# Editing a digital network interface

The digital network interfaces consist of ISDN and CAS interfaces.

## Basic rate interface BRI-T

A basic access has 2 user information channels at 64 kB/s each and 1 data channel at 16 kB/s (2B+D). On each user information channel (B channel) one call or data connection can be set up regardless of the other B channel.

Table 1. Digital network interface settings (BRI-T)
Parameter | Explanation
Outgoing barred | This network interface is barred for outgoing calls.
Trunk groups | Trunk group allocation
Start B channel | First B channel of this channel group
Last B channel | Second B channel of this channel group
TEI management | “TEI” stands for “Terminal Endpoint Identifier”. The TEI management parameter is used to specify the type of ISDN basic access: P-P (point-to-point): This is the usual connection type (default setting). With the aid of a direct dialling plan the users of the communication system can be reached directly using their DDI number. Note: No additional terminals may be connected at the BRI-T interface in parallel with the communication server. P-MP (point-to-multipoint): Some network providers allow the connection type with multiple subscriber numbers (MSN). Here a DDI number with all the digits of the MSN number has to be created for each MSN number.
Collision detection possibility | Indicates the probability with which collisions can be detected
Collision detection | Collisions will be detected.
Layer 2 reactivation | In some countries BRI-T network interfaces are deactivated once a certain amount of time has elapsed without traffic, and are only reactivated when the communication server once again requests a connection. Layer 2 of the BRI-T network interface can be reactivated periodically every three minutes so that incoming calls are not rejected already at the local exchange after potential temporary interruptions in the U interface. For this, set the Layer 2 reactivation parameter to Special.
Layer 2 CMD / RESP |

## Primary rate interface PRI (E1)

A primary rate access has thirty 64 kbit/s user information channels and one 64 kbit/s control and signalling channel. The B channels can be subdivided into channel groups.

Table 2. Digital network interface settings (PRI)
Parameter | Explanation
Channel group x:
With a primary rate access the B channels can be divided up into channel groups and assigned to different trunk groups.
Trunk group | Trunk group allocation
Hunt mode | Forward/Reverse/None: specifies the search direction inside the channel group
Start B channel | First B channel of this channel group
Last B channel | Second B channel of this channel group
Settings:
Layer 2 CMD / RESP |

## Network interface PRI (T1) (primary rate access)

This is the primary rate access for the public network in USA and Canada. It can be set for the protocols: 4ESS and 5EES (AT&T), DMS100 (Nortel), National ISDN 2 (Bellcore).

This type of primary rate access has 23 B channels and 1 D channel (23B+D).

It is supported only on the 1PRI-T1 cards of a Mitel\ 470 communication server.

## CAS on the primary rate interface

CAS (channel-associated signalling) is a signalling protocol for PRI network interfaces that is used in certain countries (e.g. Brazil). This setting provides audio transmitters and audio receiver for transmitting the signalling information.

Table 3. Digital network interface settings (CAS)
Parameter | Explanation
Outgoing barred | This network interface is barred for outgoing calls.
Trunk groups | Trunk group allocation
Synchronisation member |
Synch state | Status display
Collect call blocking signal | If the provider does not support the methods with the MFC/R2 signal for the recognition of collect calls (default value), the parameter must be set to double answer.
Hunt mode | Forward/Reverse/None: specifies the search direction inside the channel group
Hunt mode | Forward/Reverse/None: specifies the search direction inside the channel group
Start B channel | First B channel of this channel group
Last B channel | Second B channel of this channel group

Parent topic: Incoming call routing
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