Cas Processing In Voip Switching And Switched Aal2 Pvc Operating Mode; Figure 3-2 Vism Signaling Paths - Cisco Voice Interworking Services (VISM) Installation And Configuration Manual

Signaling Function
You can configure the VISM card to support CCS signaling without VISM card involvement. In this
Note
configuration, a CCS channel is connected directly to the call agent that handles all necessary
processing of signaling information.
Figure 3-2
VoIP switching/trunking,
T1/E1
Signaling
CAS signaling can be configured, in the switched AAL2 PVC operating mode, to send the signaling to
the call agent or over an AAL2 PVC as in the AAL2 application.

CAS Processing in VoIP Switching and Switched AAL2 PVC Operating Mode

In the VoIP switching and switched AAL2 operating modes, CAS signaling is processed by the call agent
using SGCP.
The call agent performs the following functions:
•
•
The VISM card performs the following functions:
•
•
•
Cisco VISM Installation and Configuration Guide
3-6
VISM Signaling Paths
CCS (Q.931 using RUDP/UDP/IP)
Type?
AAL1/AAL2 SVC
TDM Grooming
Switched
Mode?
AAL2 Trunking
Type?
Issues the SGCP Notification Request command to instruct VISM which CAS signals are to be
reported to the call agent.
Instructs VISM which CAS signals to send out the DS0.
Responds by sending acknowledge messages in return to call agent commands.
Sends received CAS signals back to the call agent by using the SGCP Notify command.
Interfaces with the DSP drivers, which perform the detection and generation of CAS signals.
CAS (xGCP)
CAS (xGCP)
Type?
AAL2
CAS (trunk)
CAS (AAL2 Type 3)
CCS (AAL5 PVC)
Chapter 3 VISM Functional Description
To Call Agent
CCS (AAL5 PVC)
To ATM
Trunks
Release 3.0, Part Number OL-2521-01 Rev. D0, June 2004