Call Capture and Analysis
The Call Capture and Analysis (CCA) application is used to initiate recording of calls, either automatically or manually directly
from T1/E1 and/or 2-wire lines. The application uses GL's USB Portable T1/E1 Analyzer Units or Universal HD T1/E1 Analyzer
Cards to interface non-intrusively with T1 or E1 lines.
Automatic call capturing can be triggered from both directions (east and west) of transmission.
The call capture application supports following types of triggers for auto capturing of call
- Signaling based triggers - CAS -R1, wink start, MFC-R2
- ISDN and SS7 message based triggers
- Traffic activated triggers
- Voice based on a minimum power level
- Tones of specified frequency - Ring back tone, Dial tone, Busy tone, and DTMF digits
- Fax traffic - V.32 / V.17, V.27, V.29,
- Modem traffic - V.22 forward/reverse channel, V.34 & V.90 uplink, Binary V.90 downlink, FSK
- Any type of signal based on any power level
Subsequently, captured calls can be played back and analyzed in time and spectral modes
using a commercial sound card, built-in high fidelity speakers, and audio viewing software (Adobe Audition, Goldwave).
Frequency, power of east and west directions cannot be shown in real time in CCA application. We can only capture the files. The
application also indicates the channels on which a recording is taking place and the files names to which data is being stored. Scanning
mode is possible wherein all 24 or 30 channels are scanned for call initiation and recording. A message area provides status of the
capture process. Other features include,
- Automatic or manual initiation of call recording
- Real-time display of signaling bits for all channels in both directions
- 'Scan' or 'Channel' mode for call initiation detection and capture
- User specified record time
- Automatic termination of recording, or Manual termination
- PCM data captured to two synchronized disk files (east and west directions) for post processing
- All call data are captured including signaling bits, voiceband data, signaling protocol data (e.g. DTMF or MF digits), various types of
traffic such as fax, modem, voice, and any type of signal.
- Unlike the other traffic options, triggering on voice traffic can be fine-tuned to the power level of the voice data.
- Voice power level can be set to filter out weak or undesirable voice data.
- ISDN calls recorded with CRV, ISDN message type, channel, direction, called and calling numbers. ISDN calls can be captured with
customized called and calling number filter.
- Enhanced application includes call capture based on SS7 signaling messages, and the ability to set triggering to capture calls
when any SS7 signaling messages are received.
- "Call filtering" feature is used to capture calls with a user-defined called and calling numbers rather than all calls.
- Various File naming conventions based on the type of capture. The file naming conventions suit various types of capture
applications such as MFC-R2, signaling, ISDN capture, manual capture etc.
- Different Encoding formats supported, including automatic conversion of u-law and A-law PCM files to WAV file format if required
- The digit parsing feature of CCA application helps user to distinguish CAS R1 or MFC-R2 calls by prefixing called or calling numbers
to the filename.
- Capability of capturing on a single direction, East or West side in a dual card system.
- Supports logging of call summary records, facility alarms, and supervisory signals in CSV or binary file formats.
- Provides an option of stamping the captured files sequentially or with date/time.
Automatic Call triggering can be done in one of the following ways:
- A,B,C,D - Signaling Bits- with user-defined start and stop ABCD signaling bits to initiate and terminate recording of files on chosen
timeslots - useful for CAS calls. In addition, CAS signaling such as DTMF digits, MF digits, and MFC-R2 digits conveying "called and calling
numbers" are decoded and attached as part of the captured file name.
- Tone - user-defined mono or dual tones can trigger the capturing of a call CCA - useful for fax calls
- Signaling + Tone - a combination of user-defined Start/Stop signaling bits followed by a mono or dual tone (user-defined) within a
specified timeout period - useful for capturing fax calls
- ISDN calls - capture gets triggered when any ISDN calls are placed. Called and calling number can be gathered as part of the
capture process and attached to the captured file name. During call capture, the following parameters are displayed: ISDN message
types, CRV, Time slot, card number, called and calling numbers.
