Aim of the guide

The aim of this guide is to demonstrate a solution for providing telephone communication to a small enterprise or isolated division with a small number (up to 100) of subscribers.

Copper trunks, for which the PBX has FXO ports, are used to connect to the PSTN.

To solve this problem, it is best to use the Eltex SMG-200 IP PBX with one or two M8O submodules installed, each with 8 FXO ports.

It should be noted that in most cases, eight external lines will not be sufficient for comfortable operation of an automatic telephone exchange with 100 internal subscribers.

This document covers the SMG-200 with the M8O module installed in the first slot (ports 1–8). The second slot (ports 9–16) can be fitted with an M8O module, an M8S module, or left empty.

Proposed network diagram

Network diagram

The description of diagrams

The telephony core is SMG-200 IP PBX with M8O submodules.

IP phones are registered on the SMG-200 via a network of Ethernet switches.

Analog phones are connected to IP PBX via subscriber gateways, such as TAU-16.IP.

The subscriber gateway is connected to IP PBX via an Ethernet network. Subscribers are registered on the PBX via SIP.

If only one M8O submodule is installed in the SMG-200, an M8S submodule with 8 FXS ports can be installed in the second slot. Accordingly, 8 analog phones can be connected directly to the SMG-200. 

Used types of Ethernet ports

The following Ethernet interface names are used in this guide:

Port designationPort purposePort requirements
A1SMG-200 IP PBX connection portTrunk port with specified native VLAN
PxIP phone connection portsAccess port with Voice VLAN and PoE
Tx
Ports for connecting analog TAU gatewaysAccess port
M1Port for connecting AWS, which is used to configure and manage an IP PBX and phones.Access port

Used VLANs

In the guide the following virtual local area networks (VLAN) are used.

VLAN nameVLAN purposePorts included in VLAN
Mgm_VlanPBX management

A1 – untagged
M1 – untagged

Data_VlanTelephony signalling and media traffic

A1 – tagged
Px – voice VLAN
Tx – untagged

Traffic restrictions between VLANs

Permissions required for this example.

From \ ToMgm_VlanData_Vlan
Mgm_Vlan
Allow HTTP, HTTPS
Data_Vlan

IP addressing and dial plan

For demonstration purposes, this guide will use the following:

Dial plan:

  1. Internal phones: 
    1. Three-digit dial: xxx
    2. Numbers used in the example: 200 – 299
    3. Numbers 284 through 299 inclusive are assigned to subscribers with analog telephones connected via TAU-16.IP.
  2. PSTN phones: 
    1. Area code (383). Within the area, seven digits: xxxxxxx
    2. Our office has been assigned the following numbers: (383)9741001 – 9741008 
    3. Incoming calls from the PSTN to numbers 9741001 – 9741007 are forwarded to internal 201-207 numbers accordingly.
    4. Numbers 9741007 and 9741008 are used for outgoing PSTN calls for subscribers who do not have a linked local number. Incoming calls to 9741008 are forwarded to internal number 207 (e.g., to the secretary).
    5. The lines for telephone numbers 9741001–9741008 are connected to RJ-11 ports 1 through 8, respectively.
    6. If two M8O submodules are installed and there are more than eight external lines, the remaining lines are connected to ports 9-16 and used for outgoing calls. The configuration is completely similar to port 8.

IP addressing:

  1. Telephony network (Data_Vlan):
    1. Network: 192.0.2.0/24
    2. VLAN ID: 92
    3. Default gateway: 192.0.2.1
    4. SMG-200 IP PBX: 192.0.2.10
    5. TAU-36.IP subscriber gateway: 192.0.2.16
    6. IP phones: 192.0.2.20 – 192.0.2.240
  2. Management VLAN (Mgm_Vlan):
    1. Network: 192.168.1.0/24
    2. SMG-200 IP PBX: 192.168.1.10
  3. Addresses of services:
    1. NTP server: 192.0.2.1

Tables for configuration are available via the link.

Before configuring IP telephony, ensure that the data network is functioning properly. Check the network connectivity.

Equipment configuration

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.

Minimum required configuration

Configuring IP PBX

The SMG-200 IP PBX is configured via a web interface. Default account details:

  • Username: admin
  • Password: rootpasswd

The necessary IP PBX configuration includes the following steps:

Configuring the management interface

Follow the instructions to change the IP settings on the main interface. Specify:

  1. Network name: Mgm_Vlan
  2. IP address: 192.168.1.10
  3. Network mask: 255.255.255.0
  4. Gateway: 0.0.0.0 – the gateway for this interface will not be used.
  5. Disable all services except “Web Management”.

