The aim of this guide is to demonstrate a solution for providing telephone communication to a small business or isolated branch office with a medium number (up to 1000) of subscribers.
To connect to PSTN, SIP protocol connections are used via an operator providing a trusted Ethernet interface.
To solve this problem, it is best to use an IP PBX based on the SMG-3016 hybrid platform.
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Logical network diagram | Physical network diagram |
The telephony core is SMG-3016 IP PBX. All examples are provided for the firmware version V.3.406.1
IP phones are registered on the SMG-3016 via a network of Ethernet switches.
Analog phones are connected to IP PBX via subscriber gateways, such as TAU-72.IP.
The subscriber gateway is connected to IP PBX via an Ethernet network. Subscribers are registered on the PBX via SIP.
The following Ethernet interface names are used in this guide:
| Port designation | Port purpose | Port requirements |
|---|---|---|
| OOB | Port for connecting management AWS to IP PBX | Access port |
| A1 | SMG-3016 IP PBX connection port | Trunk port with specified native VLAN |
| Px | Ports for connecting IP phones | Access port with Voice VLAN and PoE |
| U1 | Port for connecting to an IP telephony provider | Access or trunk port |
| Tx | Ports for connecting analog TAU gateways | Access port |
| M1 | Port for connecting AWS, which is used to configure and manage an IP PBX and phones. | Access port |
In the guide, the following virtual local area networks (VLAN) are used.
| VLAN name | VLAN purpose | Ports incuded in VLAN |
|---|---|---|
| OOB_net | PBX management | OOB – untagged |
| Voice_net | Telephony signalling and media traffic | A1 – tagged |
| Provider_Vlan | Link towards the provider network | U1 – tagged or untaged |
The necessary permissions for this example are listed in the table:
| From \ To | OOB_net | Voice_net | Provider_Vlan |
|---|---|---|---|
| OOB_net | Allow HTTP, HTTPS | ||
| Voice_net | Allow SIP, RTP from the A1 host to the U1 host | ||
| Provider_Vlan | Allow SIP, RTP from the U1 host to the A1 host |
For demonstration purposes, this guide will use the following:
Dial plan:
IP addressing:
Tables for configuration are available via the link.
Before configuring IP telephony, ensure that the data network is functioning properly. Check the network connectivity.
SMG has a dynamic firewall enabled by default, which automatically blocks device access in case of multiple unsuccessful authorization attempts. This may be inconvenient during the configuration process. It is recommended to disable the dynamic firewall according to the instructions before starting the configuration. It is recommended to enable the dynamic firewall after completing the configuration for security reasons.
The SMG-3016 IP PBX is configured via a web interface. Default account details:
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The necessary IP PBX configuration includes the following steps:
Follow the instructions to change the IP settings on the management interface.
Follow the instructions to change the IP settings on the main interface. Specify:
For IP telephony to function correctly, set the current date and time on the device.
Time and date are configured on the NTP server.
For automatic time synchronization via the NTP protocol, the NTP server on the ESR router or L3 MES switch with the 192.0.2.1 address is used.
To configure NTP synchronization, use the instructions to specify the NTP server address:
Follow the instructions to create an SIP profile.
In the “Name” field, enter “SIP subscribers”.
In the “Network interface for SIP” and “Network interface for RTP” fields, select ![]()
Follow the instructions to create SIP subscribers. When creating, specify:
In this example, the DHCP server only assigns 221 IP addresses, which is not enough for a thousand phones. Practically, one of two options needs to be chosen:
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IP phones require IP addresses to operate. These can be configured manually on each device or assigned using a DHCP server. Configure the DHCP server according to the instructions.
Specify the following parameters:
After completing the initial configuration, it is recommended to save the device configuration.
To connect the company's telephone network to the public telephone network, it is necessary to configure the trunk to the PBX and configure the routing of incoming and outgoing local calls. For incoming routing, the B number will also need to be modified to connect an external number such as 73831234567 to one of the internal numbers. For outgoing routing, the A number will need to be modified to an external number.
Follow the instructions to create a SIP interface. When creating it, specify the following:
Following the instructions, create a table of modifiers named “B-number substitution from PSTN”.
Following the instructions, create a B-number modification for calls from PSTN in the “B-number substitution from PSTN” modifier table. When creating, specify:
Following the instructions, assign the modification to the trunk group. When creating, specify:
Follow the instructions to create a prefix in the dial plan. When creating, specify:
Follow the instructions to create a table of modifiers named “B-number in E.164”.
Follow the instructions, create three B-number modifications for calls to PSTN.
Following the instructions, create a table of modifiers named “A-number in E.164 PSTN”.
Following the instructions, create two modifications of the A-number for calls to PSTN.
Follow the instructions to assign the modification to the trunk group. When creating, specify:
Save the configuration of the device.
VP-17P and VP-30P phones can be powered by switches using PoE technology or from a 230 V network via personal power supplies.
If the phones are turned on after applying all of the settings above, they will receive IP addresses automatically.
If the MAC addresses of the phones are known (written on a sticker on the back of each device), it is possible to find out the correspondence between the devices and addresses by opening the “Network Services” → “DHCP Server” menu of the SMG-3016 web interface. The list of MAC addresses and IP addresses is located at the bottom of the page in the “Assigned IP Addresses” table.

On the phone, the IP address can be found in “Menu” → ‘Status’ → “Network.”
The IP address of the phone will be needed to configure it via the web interface.
Follow the instructions to configure the phones.
Fill in the following fields:
Analog phones are connected to the SMG-3016 IP PBX via TAU series analog gateways.
The TAU-72.IP analog gateway (referred to as TAU) is configured via the web interface in the example below.

The necessary TAU configuration includes the following steps:
Follow the instructions to configure the TAU:
Since TAU does not have a built-in clock, time synchronization from an external server is required to use real time for monitoring and statistics. For automatic time synchronization via NTP with TAU, an NTP server located on the local network or on the Internet must be available.
Follow the instructions to configure synchronusation with the following parameters:
Follow the instructions to configure the SIP profile. When configuring, specify:
Follow the instructions to create subscribers with numbers 1701–1772. When creating, specify the following:
Follow the instructions to specify subscriber login details. In the ("1-18", "19-36", "37-54", "55-72") port group tabs, go through all subscribers. In the port cards, specify:
Follow the instructions to set up a dialing plan. Select "Linear dialing plan." In the "Rule:" field, enter "[*#0-9]"

All settings are stored in TAU's RAM and will be lost upon reboot if not saved. To save the current configuration, select one of the following items from the main menu: “Network settings”/‘PBX’/“Switch”

and click the “Save” button in the lower right corner.
If the dynamic firewall was disabled before starting the configuration, it is recommended to enable it according to the instructions.