Point to Multipoint link configuration for ePMP products

Summary:
This article will help you in configuring a Point to Multipoint link using ePMP AP (Access Point) and SM (Subscriber Module)

Products:
ePMP product line i.e. ePMP 1000, ePMP 2000, ePMP Force 100/110/130/180/190/200, ePMP Elevate – 802.11n
ePMP 3000/3000L, Force 300 series - 802.11ac

Solution:
The devices could be accessed by connecting the LAN to the Laptop LAN port via default IP address 192.168.0.1/24 if it is an AP or 192.168.0.2/24 if it is an SM.
The device could always be reached locally via IP address 169.254.1.1/24.
Login to the web GUI using the default username ‘admin’ and password ‘admin’.

Access Point:
Go to Quick start > Main tab:
Enter the Device name and SSID.
The SSID will be displayed on the SM while scanning to identify the AP.
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Click on image button to go to the next tab.
Radio tab:

  1. Select the Country of operation (if not locked).
    Driver Mode: TDD or TDD PTP
    TDD for point to multipoint links
    TDD PTP to point to point links
  2. Select Maximum number of SM registrations allowed for this AP.
  3. Select the Maximum range as per the farthest SM.
  4. Select the channel selection.
    Manually channel can be selected based on spectrum analyzer results on the AP and the SM.
    ACS can be selected to allow the AP to choose the best frequency available at its location, irrespective of the spectrum results on the SM. ACS scan for the best channel prior to the link establishment. Once the link is established it will stop scanning and will stay on the selected frequency.
  5. Channel bandwidth can be selected based on the capacity required, 10 for minimum and 80 for maximum, keeping in consideration the impact of interference which is maximum at 80 MHz and minimum at 10 MHz.
  6. With the manual channel selection selected above you will get an option to select the frequency from the drop-down list.
    When selecting a DFS frequency, Alternate frequencies must be selected to allow the AP to hop when a radar signal is detected on the primary frequency.
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On the Network tab, we will be able to configure the IP address for the radio.
You can select from the Static and DHCP options.
With Static option, we can manually enter the IP address, subnet mark, gateway, DNS server.
When selecting the DHCP option the radio automatically receives the above information from the DHCP server.
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The Security tab allows us to configure the authentication to allow only the desired SM to connect to the AP.
For example: when we use a WPA2 option, we can configure the WPA2 pre-shared key. This key must match the WPA2 pre-shared key configured on the SM to allow it to authenticate and register.
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At last, click on Finish setup.

Subscriber Module:
Go to Quick start > Main tab:
Enter the device name. This is to differentiate the SMs.
Select the Radio mode as subscriber module.
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Radio tab:
The SM will automatically follow the country code configured on the AP.

  1. Driver mode should be TDD when the AP is configured as TDD or TDD PTP (for a PTP link).
    ePTP Slave mode should be used when the AP is configured in ePTP Master mode.
  2. Configure the preferred AP. Note that the SSID, security type and WPA2 pre-shared key (in case of WPA2) configured on the AP should match parameters configured in this column.
  3. Select the frequency and the channel bandwidth configured on the AP.
    Note that if all the frequencies are selected or unselected the SM will scan all the frequencies.
    image

On the Network tab the Network mode can be selected NAT/Bridge/Router.

  • NAT: The SM acts as a router and packets are forwarded or filtered based on their IP header (source or destination). The SM translates IP addresses between the Wireless and Ethernet interfaces.
  • Bridge: The SM acts as a switch, and packets are forwarded or filtered based on their MAC destination address.
  • Router: The SM acts as a router and packets are forwarded or filtered based on their IP header (source or destination) using specific Static Routes and IP Aliases configured by the operator.
    The Static IP address, Subnet mask, Gateway and DNS server configuration can be done here or the IP assignment could be set to DHCP to allow the SM receive these configuration parameters from DHCP server via AP.
    image

On the Security tab, if the preferred AP is configured, it will look like the screenshot below:
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If the preferred AP is not configured, the tab will look like the screenshot below:
We can select the desired security option RADIUS/Open/WPA2.
For example: If we are using WPA2 the WPA2 pre-shared key must be entered, and it should match the key configured on the AP.
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At last, click on finish to exit the setup.
To check if the SM is scanning the AP go to Monitor-Wireless tab on the SM:
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Verify the AP with the SSID and MAC address.
Check for the registration state message and criteria for any errors.
The SM will stay with hold-off state and the Tx power will be off until the link is established with the AP as shown below:
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Note:
• The modes differ among the 802.11n and 802.11ac radios.
• The max MCS support by 802.11ac devices is DS-MCS-9 while by 802.11n devices is MCS-15.
• The spectrum analyzer depends on the model of the radio. On some devices there are live spectrum analyzers and others require the radio mode to be changed. In that case the radio must be accessed locally.
• The channel bandwidth options differs among the devices.

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