External Gateway


Use this pane to specify external SIP or H.323 gateways from which the IMG may receive an incoming call. To configure a group of gateways, use the Gateway Mask field to validate a range of IP addresses.


Accessing this Pane:

Dialogic IMG EMS-> External Network Elements-> External Gateways-> External Gateway



Related Topics:

Adding an External Gateway


Maximum External Gateway Objects:

1024 per EMS


Click on Technical Notes link for technical information when configuring the External Gateway.


External Gateway Pane 10.3.x - 10.5.x



External Gateway Pane 10.5.x + with Transport Type = TLS




Field Descriptions:


A unique name entered that identifies the specific external gateway.


Gateway Signaling Protocol:

H.323 (default) - Gateway uses H.323 Protocol for signaling.

SIP - Gateway uses the SIP protocol for signaling


Gateway Address Type

Gateway IP Address (default) - Gateway is identified by use of IP address. (IPV4)

Host Name (SIP only) - Gateway is identified using hostname and domain. For example (gw1.dialogic.com)


Gateway IP Address

If the Gateway Address Type is Gateway IP Address, this field specifies the IP Address of the External Gateway.


Gateway Mask

Use this field to configure the IMG to accept calls from multiple gateways with one entry. The Gateway Mask in conjunction with the Gateway IP Address field determines the range of IP Addresses from which the IMG will accept calls. If the Incoming IP Address -ANDed- with the Gateway Mask equals the Gateway IP Address -ANDed- with the Gateway Mask then the call will be processed.



In regards to outbound calls, only the specific IP address in the Gateway IP Address field is used.

Examples of Gateway IP Address/Subnet Mask entries

1. Only the IP address specified in the Gateway IP Address field is accepted. This is the default.

Gateway IP Address: (default)

Gateway Mask:


2. IP address ranging from to will be processed

Gateway IP Address:

Gateway Mask:


3. IP address ranging from to will be processed

Gateway IP Address:

Gateway Mask:


4. To accept calls from any gateway:

Gateway IP Address: ANY

Gateway Mask:



Gateway Host Name (SIP Only):

If the Gateway Address Type is Host Name, this field specifies the Host Name of the External Gateway. To look up a gateway based on Host Name you must have a DNS Server configured.


Gateway Transport Type:

This can vary for different gateways and does not need to match the default IMG Transport Type.

TCP (default) - Use Transmission Control Protocol to communicate with the gateway.

UDP (SIP Only) - Use User Datagram Protocol to communicate with the gateway.

TLS (SIP Only) - Use Transport Layer Security encryption on top of TCP. If TLS is selected, a Secure Profile field will appear. See Secure Profile: (10.5.1) below.


IMPORTANT NOTE: If the SIP Invite is greater than 1500 bytes TCP OR TLS is required (UDP will truncate message).


Gateway Remote Port:

The port used for communication with the remote gateway.


Gateway Registration Required (SIP Only):

This field indicates if the IMG must register with the gateway. Applies to SIP Gateways only.


Registration Expiration Interval (sec) (SIP Only):

Use this field to control the registration refresh interval. Applies to SIP Gateways only.

Default = 3600 second

Range = 10-7200 seconds


SIP Profile:

This field has a drop down menu displaying all the SIP profiles created. See SIP SGP Profile for more information.


Secure Profile: (10.5.1):

This field has a drop down menu which will display all the Secure Profiles created for TLS security. Select the Secure Profile to be assigned to the gateway. See Secure Profile for more information.


OPTIONS Keep Alive:

Use his field to enable the SIP Options Keep Alive (Busy Out) feature on a gateway.

Enable - With this field set to enable the IMG will send periodic SIP OPTIONS messages. If the gateway does not respond to one OPTIONS message the gateway will be considered down or unreachable and attempt to re-route the call to a different gateway.

Disable (default) - The SIP options Keep Alive feature will be disabled


NOTE: If the Options Keep Alive property is enabled, disable it before changing other Properties in the SIP External Gateway object. Then, re-enable it once the other changes have been made. This sequence will insure the IMG is configured correctly.



SIP Options Keep Alive Overview

SIP Options Keep Alive Configure

for more information.


SIP Privacy: (Software10.3.3):

SIP Privacy 10.3.3 Settings


Yes (Default)



Off (Default)




The Trusted and Privacy fields in above table relate to SIP Privacy (10.3.3 Software Only). If using IMG Software 10.5.0 see Configuring SIP Privacy


Object Table Tab:

This table shows all the currently configured External Gateways.