User's Manual 368 Document #: LTRT-10466
Mediant 500L MSBR
To enable QSIG tunneling:
1. In the Digital Gateway Parameters page (Configuration tab > VoIP menu > GW and
IP to IP > Digital Gateway > Digital Gateway Parameters), set the 'Enable QSIG
Tunneling' parameter (EnableQSIGTunneling) to Enable on the originating and
terminating devices.
2. Configure the QSIGTunnelingMode parameter for defining the format of encapsulated
QSIG message data in the SIP message MIME body (0 for ASCII presentation; 1 for
binary encoding).
3. Set the ISDNDuplicateQ931BuffMode parameter to 128 to duplicate all messages.
4. Set the ISDNInCallsBehavior parameter to 4096.
5. Set the ISDNRxOverlap parameter to 0 for tunneling of QSIG overlap-dialed digits
(see below for description).
The configuration of the ISDNInCallsBehavior and ISDNRxOverlap parameters allows
tunneling of QSIG overlap-dialed digits (Tel to IP). In this configuration, the device delays
the sending of the QSIG Setup Ack message upon receipt of the QSIG Setup message.
Instead, the device sends the Setup Ack message to QSIG only when it receives the SIP
INFO message with Setup Ack encapsulated in its MIME body. The PBX sends QSIG
Information messages (to complete the Called Party Number) only after it receives the
Setup Ack. The device relays these Information messages encapsulated in SIP INFO
messages to the remote party.
24.6 ISDN Overlap Dialing
Overlap dialing is a dialing scheme used by several ISDN variants to send and/or receive
called number digits one after the other (or several at a time). This is in contrast to en-bloc
dialing in which a complete number is sent in one message.
The device supports the following ISDN overlap dialing methods:
Collects ISDN called party number digits and then sends the SIP INVITE to the IP side
with the complete destination number (see ''Collecting ISDN Digits and Sending
Complete Number in SIP'' on page
368)
Interworks ISDN overlap dialing with SIP, according to RFC 3578 (see ''Interworking
ISDN Overlap Dialing with SIP According to RFC 3578'' on page
369)
Note: ISDN overlap dialing is applicable to BRI.
24.6.1 Collecting ISDN Digits and Sending Complete Number in SIP
The device can support an overlap dialing mode whereby the device collects the called
party number digits from ISDN Q.931 Information messages or DTMF signals, and then
sends a SIP INVITE message to the IP side containing the complete destination number.
ISDN overlap dialing for incoming ISDN calls can be configured for the entire device or per
ISDN trunk. This is configured using the global, ISDNRxOverlap parameter or the
ISDNRxOverlap_x parameter (where x denotes the trunk number), respectively.
By default (see the ISDNINCallsBehavior parameter), the device plays a dial tone to the
ISDN user side when it receives an empty called number from the ISDN. In this scenario,
the device includes the Progress Indicator in the SetupAck ISDN message that it sends to
the ISDN side.
The device can also mute in-band DTMF detection until it receives the complete
destination number from the ISDN. This is configured using the MuteDTMFInOverlap
To Next Page
Loading...
