Codec Tieline Gateway, Руководство пользователя

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188 Gateway and Gateway 4 Manual v1.2
© Tieline Research Pty. Ltd. 2021
(without the country or area code) as the DN/MSN for a B channel, then only that
corresponding B channel will answer an incoming call to that number. Entering DN/MSN
numbers for each B channel allows the codec to ignore calls without matching DN/MSN
numbers. This is the best way to answer calls from codecs in a predictable manner.
SPID Numbers in North America
ISDN relies on an initialization procedure for associating Service Profiles with specific
terminating equipment (e.g. your audio codec) rather than lines. In the US Telcos assign
a Service Profile ID (SPID) number which assists in identifying different ISDN services
across the network. Your Telco must provide a SPID for each B channel you order when
connecting over US-Nat or US-AT&T networks in the US. A SPID is not required when
using the AT&T PTP protocol.
Typically, each ISDN BRI service in the US will have two SPIDs and these must be
entered correctly. When you enter a SPID into your codec and connect it to an ISDN line,
an initialization and identification process takes place, whereby the terminating equipment
(your codec) sends the SPID to the switch. The switch then associates the SPID with a
specific Service Profile and directory number.
Note: SPID numbers normally include the phone number and additional prefix or suffix
digits up to 20 digits long.
23.25.2 Configuring ISDN Answering
ISDN Answer Configs are used to determine how codec ISDN modules will behave when
answering ISDN calls.
The following image explains the difference between answering calls from Tieline codecs sending
session data, and non-Tieline codecs making sessionless ISDN calls. Codecs sending Tieline
Session Data contain all the information required to connect, e.g. algorithm and audio stream
routing settings. When answering sessionless calls it is necessary to configure the answering
codec with an
ISDN Answer Config , which tells the answering codec how a sessionless call will
try and connect.
It is possible to save up to two different ISDN Answer Configs , which allows 2 ISDN B channels to
be individually configured for unique answering behaviors. ISDN answering can be configured to suit:
· Hardware available in the codec, i.e. the number of B channels available.