- SS7 calls - SS7 voice calls are kept in CIC groups. When an SS7 call is detected, an Origination Point Code (OPC), a Destination
Point Code (DPC), and a CIC # is retrieved. If the comparison holds good capture task is performed, otherwise the call is discarded.
- Traffic activated - With this trigger option, it is possible to trigger on various kinds of traffic such as fax, modem, tones of standard
frequency, digits, voice, and any signal based on power level. Users can also define the traffic algorithms such as linear, quadratic, hybrid,
or hybrid filtered that performs the traffic classification.
Typical applications are:
- Call recording for post analysis
- Analysis of single/dual tones, DTMF and MF digit analysis (frequency, power, duration)
- Analysis of call quality (speech levels, noise levels, echo return loss, speech clipping, impulse noise, and other impairments)
- Call activity, call density, and call volume analysis
- Monitoring and recording Fax, Voice Modem, ISDN, SS7 and CAS calls
- Filtering of calls by "called" and "calling" number
- Listening to finished calls and active calls as they are occurring
- Remote monitoring of calls including remotely listening to calls
GL also provides other various transmission & capture software that helps is call monitoring & analysis over network.
Visit Call Signaling and Analysis page for more details.
Working with Call Capture and Analysis (CCA)
Display both CCA main menu image and this side by side
- Auto Scanning Capture Mode - Scans timeslots that were checked in "Timeslots" dialog box. The type of scanning that
occurs is dependent on the Capture Trigger Type selection.
- Manual Capture Mode - Permits capture manually, irrespective of signaling bits or tone definitions.
- Start Trigger Signaling bits - Signaling bits definition for the beginning of capture; must be a transition from the stop
trigger to the start trigger
- Stop Trigger Signaling bits - Signaling bit definition for the end of capture; transition not required
- Device Selection - Up to two devices may be selected for capturing or scanning.
- Record Time - In Auto Scanning mode, the duration of the capture can be limited to a certain length by checking Limited
Capture and setting the slider control
- Tone Wait - After a signaling trigger, the time (seconds) the application should wait for a defined tone to occur.
- CAS Digit Parsing - The CAS Digit Parser is used for CAS R1 protocol calls to name the call files using the digits that are
prefixed to the rest of the filename. By default, this option is disabled, during which, the files are named based on the timestamp and
timeslot information, such as Jun15E01_0002.pcm.
- File Naming Convention - Two different types of file naming conventions are provided based on the capture type for
signaling. The file naming conventions are:
Normal - This is the normal mode of capturing data that is prevalent common to both T1 and E1 analyzers.
MFC-R2 - If the CCA application captures data for MFC-R2 signaling type of calls, then this mode has to be enabled.
Selecting this option causes a change in the file naming extension. i.e. .pcm extension is removed”.
Call Playback and Viewing Features
Combined Oscilloscope (Time) and Spectral (Frequency) Views
Oscilloscope (Time Series) View
For a recorded call, a graph of the amplitude vs. time can be displayed. The display can be for either one side or both sides of the
call. Playback, zoom-in, zoom-out, and other options are available for analysis of partial and/or full call data/ Signaling data during call
set-up can be analyzed e.g. DTMF/MF, dial and busy tones at microsecond duration granularity. Every sample is recorded and
displayed.
There are several methods for viewing captured files supported by various visualization programs such as Adobe Audition and
Goldwave programs. Adobe Audition and Goldwave are used with a variety of file formats including PCM, wav, and others. Refer to
Adobe Audition and Goldwave User's Guide for detailed instructions or Contact GL Communications Inc for additional details or
clarifications about this.
Spectral View
A graph of power level vs. frequency is displayed for the user-selected portion of the recorded call. Users can set the frequency
resolution and frequency band of interest. The display can be either one side or both sides of the call. Useful for DTMF/MF, dial,
busy tone, speech and modem frequency analysis. Spectrogram displays are also possible.
