Configuring an AT0 Trunk Group
An AT0 trunk group implements voice communication between PBX users and inter-office users. It is an analog circuit trunk and uses the FXO interface of the PBX to connect to the PSTN through a common telephone line.
Context
Enterprises request PSTN telephone numbers of a certain number, and use common telephone lines as AT0 trunk lines so that enterprise users can share the trunk lines. Outgoing calls occupy one trunk line, and the PSTN telephone number is displayed. After calls are ended, the trunk line is released. Incoming calls reach the PBX through the AT0 trunk, and then the PBX forwards the incoming calls to a PBX user or access number of the enterprise switchboard. The trunk line use efficiency is high, and enterprises do not need to request independent PSTN telephone numbers for all enterprise employees.
An AT0 trunk uses FXO interfaces, so the PBX must be configured with the voice card such as the 4FXS1FXO or 4FXO card providing FXO interfaces.
The PBX can add several trunks of the same type to a trunk group, which are invoked by call routes. Even if there is only one trunk, a trunk group needs to be configured to facilitate trunk management.
The PBX connects to the PSTN through an AT0 trunk group, as shown in Figure 2-21.
Procedure
Step |
Action |
Command |
Description |
|---|---|---|---|
1 |
Enter the system view. |
system-view |
- |
2 |
Enter the voice view. |
voice |
- |
3 |
Create an AT0 trunk group and enter the AT0 trunk group view. |
trunk-group name [ fxo ] |
If an AT0 trunk group already exists, this command directly displays the AT0 trunk group view. |
4 |
Bind a trunk to the AT0 trunk group. |
trunk-at0 slotid/subcardid/portid [ default-called-telno default-called-telno-value | caller-telno [ enterprise enterprise-name ] caller-telno-value | cid-transmit-type cid-transmit-type-value | config-status config-status-value | dial-delay dial-delay-value | dial-mode dial-mode-value | insert-prefix insert-prefix-value | insert-prefix-delay insert-prefix-delay-value ] * |
The default-called-telno parameter is mandatory. You can specify default-called-telno to transmit incoming calls through a trunk to an intra-office user (dedicated access) or access number of the switchboard (switchboard access). By configuring caller-telno, you can specify a number for outgoing calls through the AT0 trunk. Only the outgoing calls that are made using the number can be routed through the AT0 trunk. When the AT0 is unavailable, the outgoing calls that are made using the number specified by caller-telno can be routed through other trunks. NOTICE:
|
5 |
(Optional) Configure the enterprise and DN set to which the AT0 trunk group belongs. |
enterprise enterprise-name [ dn-set dn-set-name ] |
By default, an AT0 trunk group belongs to the enterprise default and DN set DefaultDialPlan. You need to perform this step only when multiple enterprises and DN sets are configured. For details on how to configure an enterprise and a DN set, see Configuring an Enterprise and a DN Set. |
6 |
(Optional) Configure a trunk group circuit selection mode. |
select-mode selectmode-value |
The following circuit selection modes are available:
|
7 |
(Optional) Configure the default number displayed. |
default-caller-telno telno-value |
- |
8 |
(Optional) Configure the description for the AT0 trunk group. |
description desc-value |
- |
9 |
Save the configuration. |
save |
- |
Example
# Create an AT0 trunk group named at0a, bind the AT0 trunk connected to FXO interface 4/0/4 to the AT0 trunk group, and set the default called number to the access number 7200.
<Huawei> system-view [Huawei] voice [Huawei-voice] trunk-group at0a fxo [Huawei-voice-trunkgroup-at0a] trunk-at0 4/0/4 default-called-telno 7200 [Huawei-voice-trunkgroup-at0a] save
Verification
Action |
Command |
Expected Result |
|---|---|---|
Verify the AT0 trunk group configuration. |
display voice trunk-group [ name [ para-value ] ] |
The parameter values in the command output are consistent with the settings. |