You are here: CSP Developer’s Guide: Common Channel Signaling > 12 V5.2 Protocol > 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.
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