Screen Shot of Spectral View
Goldwave
The wave graph of captured files can be visualized using this Goldwave software. The graphical software program should be
installed in order to directly invoke captured files through GL's T1E1 analyzer. Goldwave can be used to visualize maximum of two files.
Screen Shot of Wave Graph in Goldwave
To view stereo wave graph is displayed on selecting single captured files (with any extensions). Select dual files to view both
the graphs simultaneously. Goldwave is automatically called and the files are displayed in stereo mode.
Screen Shot of Stereo Wave Graph in Goldwave
The names of the files chosen for display is merged as one *.wav file. Goldwave uses variety of file formats including
*.pcm, A-Law, Mu-Law, *.wav, and others. Any file formats chosen is converted to *.wav while displaying graphs.
Example: For dual file graph display, select "Samp_wst.pcm" and "Samp_est.pcm", a single
"Samp_wst_ Samp_est.wav" file is created and the graph is displayed one below the other.
Tabular Analysis
A special DOS application is provided for MFC-R2 digit analysis (r2ana.exe). With this software captured files can be analyzed for
R2 tones and signaling. Forward and backward-paired tones are detected and displayed with time stamped indications of digit
durations and signaling changes. Call duration, timeslot, date, and time of occurrence are also recorded.
Call capture using WCS
GL's Windows Client/Server makes the T1/E1 Analyzer as server and allows performing of typical tasks such as real time recording
and transmission to/from files, dtmf/mf/mfcr2 digit detection and generation, bit error rate testing, alarm monitoring, Digital Signal
Processing (DSP) operations, ds0 power monitoring, and protocol decoding from multiple client locations.
GL's CAS simulator is a client-side application that works along with the GL's T1/E1 Analyzer. It can simulate and analyze any user
user-defined CAS protocols by providing signaling bit transitions and forward/backward frequency tones/digits. In addition to
generating/receiving CAS calls, the CAS simulator also processes the receipt of Dialed Number Identification Service (DNIS) and Automatic
Number Identification (ANI) information. Supported protocols include E1 MFCR2, T1 Winkstart, T1 Loopstart and Groundstart, E1
European Digital CAS, and any User-defined CAS.
Visit following webpages for more information
Additional Sample Screens:
ISDN Call Capture Options with NFAS (Non-Facility Associated Signaling)
The CCA gets triggered when any ISDN calls are placed. Capture occurs after the ISDN message, "SETUP", is detected
with the called/calling number that matches the filtering definition for ISDN Call Filtering Options.
CCA can be set to capture the ISDN calls on the trunks that contain D-Channel using options under NFAS. NFAS is a
standard option available for ISDN PRI call processing system. This allows a single D channel to control multiple PRI
trunks. With NFAS option, a single D-channel can control a maximum of 479 B-channels, i.e., up to 20 trunks (or a maximum of 478
with one B-channel as a backup). In case of GL's Dual T1/E1 Analyzer, a maximum of 95 B-Channels, i.e., up to 4 trunks is supported.
- Parameters
- NFAS D-Channel - Enables NFAS feature during ISDN call processing
- D-Chan # - This represents the trunk that contains the D-Channel or the signaling.
- Explicit Interface - This represents that the CCA is set to capture the calls on the trunks that does not
contain D-Channel or in other words, interface is set to capture on the trunks that use all 24 or 31 timeslots on T1/E1 respectively.
- Implicit Interface - This represents that the CCA is set to capture the calls on the trunks containing
D-Channel. For example, in the above illustration, Trunks 1 and 3 contain D-channels; to capture messages on these trunks,
CCA should be configured.
SS7 Call Capture Options
SS7 voice calls are kept in CIC groups. When an SS7 call is detected, an Origination Point Code (OPC), a Destination Point Code
(DPC), and a CIC # is retrieved. If the comparison holds good capture task is performed, otherwise the call is discarded.
- Data Rate: The possible data rates are 56 or 64 kbps.
- Call Filtering: SS7 Call Filtering is similar in functionality to that used in ISDN filtering. Regular expressions such
as "*", and "?" can be used. An expression such as "123*" means only call #'s that start with "123" have a possibility of being
captured.
