Aim of the guide

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.

Proposed network diagrams

Description of diagrams

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.

Used types of Ethernet ports

The following Ethernet interface names are used in this guide:

Used VLANs

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

Traffic restrictions between VLANs

The necessary permissions for this example are listed in the table:

IP addressing and dial plan

For demonstration purposes, this guide will use the following:

Dial plan:

1. Internal phones: 
   1. Four-digit dial: хххx
   2. Internal numbers used in the example: 1000 – 1999
   3. Numbers 1701 through 1772 inclusive are assigned to subscribers with analog telephones connected via TAU-72.IP.
      
2. PSTN phones: 
   1. Area code (383). Within the area, seven digits: xxxxxxx
   2. Our office has been assigned the following numbers: (383)9741000 – 9741199 and number 9741888
   3. Incoming calls from PSTN to numbers 9741xxx are forwarded to internal 1xxx numbers accordingly.
   4. The number 9741888is used for outgoing PSTN calls for subscribers who do not have a connected local number.
      

IP addressing:

1. Telephony network (Voice_net):
   1. Network: 192.0.2.0/24
   2. VLAN ID: 92
   3. Default gateway: 192.0.2.1
   4. SMG-3016 IP PBX: 192.0.2.30
   5. TAU-72.IP subscriber gateway: 192.0.2.72
   6. IP phones: 192.0.2.20 – 192.0.2.240
2. Management network (OOB_net):
   1. Network: 192.168.1.0/24
   2. SMG-3016 IP PBX: 192.168.1.30
   3. Default gateway: 192.168.1.1
3. Provider connection network (Provider_Vlan):
   1. Network: 198.51.100.0/28
   2. Provider's IP PBX: 198.51.100.1
4. 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-3016 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 management interface.

1. Network name: OOB_net
2. IP address: 192.168.1.30
3. Network mask: 255.255.255.0
4. Gateway: 192.168.1.1

Configuring an interface for telephony

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

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

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 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:

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 an 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: 1000
2. Starting number: 1000
3. SIP profile: SIP subscribers
4. Password: 1234

Configuring the 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 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.

Creating a SIP interface for accessing PSTN

Follow the instructions to create a SIP interface. When creating it, specify the following:

1. Trunk group:
   1. Name: TG to PSTN.
2. SIP interface:
   1. Name: to PSTN.
   2. Trunk group: TG to PSTN.
   3. Host name/IP address: 198.51.100.1
   4. In the “Signaling network interface” and “Network interface for RTP” fields, select

Configuring the modification of incoming call numbers from PSTN

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:

1. Number mask: (73839741[0-1][0-9][0-9])
2. Modification rule for CdPN/Original CdPN: -------1$

Following the instructions, assign the modification to the trunk group. When creating, specify:

1. Add: CdPN
2. CdPN: Replacement of B-number from PSTN.

Configuring routing to PSTN numbers

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

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

Configuring modifications for calls to PSTN

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.

1. Modification of “local” numbers:
   
   1. Number mask: (xxxxxxx) 
   2. Modification rule for CdPN/Original CdPN: +7383$
2. Modification of long-distance numbers:
   
   1. Number mask: (8[3489]xxxxxxxxx) 
   2. Modification rule for CdPN/Original CdPN: 7$
3. Modification of international numbers:
   
   1. Number mask: (810x.) 
   2. Modification rule for CdPN/Original CdPN: ---$

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.

1. Modification of numbers 1000-1199 to numbers 7941000-7941199 
   
   1. Number mask: (1[0-1][0-9][0-9])
   2. Modification rule for CgPN/RedirPN/Generic/Location: +73839741-$
2. Modification of other numbers to number 9741888
   1. Number mask: (xxxx) 
   2. Modification rule for CgPN/RedirPN/Generic/Location: +73839741888!

Follow the instructions to assign the modification to the trunk group. When creating, specify:

1. Add: CdPN
2. Add: CgPN
3. CdPN: B-number to Е.164.
   
4. CgPN: A-number to Е.164 PSTN.
   

Saving the SMG-3016 configuration

Save the configuration of the device.

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 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.

Configuring the phone

Follow the instructions to configure the phones.

Fill in the following fields:

1. Phone number: values from 1000 to 1700 and from 1773 to 1999 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-3016 IP PBX via TAU series analog gateways.

Configuring the TAU-72.IP analog gateway

The TAU-72.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 local network

Follow the instructions to configure the TAU:

1. IP address: 192.0.2.72
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.

Follow the instructions to configure synchronusation with the following parameters:

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

Configuring 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 1701–1772. When creating, specify the following:

1. In the “Starting number” field, enter: 1772

Specifying subscriber login details

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:

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 "Linear dialing plan." In the "Rule:" field, enter "[*#0-9]"

Saving the configuration

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.

Configuring additional functionality

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