Create Subnets for Servers

A subnet is a range of IP addresses in your VPC. You need to create subnets in your VPC, so that you can launch AWS resources, such as server instances and gateways, in the related subnets.

Background information

When you create a subnet, you must specify a range of IPv4 addresses for the VPC in the form of CIDR block (for example, 10.0.0.0/24). Any AWS instances launched within the subnet will communicate over IPv4 only.

Note: If you would like to deploy a High Availability architecture of specific servers, you need to create different subnets for these servers in different Availability Zones.

In this example, you need to create at least five subnets in the VPC. For different purpose, the five subnets are defined as below.

Table 1.
Subnet IPv4 CIDR Block Availability Zone Description
Public Subnet 1

ycm-public-subnet1

 10.0.0.0/24 Availability Zone A

In this subnet, you will later launch instances for the following servers:

  • YCM Server
  • SBC Server 1
  • SBC Proxy Server 1
Public Subnet 2

ycm-public-subnet2

 10.0.1.0/24 Availability Zone A In this subnet, you will later create a NAT gateway.
Private Subnet 1

ycm-private-subnet1

 10.0.2.0/24 Availability Zone A

In this subnet, you will later launch instances for the primary PBXHub Server.
Public Subnet 3

ycm-public-subnet3

 10.0.3.0/24 Availability Zone B

In this subnet, you will later launch instances for the following servers:

  • SBC Server 2
  • SBC Proxy Server 2
Private Subnet 2

ycm-private-subnet2

 10.0.4.0/24 Availability Zone B In this subnet, you will later launch instances for the secondary PBXHub Server.

The following figure shows the architecture in your VPC after you complete this step.

Procedure

  1. Log in to Amazon VPC Console.
  2. On the left navigation bar, click Subnets, then click Create subnet.

  3. In the VPC ID drop-down list, select the VPC you've created for the Cloud PBX. In this example, select ycm-cloudpbx.

    The associated IPv4 CIDRs is displayed under the VPC ID.

  4. In the Subnet settings section, complete the following settings:

    1. Set up the subnet.
      • Subnet name: Enter a name to help you identify the subnet. In this example, enter ycm-public-subnet1.
      • Availability Zone: In the drop-down list, select the desired Availability Zone in which the subnet will be created.
        Note: You should create the subnets for specific servers in different Availability Zones.

        For example, if you would like deploy High Availability architecture for SBC servers, and the subnet for SBC Server 1 is created in Availability Zone A, then the subnet for SBC Server 2 should be created in another Availability Zone.

      • IPv4 CIDR block: Specify an IPv4 CIDR block for the subnet. In this example, enter 10.0.0.0/24.
    2. Click Add new subnet and follow the Step 4 to set up other subnets.
  5. Click Create subnet.

    The new created subnets are listed in the Subnets list.