- Signaling Selection: Incoming calls are detected on the signaling timeslot. Two sources of signaling can be
used, primary and secondary.
- CIC (Circuit Identification Codes) Group Configuration: SS7 voice calls are in CIC groups. When an SS7 call is
detected, an Origination Point Code (OPC), a Destination Point Code (DPC), and a CIC # is retrieved. For the first entry, there is a
starting CIC # of 2, with 9 CIC channels (Quantity), and a starting timeslot of 1. The starting CIC # of 2 is mapped to timeslot #1.
A CIC # of 10 is mapped to timeslot #9. All of the CIC #'s and timeslot #'s in the entry are contiguous.
Other Traffic Options
CCA also includes a feature to trigger capturing of calls based on various types of traffic such as fax, modem, voice, standard tones,
digits, and so on. They are V.22 bis forward channel, V.22 bis reverse channel, V.34 & V.90 uplink, V.29, V.32/V.17 > 2400 bps, V.27 ter @ 4800 bps,
V.27 ter @ 2400 bps, Voice, binary V.90 downlink, FSK, DTMF digits, Dial tone, Ringback, and Busy tone. Detecting the above types of traffic requires
use of the traffic classifier.
A 2048 byte (256 ms) block of data is sent to the traffic classifier. The traffic classifier determines if the data is one of the accepted types of traffic.
If the condition is met, then capture of the traffic data commences.
Unlike the other traffic options, triggering on voice traffic can be fine-tuned to the power level of the voice data. Setting the voice power level
can be used to filter out weak or undesirable voice data.
Note: CCA requires additional license for traffic activated triggering (XX031).
Screen Shot of CCA Traffic Options
There is also an option “Any Signal” to be defined in dBm. Selecting this feature bypasses the traffic classifier and detects the power level of the data.
If it exceeds the defined input data (e.g. -10dBm), then capture commences.
Screen Shot of "Any Signal" selection in Traffic Options
Stopping Traffic or “Any Signal” Capture
Setting the “Silence Options” slider allows for hang-ups during the capture of traffic or “Any Signal” data. For example, if DTMF traffic is being
captured, and then non DTMF data is detected, capture continues until the hang-up time limit set by “Silence Options” is exceeded. If the data reverts
back to DTMF, the capture continues as it was before the hang-up.
If the hang-up time limit is 400 milliseconds, only one hang-up is allowed before capture is terminated. Each buffer of data is of size 2048
bytes (256 ms).
Traffic Algorithm
The traffic classifier uses four different algorithms to choose from: Linear, Quadratic, Hybrid, or Hybrid Filtered.
- Linear – This algorithm is quicker to computer
- Quadratic – This gives better accuracy but need more time
- Hybrid (Recommended) – It is a combination of linear and quadratic, and the most reliable
- Hybrid Filtered – This eliminates misclassifications, for example, voice with many periods of silence.
The “Hybrid” is recommended algorithm and is used by default in the Multiple Call Capture.
CCA with other GL applications
Call Data Record (CDR)
The application works with CCA (Call Capture and Analysis) and VBA (Voice Band Analyzer) applications and
generates Call Summary and Call Detail reports. CDR provides comprehensive information on each and every call
occurring on T1 E1 lines, including voice capture, signaling information for CAS, ISDN, MFC-R2, SS7, all alarms and
errors occurring during the call, detailed voiceband event information (dual tones, fax tones, modem signals, and more),
detailed analysis of the voiceband call including noise level, speech level, speech activity factor, echo measurements,
and more. It also categorizes call as voice, fax, modem, or data.
For complete information on Call Data Record (CDR) application, click here.
Near Real-Time Voice Band Analyzer
The Near Real-time Voice-band Analyzer (VBA) is an analysis tool for monitoring voice band network traffic. The
VBA can host different analysis modules for monitoring speech and noise levels, line echo, and acoustic echo. VBA
operates in near-real-time, processing the signal files recorded by CCA. VBA records its output into two files, the
first containing overall channel measurements, and the second containing event records.
