Configure Embedded Gatekeeper Mode Settings

Embedded Gatekeeper Mode

Allows the system to act as the gatekeeper for WAN and LAN side devices. All WAN or LAN RAS, Q.931, and H.245 messages are processed by the system.

H.323 registration refresh interval

Enter the registration refresh interval or TTL field in the RAS RCF message sent to the WAN or LAN side H.323 client.

The client sends keepalive registrations to reset the gatekeeper client entry from becoming stale and being deleted from the gatekeeper Clients List. Endpoints typically send a keepalive registration before this value.

For example, if you enter 300 seconds, most endpoints will send a keepalive registration at 299 seconds or as soon as 199 seconds. The endpoints keepalive registration interval minus the value set in this field can vary depending on the endpoint vendor.

Range is 30 to 9999 seconds, default is 300.

H.323 registration stale time

Enter the time a H.323 client entry is valid on the system.

Each WAN or LAN side registered H.323 endpoint has a H.323 Clients List entry with registration activity timers to determine if the client is actively sending keepalive registrations messages. When a WAN side client fails to update its registration entry on the system within the time specified in this field, the system removes the client from the H.323 Clients List.

The default range for this timer is two times the H.323 registration refresh interval to 9999. For example, when the H.323 registration refresh interval is set to 300, the range for the H.323 registration stale time is 600 to 9999. Default is 600.

H.460 registration refresh interval

Enter the registration refresh interval for the TTL field in the RAS RCF message sent to the WAN side H.460 client.

The client sends keepalive registrations to reset the gatekeeper client entry from becoming stale and being deleted from the gatekeeper Clients List. Endpoints typically send a keepalive registration prior to this value.

For example, if you enter 30 seconds, most endpoints will send a keepalive registration at 29 seconds and as soon as 19 seconds. The endpoints keepalive registration interval minus the value set in this field can vary depending on the endpoint vendor.

Range is 30 is 9999 seconds, default is 30.

H.460 registration stale time

Enter the time an H.460 client entry is valid on the system.

Each WAN side registered H.460 endpoint has a H.323 Clients List entry with registration activity timers to determine if the client is actively sending keepalive registrations messages. When a WAN side H.460 client fails to update its registration entry on the system within the time specified in this field, the system removes the client from the H.323 Clients List.

The default range for this timer is two times the H.460 registration refresh interval to 9999.

For example, when the H.460 registration refresh interval is set to 30, the range for the H.460 registration stale time is 60 to 9999.

Prevent calls from unregistered endpoints

Select the Prevent calls from unregistered endpoints checkbox to block unregistered LAN-side endpoints from making calls through the device. Calls can still be made from registered clients to unregistered endpoints. Default is disabled.

Send parsed ANNEX O string Outbound

Select the Send parsed ANNEX O string Outbound checkbox so that outbound LAN to WAN Annex O calls will have the host part of the destination address removed.

For example, when the incoming destination address from the LAN is formatted as a H.323 URL 1234@example.com, the outgoing destination address will be parsed and sent as dialedDigits 1234 to the resolved example.com host address.

Enables firewall traversal support by conveying information needed for multimedia communication, such as encryption, flow control, jitter management, preference requests, as well as opening and closing logical channels used to carry media streams. It also defines separate send and receive capabilities and the means to send these details to other devices that support H.323:

• Auto-Direct—Auto-Direct mode allows the system to determine if the WAN or LAN call model needs to be routed or direct.

When two H.323 registered LAN clients place a call to each other, the call model is direct. H.460 WAN clients placing calls will always use a routed call model for signaling and RTP media traversal. If the solution includes two remote locations configured for WAN-side gatekeeper mode or if two public WAN H.323 clients are registered to the system and call each other then, the Embedded gatekeeper allows a direct call signaling model and shortest path RTP media.

•  Gatekeeper Routed—Forces all Q.931 and H.245 messaging through the Embedded gatekeeper. RTP can be sent directly between the clients if both H.323 clients are on the LAN or WAN. H.460 clients always use a routed call model.

•  Gatekeeper Routed, Force RTP through Gatekeeper—Functions like the Gatekeeper Routed option but always forces RTP media traversal through the system.

Sets the port returned in Admission Confirm (ACF) messages. If no Custom Q.931 port is set, the default port of 1720 is used.

Remote NAT devices can intercept H.323 messages and modify these messages which results in call failure. Changing the TCP call setup port to something other than TCP 1720 can help with call completion in these cases. For example, modifying this field to port 5000 modifies the RCF message to instruct the registered WAN side clients to use this port for call signaling. TCP 1720 will still be a system listening port for B2B calls.

Note: Ensure the alternate port is not being used for other services.

Enables TCP keep-alive messages and sets the interval between messages in seconds. If this value is zero, no keep-alive messages are sent.

If no response is received, the TCP stack assumes the connected endpoint is no longer listening, and ends the connection. This field sends TCP keepalives to clients connected to the systems well known TCP 1720 port.

Default is 0 (disabled); the minimum setting is 120 seconds.

Enter a default alias to be added to incoming calls without a destination message in the Q.931 Setup message:

•  E.164

•  H.323

This alias allows the embedded gatekeeper or a LAN/Subscriber-side gatekeeper to route the call to a default endpoint.

For example, when a B2B call is placed to the system and the user only dialed the IP or FQDN of the WAN interface, the system adds this alias to the H.323 call setup message and forwards it to the LAN gatekeeper for call processing. This alias can be any alias actively registered to the LAN gatekeeper.

You may add a H.323 static client in the H.323 Clients List and configure this client as the default alias. The static H.323 client should be locked to prevent the client entry from being deleted.

A typical configuration scenario is to configure this field with an MCU IVR alias or a default MCU meeting room alias.

Default is E.164, no alias is set.