Adding an interface for telephony

Follow the instructions to add and configure an interface for RTP and SIP traffic:

  1. Network name: Data_Vlan
  2. VLAN ID: 92
  3. IP address: 192.0.2.10
  4. Netowrk mask: 255.255.255.0
  5. Gateway: 192.0.2.1
  6. Check the “SIP signaling” and “Forward RTP” boxes.

Configuring network parameters

Follow the instructions to change the used interface gateway to

Configuring date and time

For IP telephony to function correctly, set the current date and time on the device. 

Time and date are configured on an NTP server.

For automatic time synchronization via NTP on SMG-200 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:

  1. Time server (NTP): 192.0.2.1
  2. Time zone: select the required time zone.

Creating an SIP profile

Follow the instructions to create a SIP profile. 

In the “Name” field, enter “SIP subscribers”.

In the “Network interface for SIP” and “Network interface for RTP” fields, select

Creating SIP subscribers

Follow the instructions to create SIP subscribers. When creating, specify:

  1. Number of subscribers: 100
  2. Starting number: 200
  3. SIP profile: SIP subscribers.
  4. Password: 1234

Configuring a DHCP server

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:

  1. Source address: 192.0.2.20
  2. Destination address: 192.0.2.240
  3. Subnet mask: 255.255.255.0
  4. Gateway/router address: 192.0.2.1

Saving the configuration

After completing the initial configuration, it is recommended to save the device configuration.

Configuring the connection to PSTN

To connect the company's telephone network to the public telephone network, it is necessary to configure FXO ports, hotline for incoming calls and routing of outgoing local calls.

Configuring FXO ports for accessing PSTN

Follow the instructions to configure all FXO ports. When configuring, fill in the “Hotline (incoming calls)” fields:

  1. For ports 1 through 6, specify numbers 201 through 206, respectively.
  2. For port 7 and subsequent ports, specify the number 207.

Creating a trunk group

Follow the instructions to create a trunk group. When creating, specify the following:

  1. Name: TG in PSTN.
  2. Group composition: FXO lines.
  3. FXO line: select lines from 7 to the last one.

Configuring routing to PSTN numbers

Follow the instructions to create a prefix in the dial plan. When creating, specify the following:

  1. Name: in PSTN.
  2. Trunk group: TG in PSTN.
  3. Mask: (xxxxxxx|[78][3489]xxxxxxxxx|810x.)

Saving the SMG-200 configuration

Save the device configuration.

Connecting IP phones

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 above settings, they will receive IP addresses automatically.

The first phone turned on will receive the 192.0.2.20 address, the second one will receive the 192.0.2.21 address, and so on.

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-200 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.

Configuring the phone

Follow the instructions to configure the phones.

Fill in the following fields:

  1. Phone number: values from 200 to 267 without repetitions.
  2. Username: value similar to the previous field.
  3. Password: 1234
  4. SIP proxy server: 192.0.2.10
  5. Registration server: 192.0.2.10

Connecting analog phones

Analog phones are connected to the SMG-200 IP PBX via TAU series analog gateways or directly, if M8S submodules are installed.

Configuring the TAU-16.IP analog gateway

The TAU-16.IP analog gateway (referred to as TAU) is configured via the web interface in the example below.

  1. Default IP address: 192.168.1.2
  2. Default username: admin
  3. Default password: rootpasswd


The necessary TAU configuration includes the following steps:

Configuring the connection to the local network

Follow the instructions to configure the TAU:

  1. IP address: 192.0.2.16
  2. Network mask: 255.255.255.0
  3. Gateway: 192.0.2.1

Configuring date and time

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. SMG-200 cannot act as an NTP server.

Follow the instructions to configure synchronization with the following parameters:

  1. Enable NTP .
  2. NTP server address: 192.0.2.1
  3. Allow periodic synchronization.
  4. Synchronization period: 3600

Configuring the SIP profile

Follow the instructions to configure the SIP profile. When configuring, specify:

  1. Operating mode: «Parking».
  2. Proxy address / Registrar address / Use registration 1: 192.0.2.10/192.0.2.10/Check the checkbox.

Creating subscribers

Follow the instructions to create subscribers with numbers 284–299. When creating, specify:

  1. In the “Starting number” field, enter: 284

Specifying subscriber login details

Follow the instructions to specify subscriber login details. In the “1-16” port group tab, go through all subscribers. In the port cards, specify:

  1. Name for authentication/authorization: the value is equal to the value in the “Phone number” field.
  2. Password for authentication/authorization: 1234

Configuring a dialing plan

Follow the instructions to set up a dialing plan. Select “Regular expression dialplan.” In the “Rule:” field, enter “[*#0-9]”

Saving the configuration

All settings are stored in the 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.

Configuring additional functionality

If the dynamic firewall was disabled before starting the configuration, it is recommended to enable it according to the instructions.

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