V5.2 Call Processing

Overview

Using the API messages only, the CSP supports V5 interface management protocols, and facilitates flexible call processing.

At configuration time, by using the Subscriber ID ICB, which uniquely identifies each subscriber, the host sets up Subscriber IDs by pairing a user port with a V5 ID.

To uniquely identify the source of a call, the CSP checks the status of the V5 Subscriber ID ICB for idle, busy, and blocked states. In the incoming call report, the Request for Service with Data message, the AIB is Expanded Span, Channel (0x0D). The V5 Subscriber ID ICB tells the host who the caller is, and the new V5 Formatted Data ICB carries the Information Elements (IEs) for the L3P PSTN protocol.

The Route Control API message is used for outgoing calls. The host must send the V5 Subscriber ID ICB for the destination subscriber. The physical timeslot is allocated dynamically, either through Layer 4 (for the LE) or from the LE (if the switch is acting as the AN). Only the LE selects the physical timeslot for V5.2. The Route Control response contains the selected logical span, channel. The host never selects the logical span, channel using V5.2. Whether it’s the destination or Layer 4, the host will be told about only the channels that are used for the V5 side of the call. Span, channel selection occur conventionally, unless you use Excel’s Call Control. Consistent with current applications, all call processing messages, including Park Channel, Connect, and Connect to Conference, use the Logical Span, Channel AIB (0x0D).

Important! This release of V5.2 supports LE only.

Important! AN is not supported for V5.2. Any text or illustrations (for example, call flows) indicating the AN side is for clarification purposes only.

Sample Call Flows

This section presents diagrams that illustrate typical call flows.

LE Side: Normal incoming call with subscriber release

LE side: Outgoing call to AN with LE initiating on-hook

LE Side: Outgoing call to subscriber with LE initiating on-hook, but subscriber never hangs up

LE Side: Outgoing call with failed allocation

LE Side: Glare with incoming call having priority

LE Side: Normal call clearing initiated by subscriber with timeslot deallocation options

LE Side: Normal call clearing initiated by the LE side with timeslot deallocation options

LE Side: Incoming call. AN releases before channel allocation

LE Side: Incoming call. Digits received before channel allocation

LE Side: Outgoing call. Cleared locally before allocation complete

LE Side: Outgoing call with Layer 4-initiated PURGE

LE Side: Incoming call with Layer 3-initiated PURGE

LE Side: Outgoing call with received Link Dead
* Message sent for all channels on link
**Message sent for all active calls on link

LE Side: Outgoing call with a received Link Blocking (Non-deferred)
* These messages are sent for all channels on link
**These messages are sent for all active calls on link

LE Side: Outgoing call with a received Link Blocking (Deferred)
*Messages sent on all channels on link

Startup with secondary link alive and primary still not up or dead

Startup with PPL Config. Byte #4 set to 0 (zero)

Startup with PPL Config. Byte #4 set to 1

Startup with PPL Config. Byte #4 set to 2

Received Link Alive while in Alive State

Delete Interface

Delete Interface Forced

Received Add Link message from CFG

Remove Link

Add User Ports

Remove User Ports

Received User Port Block request from Layer 3

Received User Port Unblock request from Layer 3

Received User Port Block request from host

User Port Deferred Block request

Received user Port Unblock request from host

User Port Unblock request from System Management

Link Block request from System Management

Non-Deferred Link Block request

Link Block Indication

Deferred Link Block request

Received Link Blocked request from host

Non-Deferred Link Block request from host

Link Unblock Indication from System Management

Link Unblock request from System Management

Link Unblock request from host

V5 Statistics Query from host, Case 1:

Statistics Query for PSTN, BCC, CONTROL, PROTECTION, LINK Protocols and System Management

V5 Statistics Query from host, Case 2:

Statistics Query for Envelope Layer

V5 Statistics Query, Case 3:

Statistics Query for LAPV

Received Link Status Query

C Channel Status query

V5 Interface Status query

User Port Status request

V5 Interface Restart request

Switchover request from host

Switchover request from System Management

Startup failed and PPL Config. Byte 3 set to 0 (zero)

Startup failed and PPL Config. Byte 3 set to 1 (one)

Link Dead

Switchover fail received from System Management, Case 1:

Both C Channels dead

Switchover fail received from System Management, Case 2:

One C Channel is blocked, and the other C Channel is dead