The QSLACs (quad subscriber line audio - processing circuit) on an AG 2000 board control:
The 2 wire impedance matching (factory set)
Frequency response and equalization (factory set)
Trans-hybrid balancing (variations are available)
Gain adjustments (-6 dB to +6 dB in 1 dB increments)
There are two QSLACs on an AG 2000 board. The first QSLAC services ports 0 - 3. The second QSLAC services ports 4 - 7. Each port can be configured separately. The configuration is contained in a QSLAC file. Each QSLAC file is customized for a specific line interface signaling module and for a certain country's two wire return loss requirements.
Through the Switching service, you can control the following on a per-port basis:
Transmit gain (-6 to +6 dB in 1 dB increments)
Receive gain (-6 to +6 dB in 1 dB increments)
|
Caution: |
Increasing gain may also increase noise, echo, and possibly cause oscillations on the telephone network. There also may be regulatory authority implications. Use gain with caution. |
Refer to Line gain configuration for more information on controlling the gain.
All QSLAC files have an extension of .slc and adhere to the following naming convention:
pp cty ss i.slc
|
Where... |
Represents the... |
For example... |
|---|---|---|
|
pp |
Two-character NMS product field. |
a2 = AG 2000 board |
|
cty |
Three-character ISO country code or region code. |
|
|
ss |
Two-character signaling type. |
ls = loop start dd = DID sl = subscriber loop |
|
i |
One character line impedance field. |
6 = short 600 Ohm lines 9 = short 900 Ohm lines n = lines longer than 2000 feet c = complex (used in some international markets) |
For example, a2usals6.slc represents the AG 2000 board/USA/loop start/ 600 Ohm line QSLAC file.
Natural Access configures the system for the QSLAC file that is intended for your country. Do not change the configuration unless you are confident that a change is required and is allowed by the regulatory agencies.
For more information about QSLAC files, refer to the NMS CAS for Natural Call Control Developer's Manual.
If the default file is not used, an entry is made in the error log file at boot time. If echo cancellation is enabled, there is no benefit in changing from the default QSLAC file.
For example, add the following statement to the board keyword file to load a QSLAC file:
NetworkInterface.Analog[0..7].ConfigFile = a2usals9.slc
Trunk control programs (TCPs) perform all the signaling tasks necessary to interface with the telephony protocol used on the line or trunk. TCPs are loaded onto an AG 2000 board at board initialization. After a TCP has been loaded to the AG 2000 board, the application must start up its protocol before it can use the TCP to perform call control on a specific port.
The following table lists the QSLAC files for loop start that can be selected for the United States and Canada:
|
File |
Description |
|---|---|
|
a2usals6.slc |
This is the default file that is used when you have a 600 Ohm PBX. |
|
a2usals9.slc |
Optimizes performance interfacing to a 900 Ohm PBX. |
|
a2usalsn.slc |
Optimizes performance interfacing to long lines (> 2000 feet). |
Other QSLAC files are used in other parts of the world. Natural Access configures the correct files for the countries that are supported.
For European countries that are not supported in the installation, use the a2eurlsc.slc file when connecting to the PSTN. Refer to the NetworkInterface.Analog[x].ConfigFile keyword for more information about QSLAC files. Refer to the NMS CAS for Natural Call Control Developer's Manual for information on changing network tone descriptions.
The following table lists the TCPs that are applicable to AG 2000 loop start boards:
|
Trunk control program |
Description |
|---|---|
|
nocc.tcp |
No call control. |
|
lps0.tcp |
Loop start on AG 2000. |
The following table lists the QSLAC files for subscriber loop that can be selected for the United States:
|
File |
Description |
|---|---|
|
a2usasl6.slc |
Default file used when you have a 600 Ohm telephone. |
|
a2usasl9.slc |
Optimizes performance interfacing to a 900 Ohm device. |
The following table lists the TCPs that are applicable to AG 2000 subscriber loop boards:
|
Trunk control program |
Description |
|---|---|
|
sta0.tcp |
Subscriber loop on AG 2000. |
|
nocc.tcp |
No call control. |
The following table lists the QSLAC files for DID that can be selected for the United States:
|
File |
Description |
|---|---|
|
a2usadd6.slc |
This is the default file that is used when you have a 600 Ohm trunk. |
|
a2usadd9.slc |
Optimizes performance interfacing to a 900 Ohm trunk. |
The following table lists the TCPs that are applicable to AG 2000 DID boards:
|
Trunk control program |
Description |
|---|---|
|
wnk0.tcp |
Inbound wink start protocol. |
|
nocc.tcp |
No call control. |