Access Restrictions

Directory Numbers and Feature Numbers

The user always dials a directory number when using the ICX-AlphaCom. The ICX-AlphaCom looks up the directory number in the directory number table, where it finds a feature number. All exchange services are activated via the feature numbers, e.g. conversations, group calls, activation of transfer etc.

The feature number tells the ICX-AlphaCom which major service the user wants. In addition, many features have a feature index which selects one of many possible hardware (or software) instances to use. Examples: physical stations, audio programs, conferences.

A directory number is thus described both by the major information feature number, and by the minor information feature index. The ICX-AlphaCom offers two levels of access restrictions:

on feature, i.e. either a station is allowed to select audio program, or it’s not.
on directory numbers, i.e. you can determine which audio programs a certain station is allowed to activate, and which it can’t activate. It is possible to have several directory number which have identical feature number + index. The most useful example is several users sharing one physical station.

Restricted Access to Features - "Class of Service"

To be able to limit a station's access to specific features, the ICX-AlphaCom groups the system features into 16 different Classes of Service (COS); class 1 to 16. Main article: Class of service

Each class of service defines a list of features (using feature number) to which access is possible. Each station is assigned to one of the 16 classes, and has access only to the features defined in the class. Features dialed outside connection, features during connection and help menu features can all be restricted or allowed in this way. The features included in any Class of Service can be changed by programming. A feature can be included in none, one or several classes.

Class of Service after Factory Default

Class of Service 1
- This class is given to all stations except one during Factory Default. The most common user features are included in Class 1.
Class of Service 15
- This class is intended to be used for External Telephony. It includes all features that we recommend should be available for incoming callers via the telephone.
Class of Service 16

All features that can be reached from a station are included in Class of Service 16. The station with the lowest physical address (physical position 1, directory number 101), is set to class 16 after Factory Default. This station is called the Super User and is intended for the system administrator. We recommend that there is a display station connected to this physical position. From this station it is possible to enable/disable features for Class of Service 1.

Restricted Access to Directory Numbers (Single Feature/Index)

When COS cannot give the degree of control you want, you have the possibility to control single directory numbers. This makes it possible to define groups of stations that are not allowed to listen to particular programs, use the telephone line etc. You can then for example make several companies share one exchange. By setting up one group of stations for each company and remove the Call Station feature from the stations’ COS you can prevent calling between the companies and then give each station access to call their own group.

This restriction can be set up in two ways: allowing a few stations access or blocking a few station from access.

Block most - allowing a few stations access

You can block a feature in general by taking it out of the normal stations’ COS. Then you can open up for a few stations by putting them in a group, and use this group as “give access to” group in the directory number table.

Allow most - blocking a few stations from access

Set the feature open by including it in the normal stations’ COS. Then you make a group of those stations that should not have access, and use that as “block access from” group in the directory number table.

Additional Information

The access limitations on directory numbers are applied also if a call goes via Call Forwarding. It’s not possible to “sneak in” a back door! The restrictions on directory numbers are applied after the COS check.
If you put a station in another COS, it obeys the access rules for that COS, i.e. gives yet another dimension to access control. A consequence of this is that it’s possible for a single directory number to be associated with two groups, one to allow a few stations access, and another to block a few, as these rules will be applied for different COSes.

Group Access Level

Hidden Numbers on Single-touch Keys

Access restrictions are normally used to prevent the dialing of certain numbers. The ICX-AlphaCom’s way of interpreting digits “hides” long numbers behind short ones, for instance 99 will hide 991 (connects to 99 always). This can be used to create directory numbers which can only be accessed from DAK keys configured with AlphaPro. Thus a feature can be generally open in COS, but only certain stations can reach certain numbers via their DAKs.

Directory numbers programmed on DAKs are treated differently than directory numbers dialed from the keyboard. The “hidden” numbers are then accessible.

Event Handler Used for Call Restrictions

Access Related to Specified Stations

The event handler can restrict execution of the action string to certain “related to” stations. This can e.g. be used to restrict door opening to just a few stations.

Restriction Related to Specified Stations

The event handler can also use the “related to” information to recognize certain forbidden combinations. The events “conversation - outgoing” and “conversation - incoming” can activate a C_KEY action to cancel a conversation immediately.

User Defined Event Indirect Operation

There is a special feature “Event Trigger” which can be controlled via COS the normal way. Stations that are blocked by COS to some feature, e.g. conference, can have access to Event Trigger. In this way certain stations can be allowed to do a CONNECT action which are not subject to normal restrictions.