User`s guide

Dialogic
®
System Release 6.0 PCI for Windows
®
Release Update, Rev 62 — January 30, 2008 161
Dialogic Corporation
1.47 Support for QSIG NCAS Calls on Dialogic
®
DM3
Boards
With the Service Update, the ability to initiate Non-Call Associated Signaling (NCAS) calls
is supported for the QSIG protocol (E1 or T1) on Dialogic
®
DM3 Boards. The DM3 Boards
that support this feature are:
• Dialogic
®
DMV1200BTEP Media Boards
• Dialogic
®
DMV600BTEP Media Boards
• Dialogic
®
DMV960A-4T1 Media Boards
• Dialogic
®
DMV1200A-4E1 Media Boards
The feature is only supported on media loads that use the QSIG T1 or E1 protocol, for
example, ml2_qs2_qsige1.
NCAS can establish a virtual call within the network without actually associating the
B channel with the call. The call only exists on the D channel, which is normally used for
signaling. Once this virtual connection has been established, the customer premise
equipment (CPE) can send Facility messages to the switch or terminal equipment (TE) to
convey additional information. For example, Message Waiting Indicator (MWI)
supplementary service information can be encoded in a Facility IE and sent in a Q.931
Setup message. (The application is responsible for encoding/decoding the Facility IE.)
1.47.1 Feature Description
NCAS allows users to communicate by user-to-user signaling without setting up a circuit-
switched connection. This signaling does not occupy B channel bandwidth. A temporary
signaling connection is established (and cleared) in a manner similar to the control of a
circuit-switched connection.
Applications must use a specific channel for NCAS calls. For E1 interfaces, this is channel
30, that is, dtiBxT30. For T1 interfaces, this is channel 23, that is, dtiBxT23.
For outbound calls, when the call is set up with the Bearer Capabilities IE indicating that it
is an NCAS call, the call is sent out on the D channel, without an associated B channel.
Once the NCAS connection is established, the application can transmit user-to-user
messages using the call reference number (CRN) associated with the NCAS call.
For inbound calls, the Dialogic
®
Software provides the ability to detect if the incoming call
is an NCAS call or a standard circuit switched call by analyzing the information associated
with the GCEV_OFFERED event triggered by the incoming call.
With DM3 Boards, the Dialogic Software and firmware support 8 NCAS calls per span,
that is, 32 simultaneous NCAS calls per quad-span board. The 8 NCAS calls per span are
in addition to the normal calls that you can have. For example, with T1, you can have 23
calls per span (including one on dtiBxT23), plus 8 NCAS calls on dtiBxT23 at the same
time.