls on different EAZs. EAZ 1 might be a Bulletin Board Service, EAZ 2 a fax machine and so on. In this way, a single ISDN number can support a number of different devices, and a user can select these devices based on an EAZ extension to the ISDN number.

 

EAZ values in the German ISDN network (1TR6)

  If you are using the German ISDN network you can use EAZ values for dialling and answering.

 

 

EAZ values in Euro-ISDN

  If you are using Euro-ISDN (the European ISDN network protocol), EAZ values are not available. (A similar but separate concept, subaddressing is available in Euro-ISDN via CAPI 2.0.). However, because EAZ values are an integral part of CAPI 1.1 there has to be a way of mapping EAZ values to standard Euro-ISDN concepts.

Outgoing calls :

EAZ values are ignored and play no part in outgoing calls.

Incoming calls :

In Euro-ISDN a subscriber can assign more than one ISDN number to an ISDN line. For example, an ISDN line could have the numbers 6050047 and 6050048. Each of these numbers can be used to dial the ISDN line. These numbers are referred to as Multiple Subscriber Numbers (MSN). Up to 10 MSNs can be assigned to each basic rate ISDN line. In CAPI 1.1, to differentiate between these incoming numbers, each of the numbers is mapped to an EAZ value. For example 6050047 could be mapped to EAZ 3. When a user dials 6050047, the CAPI 1.1 system regards it as an incoming call on EAZ 3. Therefore KlasDrive must be configured to answer calls on EAZ 3.

 

 

EAZ to MSN mapping

  1. How do you map MSN values to EAZ values? There are three standard ways of mapping MSN values to EAZ values, detailed below.
  2. Most ISDN cards come with a mapping utility that provides this function. Examine the ISDN card literature to locate this mapping utility.
  3. Some ISDN cards set the last digit of the incoming MSN value to an EAZ value. For example, an incoming number 6050047 would be mapped automatically to EAZ 7 because the last digit is 7. KlasDrive must be configured to answer calls on EAZ 7 to answer this call.
  4. Some ISDN cards set all incoming MSN values to EAZ 0. Any incoming number will be mapped automatically to EAZ 0. KlasDrive must be configured to answer calls on EAZ 0 to answer any of these incoming calls.
  5. Only one copy of KlasDrive can listen for calls on a particular EAZ at any one time, but different EAZ values can be used simultaneously. For example, EAZ 1 and EAZ 2 can be used to listen for calls simultaneously, but only one application can listen for calls on EAZ 0 at any one time. KlasDrive must be configured on the correct EAZ value to be notified of an incoming call.

    To set KlasDrive EAZ value for incoming calls see the Answering section in the Setup dialog box. EAZ only applies to CAPI 1.1. In CAPI 2.0, subaddress values are used for in-dialling services. In Euro-ISDN subaddress values are totally independent from EAZ values.