You are here: CSP Developer’s Guide: Internet Protocol > 9 H.323 Software > PPL Component for RAS - 0x00A0

PPL Component for RAS - 0x00A0

Overview

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

Table 9-1 Configuration Bytes

Byte (Hex) | Function | Option (*default)
--- | --- | ---
0x01 | Toggle PPL indication Enable/Disable | 0x00* - enable
0x02 | Enable/Disable continuous discovery and registration attempts with the gatekeeper | 0x00* - disable 0x01 - enable

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 9-2 PPL Event Requests

PPL Event Request ID | Purpose
--- | ---
0x01 | Send Gatekeeper Request (GRQ)
0x02 | Send Registration Request (RRQ)
0x03 | Send Unregistration Request (URQ)
0x04 | Send Bandwidth Request (BRQ)

Table 9-3 PPL Event Indications

PPL Event Indication ID | Purpose
--- | ---
0x01 | Admission Confirm (ACF) Indication
0x02 | Admission Reject (ARJ) Indication
0x03 | Admission Request (ARQ) Indication
0x04 | Bandwidth Confirm (BCF) Indication
0x05 | Bandwidth Reject (BRJ) Indication
0x06 | Bandwidth Request (BRQ) Indication
0x07 | Disengage Confirm (DCF) Indication
0x08 | Disengage Reject (DRJ) Indication
0x09 | Disengage Request (DRQ) Indication
0x0A | Gatekeeper Confirm (GCF) Indication
0x0B | Gatekeeper Reject (GRJ) Indication
0x0D | Info Request Ack (IACK) Indication
0x0E | Info Request NACK (INAK) Indication
0x0F | Info Request (IRQ) Indication
0x10 | Info Request Response (IRR) Indication
0x14 | Resource Available Confirm (RAC) Indication
0x15 | Resource Available Indicate (RAI) Indication
0x16 | Registration Confirm (RCF) Indication
0x17 | Request In Progress (RIP) Indication
0x18 | Registration Reject (RRJ) Indication
0x1A | Unregistration Confirm (UCF) Indication
0x1B | Unregistration Reject (URJ) Indication
0x1C | Unregistration Request (URQ) Indication
0x1D | Gatekeeper Request (GRQ) FAIL Indication
0x1E | Registration Request (RRQ) FAIL Indication
0x1F | Admissions Request (ARQ) FAIL Indication
0x20 | Disengage Reject (DRQ) FAIL Indication
0x21 | Bandwidth Request (BRQ) FAIL Indication
0x23 | Unregister Request (URQ) FAIL Indications
0x24 | XRS Indication. Message Not Understood.

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 9-4 PPL Timer

Timer ID (Hex) | Timer Name | Default Value
--- | --- | ---
0x01 | RAS PPL Timer 1 | 3 seconds

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 CSP 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 CSP 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 CSP 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 CSP attempts to re-discover the gatekeeper. (The default value for the timer is three seconds.)

If this attempt fails, the CSP repeats the process continuously until the CSP 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 CSP sends the host a PPL Event Indication of GRQ Fail (0x1D). Just the event is sent – no ICB. The CSP 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 CSP 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 CSP attempts to re-register with the gatekeeper. (The default value for the timer is three seconds.)

If this attempt fails, the CSP repeats the process until the CSP 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 CSP sends the host a PPL Event Indication of RRQ Fail (0x1E). Just the event is sent – no ICB. The CSP 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 CSP does not get an RCF message in response to the RRQ message, the CSP 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 CSP 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 CSP receives no response, under normal circumstances (prior to this functionality) the IP Signaling Series 3 card unregisters itself and returns to the undiscovered state.

In this continuous registration mode, the CSP 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 CSP attempts to re-register with the gatekeeper. If this attempt fails, the CSP repeats this process continuously until the CSP 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 CSP sends a PPL Event Indication of RRQ Fail (0x1E) to the host.

If Configuration Byte 2 is disabled (value 0) and the CSP does not get an RCF message in response to the RRQ message, the CSP 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 9-5 PPL Configure Message with RAS PPL Configuration Byte 2

Header | 00 17 00 D7 00 00 FF
--- | ---
AIB (Range of Channels) | 01 02 0D 03 FF FF FF 0D 03 FF FF FF
Component ID | 00 A0
Entity | 01
Number of Config. Bytes | 01
Config. Byte Number | 02
Data | 00 - Disable 01 - Enable

Table 9-6 PPL Timer Configure Message with RAS PPL
Timer 1

Header | 00 17 00 CF 00 00 FF
--- | ---
AIB (Range of Channels) | 01 02 0D 03 FF FF FF 0D 03 FF FF FF
Component ID | 00 A0
Timer Type | 01
Timer ID | 01
Value | 0x0000 - 0xFFFF 01 2C - Default (300 in units of 10ms=3 seconds)

See Programmable Protocol Language.
A programmable software component that uses PPL state machines that can be modified with the PPL Tool.
The Registration, Admission, and Status messages communicated between two H.323 entities for example between an Endpoint and a Gatekeeper.
In PPL, a condition that, when met, drives a state machine (PPL Component) from one state to another, by invoking an associated Primitive. In PPL files, an Event is marked by an arrow and text.
See Address Information Block.
A condition that, when met, drives a state machine from one state to another. A condition that drives a Component out of its current state by invoking an associated primitive.
Range of channels provided by T1 or E1 transmission service. A physical span is a group of channels taking up a single physical wire. A logical span is a group of channels taking up less than a single logical wire, or carried over more than one physical wire.
An H.323 entity on the network that provides address translation and controls access to the network for H.323 terminals and other end points. The gatekeeper may also provide other services to the endpoints such as bandwidth management and locating gateways.
Admission Request
Negative acknowledgement to a message.
See Information Control Block.
Internet Protocol. Part of the TCP/IP family of protocols used to route messages and tracks the addresses of nodes.
The point in the Excel platform where a DS0 connects to a network. Also known as a "socket."
Positive acknowledgment to a message
A 32-bit address, used in IP routing, which includes a Network address identifier assigned by a central authority and a Host ID (an end station identifier assigned by a LAN administrator).
ITU-T standard defines a set of call control, channel setup, and codec specifications for transmitting real-time voice and video over networks that do not offer guaranteed service or quality of service.
The condition of a component at a given instant. The current "context" of a PPL object, such as Idle, Seizing, Answered. In PPL files, a State is represented by a circle.
A computer, attached to the Excel platform through an RS-232 or Ethernet link, from which you run the telecommunications application that controls the Excel platform.