IMG 1010 - Logical Interface

The Logical Interface object is used to configure specific functionality on each of the interfaces located on the back of the IMG (CTRL, Data, Sig). By configuring or enabling certain fields in the Logical Interface object either the Ethernet Redundancy via Smart Probing feature or the VLAN Tagging feature can be configured.

Smart Probing

Using Logical Interface object along with the Probe Endpoint object and IP Network object the Smart-Probing feature can be configured. The Smart-Probing feature enhances the fault tolerance of the IMG by sending a Gratuitous ARP to each of the network endpoints. If any of the endpoints do not respond to the ARP within a specified amount of time, the IMG will automatically switch-over the interface or port to its redundant pair. The Logical Interface object enables the feature and sets the interval/threshold values. Refer to IMG 1010 - Ethernet Redundancy via Smart Probe for more information on the Smart-Probing feature.

VLAN Tagging

VLAN Tagging functionality can be configured on a single IP address using the IP address object -or- the interfaces labeled Data and Sig can each be configured to add a VLAN tag to every packet that is transmitted through them. The interface labeled CTRL cannot be configured to add VLAN tags to every packet being transmitted but individual IP addresses can be configured to add VLAN tags that are sent out the CTRL interface. For more information on the VLAN Tagging feature refer to the IMG 1010 - VLAN Tagging topic.

Use the information below to configure the Logical Interface object.

Accessing this Pane

Dialogic IMG EMS > Logical IMG > Physical IMG > Network > Logical Interface

Maximum Objects

Up to three Logical Interface objects can be created. One for the CTRL interface, one for the Data interface, and one for the Signaling interface.

ClientView Pane

Field Descriptions

Interface

Select from drop down menu which interface to configure the Smart-Probing feature on. Selections include the following:

Control (Default) – Configures Smart-Probing feature on the CTRL 0/1 interface combination located on the rear of the IMG. Select Control from drop down menu when configuring the CTRL 0/1 interface.

The VLAN Tagging field below will not be visible when the Control selection from the drop down menu is chosen.

Data- Configures Smart-Probing and/or the VLAN Tagging feature on the Data 0/1 interface combination located on the rear of the IMG. Select Data from drop down menu when configuring the Data 0/1 interface.

Signaling- Configures Smart-Probing and/or the VLAN Tagging feature on the Sig 0/1 interface combination located on the rear of the IMG. Select Signaling from drop down menu when configuring the Sig 0/1 interface.

Probe Detection (Default=Disabled)

To enable the Smart Probing Feature on the Interface selected above select Enabled from the drop down menu.

Probe Interval (Default = 2 seconds)

If the Smart-Probing feature is enabled, the IMG will send a Gratuitous ARP to a network endpoint. If a response is not heard within the interval configured the IMG will send out a second ARP and then a third. The IMG will continue sending Gratuitous ARPs until it reaches the setting on the Probe Threshold field displayed below. To change the number of seconds, click in the Probe Interval field and select a time in seconds from the drop down menu. (Range = 1-60 seconds)

Probe Threshold (Default = 5 counts)

If the Smart-Probing feature is enabled, the IMG will count the number of Gratuitous ARP's sent to the network endpoint. Once IMG reaches the threshold configured it will automatically switch-over to the Standby Port. To change the number of counts, click in the Probe Threshold field and select from the drop menu a different count value. (Range = 1-10 Counts)

The IMG can get into a scenario where a switchover occurs on one of the interfaces (Ctrl, Data, Signaling) because none of the Probe Endpoints on that particular interface are responding to the IMG's ARP requests. After a specific interval of time the GCEMS will initiate a switchover of interfaces (i.e. Data0 to Data1 interface). The interval of time before the first switchover is calculated as follows:

(Probe Interval * Probe Threshold) = (2*5)=10 seconds

Using the value calculated above, the first switchover would occur after not receiving an ARP response for 10 seconds. However the interface (Data 1) that the IMG switched to is also not getting a response from the Probe Endpoints. A second interval of time is calculated which is the time of the second switchover. See below:

(Probe Interval * Probe Threshold) + Probe Interval = (2*5)+2 = 12 seconds

Knowing that the first interval was 10 seconds, the second will be at 22 seconds and the third at 34 seconds. The switch-overs will continue at 12 second intervals until the network issue is resolved. The switching back and forth is referred to as the Ping Pong effect.

VLAN ID (Range = 0 - 4094)

Configuring the VLAN ID field will embed a VLAN Tag into any outgoing packets that are communicating through the interface configured above. Click in the VLAN ID field and a Range Dialog box will appear. Enter an ID in the ID: field of this Range Dialog box. The ID's range from 0 - 4094. A VLAN ID of 0 signifies the VLAN tagging functionality is disabled. Refer to the IMG 1010 - VLAN Tagging topic for more information. A maximum of 20 VLANs can be created over the three interfaces on the rear of IMG.

The VLAN ID field is not visible when Control is selected in the Interface field above. VLAN tagging is not supported on the Control Interface in this object. To enable VLAN tagging through the Control interface, the VLAN tag needs to be configured on each IP address that is communicating through the Control Interface. This is achieved through the IMG 1010 - IP Address object.

VLAN Priority

The VLAN Priority field is not visible until the VLAN ID field is modified to a value other than 0. Once a value is configured the VLAN Priority field appears. Select from drop down menu the priority being given to this VLAN Tag. The priority given will indicate a priority level that will be given to the packet. A priority of 7 is highest and priority of 0 is the lowest. These values can be used to prioritize different classes of traffic (voice, video, data, etc). Refer to the IMG 1010 - VLAN Tagging topic for more information.

Monitoring Fields

The fields described below are fields used to monitor the interfaces and display their status in the fields. These fields are all shaded in yellow

Active Port

Displays the active port of the interface selected in the Interface field.

Active Link Status

Displays whether the Active ports link is up or down.

Standby Port

Displays the standby port of the interface selected in the Interface field.

Standby Link Status

Displays whether the Standby ports link status is up or down.

Switchover Reason

Displays status of why the switchover from Active Port to Standby Port or from Standby Port to active port has occurred. Queries are displayed as follows:

None – No switchover has occurred

Link Failure – Automatic Switchover has occurred due to the link status of the interface selected going down.

Probe Failure – Automatic Switchover has occurred due to Smart-Probing feature reaching its count Threshold of failed ARPS. At this point the IMG initiates an automatic switchover which is displayed as Probe Failure.

Host Initiated – Switchover has occurred due to a manual switchover being executed by user.