PPL Component for RAS - 0x00A0

Overview

This section includes configuration bytes, PPL Events, and Event Indications for the PPL Component RAS.

Table 8-1 Configuration Bytes

Important! By default, the configuration byte is set to zero and PPL event indications are sent to the host. If it is set to anything other than zero, PPL event indications are not sent to the host.

AIB (00 01 0d 03 ff ff ff) is valid for the following PPL Event Requests and Indications which are not related to any active calls: RRQ, URQ, RCF, UCF, RRQ FAIL, URQ FAIL, RRJ, URJ, BRQ, GRQ. Other PPL Event Requests and Indications have a valid Span Channel.

The configuration byte for RAS uses the AIB with FFFFFF as the span channel.

Table 8-2 PPL Event Requests

Table 8-3 PPL Event Indications

See the API Reference for information on ICB 0x51 Soft Register All Switch-Initiated Messages.

Refer to PPL Component Addressing in the PPL Component Information chapter in the API Reference.

Table 8-4 PPL Timer

Getting Gatekeeper Discovery and Registration

You can query the Status Gatekeeper status using the PPL Data Query (0x00DE) message. The response returns information about the Gatekeeper discovery and registration status along with the Gatekeeper IP and Port.

Example:

Sp ch comp.Id entity

00 0F 00 DE 00 00 01 00 01 0D 03 FF FF FF 00 A0 08

This query is valid for only the RAS PPL Component (0x00A0). The AIB used is the expanded span channel with the values equal to 0xFFFF 0xFF. Any other PPL Component and span channel values will be rejected with an invalid address response (0xD2).

Example: The following is a sample response from the Excel platform to the host:

00 18 00 DE 00 01 01 00 10 PPL Data Query, Node 1, ACK

00 01 0D 03 FF FF FF Span Channel 0xFFFF, 0xFF

00 A0 RAS Component

08 Entity = Gatekeeper Status

02 Status = 2

0A 0A 0E 02 Gatekeeper IP Address

06 B7 Gatekeeper Port

The status values are as follows:

0 - undiscovered

1 - discovered, unregistered

2 - registered

0xFF - Invalid

The invalid status is returned if the query is made when the RAS PPL is in a non-stable state.

For status values of 1 and 2, the response is the same as the example above. For status values of 0 and 0xFF, the status response is the following:

00 12 00 de 00 01 01 00 10 00 01 0d 03 ff ff ff 00 a0 08 00

00 12 00 de 00 01 01 00 10 00 01 0d 03 ff ff ff 00 a0 08 ff

This response differs from the first response above in that the Gatekeeper IP Address and port are not included in the response.

Continuous Attempts at Gatekeeper Discovery and Registration

The Excel platform can continuously attempt H.323 gatekeeper discovery and registration at the following points in time:

• Initial gatekeeper discover

• Initial gatekeeper registration

• Subsequent registration after the initial registration is successful

Initial Gatekeeper Discovery

When the initial discovery attempt fails, the Excel platform checks Configuration Byte 2. If the value is non-zero, the value stored in the RAS PPL Timer 1 is loaded into a generic PPL timer. When this timer expires, the Excel platform attempts to re-discover the gatekeeper. (The default value for the timer is three seconds.)

If this attempt fails, the Excel platform repeats the process continuously until the Excel platform receives a successful response from the gatekeeper or the host disables the functionality by clearing Configuration Byte 2.

Each time a discover attempt fails, the Excel platform sends the host a PPL Event Indication of GRQ Fail (0x1D). Just the event is sent – no ICB. The Excel platform also sends an ACK to the original PPL Event Request of GRQ. Even though the host sends a single PPL Event Request message, it receives multiple ACKs.

Initial Gatekeeper Registration

When the initial registration attempt fails, the Excel platform checks Configuration Byte 2. If the value is non-zero, the value stored in the RAS PPL Timer 1 is loaded into a generic PPL timer. When this timer expires, the Excel platform attempts to re-register with the gatekeeper. (The default value for the timer is three seconds.)

If this attempt fails, the Excel platform repeats the process until the Excel platform receives a successful response from the gatekeeper or the host disables the feature by clearing Configuration Byte 2. If the host disables the feature, the PPL returns to the Stable Undiscovered
State 1, which is the normal operation of the PPL.

Each time a registration attempt fails, the Excel platform sends the host a PPL Event Indication of RRQ Fail (0x1E). Just the event is sent – no ICB. The Excel platform also sends an ACK to the original PPL Event Request of RRQ. Even though the host sends a single PPL Event Request message, it receives multiple ACKs.

If Configuration Byte 2 is disabled (value 0) and the Excel platform does not get an RCF message in response to the RRQ message, the Excel platform goes into undiscovered mode.

Subsequent Gatekeeper Registration (Lightweight RRQ)

Once the initial registration is successful, the IP Signaling Series 3 card enters the registered state. In this state, the Excel platform periodically sends Lightweight RRQ messages to the gatekeeper to maintain registration. The interval of the Lightweight RRQ messages is determined by the gatekeeper in the RCF response.

The gatekeeper responds to the RRQ message with an RCF message. If the Excel platform receives no response, under normal circumstances (prior to this new functionality) the IP Signaling Series 3 card unregisters itself and returns to the undiscovered state.

In this new continuous registration mode, the Excel platform checks the value of Configuration Byte 2. If this value is non-zero, the value stored in the RAS PPL Timer 1 is loaded into a generic PPL timer. (The default value is three seconds.). When this timer expires, the Excel platform attempts to re-register with the gatekeeper. If this attempt fails, the Excel platform repeats this process continuously until the Excel platform receives a successful response from the gatekeeper or the host disables the feature by clearing Configuration Byte 2.

Each time a registration attempt fails, the Excel platform sends a PPL Event Indication of RRQ Fail (0x1E) to the host.

If Configuration Byte 2 is disabled (value 0) and the Excel platform does not get an RCF message in response to the RRQ message, the Excel platform goes into undiscovered mode.

Examples of Host Messages

The following are examples of the PPL Configure and PPL Timer Configure API message used for the new gatekeeper discovery/registration mode.

Table 8-5 PPL Configure Message with RAS PPL Configuration Byte 2

Table 8-6 PPL Timer Configure Message with RAS PPL
Timer 1