For complete information on Near Real-Time Voice Band Analyzer (VBA) application, click
here.
Call Management Utility
This application provides all the necessary management tools to perform function of recording voice calls. Call
records are immediately generated, indexed, and displayed once a voice recording over T1 or E1 lines is completed by
the CCA.
For more details, click here.
GLInsight™
The captured files can be analyzed using GL Insight™ Modem and Fax Analysis Software for 2-wire Analog
interface.
For more details, click here.
The capability of CCA software to non-intrusively record calls directly from T1/E1 lines offers a solution to capture Voice/ Fax / Modem traffic.
The 2-wire Analog Hardware Tap along with the GL’s T1/E1 Call Capture and Analysis (CCA) Software is used for capturing modem/fax data directly
from the 2-wire Analog interface. However, this capture solution requires the purchase of T1 / E1 Analyzer. The captured files can be analyzed using
GL Insight™ Modem and Fax Analysis Software for 2-wire Analog interface.
Using the 2-wire Phone Tap adaptor, one can non-intrusively ‘tap’ into the analog 2-wire line via the RJ11 interface
and then capture the bi-directional voice/fax/modem traffic with CCA.
This test is performed to
- Capture bi-directional traffic non-intrusively into a single PCM file
- Capture voice on 2-wire Analog interface
- All types of measurements associated with a 2-wire analog call
- Use with GL Insight™ for modem / fax data capture and analysis or Adobe Audition for analyzing / editing recorded files
Bridge and Monitor Connections
Buyer's Guide (for Ultra Card System):
Please Note: The XX in the Item No. refers to the hardware platform, listed at the bottom of the Buyer's Guide,
which the software will be running on.Therefore, XX can either be HDT, HDE, HUT, HUE, UTA or UEA depending upon the
hardware.
Back to Call & Signaling
Analysis Index Page
![](javascript:myOpen("images/callrec_spectralview.gif"))
![](javascript:myOpen("images/goldwave_image1.gif"))
![](javascript:myOpen("images/goldwave_image2.gif"))
![](javascript:myOpen("images/CCA_TrafficOptions.gif"))
![](javascript:myOpen("images/CCA_Traffic_AnySignal.gif"))
![Call Capture Analysis Main Menu](javascript:myOpen("images/main_menu.gif")){kind=link}
![Call Capture Analysis Configuration Tab](javascript:myOpen("images/main_menu_config.gif")){kind=link}
![Call Capture Analysis Timeslots Tab](javascript:myOpen("images/main_menu_timeslot.gif")){kind=link}
![Call Capture Analysis ISDN Options Tab](javascript:myOpen("images/main_menu_isdnoptions.gif")){kind=link}
![Call Capture Analysis SS7 Option Tab](javascript:myOpen("images/main_menu_ss7options.gif")){kind=link}
![Call Capture Analysis User Defined Tab](javascript:myOpen("images/main_menu_userdefined.gif")){kind=link}
![Call Capture Analysis Tone Detection Parameters Tab](javascript:myOpen("images/main_menu_tonedetection.gif")){kind=link}
![Call Capture Call Storage Options Tab](javascript:myOpen("images/main_menu_storage.gif")){kind=link}
![Time Series Display](javascript:myOpen("images/timeseries_piece.gif")){kind=link}
![Spectrum Display](javascript:myOpen("images/spectral_piece.gif")){kind=link}
![Monitor from a DSX-Patch Panel](javascript:myOpen("images/faq_figure3.gif")){kind=link}
![Bridge Mode Connections for Monitoring T1/E1 Signals for RJ-45](javascript:myOpen("images/faq_figure4.gif")){kind=link}
![Bridge Mode Connections Alternative Method](javascript:myOpen("images/faq_figure5.gif")){kind=link}
![RJ-45 Connections](javascript:myOpen("images/faq_figure7.gif")){kind=link}
