IP/VoIP Protocol Simulators

Core Network Simulators

MAPS™ CAS Protocol Emulator

(Channel Associated Signaling (CAS) Emulation)

MAPS™ CAS Protocol Emulator Software Ver 12.9.19  | Download Now!

Background

Signaling that occurs between switches (such as PBXs, local exchange carrier and interexchange carrier) in telephone networks is sent either within the voice traffic or on a separate dedicated signaling channel. Channel Associated Signaling (CAS) is a method of signaling where a channel or timeslot carrying speech also carries with it the signaling and addressing to set up and tear down calls. This supervisory signaling carried as "on-hook" and "off-hook". The addressing is carried as DTMF (Dual Tone Multi Frequency) or as MF (Multi Frequency). This form of signaling is still used to route calls on the public switched telephone network (PSTN) including subscriber lines like 2wire local loops, on trunks between central offices (CO), and on access trunks such as PBXs. Typical CAS signaling methods are: Loop Start, R1, MFC-R2, SS5, Sweden P7, FGD, SF Signaling, Voice Call and other variants of these methods.

In the T1 world, CAS protocols are implemented through "robbed bit signaling", a unique way of signaling that has always caused confusion among engineers. In the E1 world, CAS protocols are implemented through time-shared use of timeslot 16. In both systems, dual tones representing digits are used for ANI and DID identifiers.

Overview

CAS emulation is added to GL's Message Automation and Protocol Simulation (MAPS™) platform. MAPS™ is a protocol simulation and conformance test tool that supports a variety of protocols such as SIP, MEGACO, MGCP, SS7, ISDN, GSM, MAP, CAS, LTE, UMTS, SS7 SIGTRAN, ISDN SIGTRAN, SIP I, GSM AoIP, Diameter and many others.

MAPS™ CAS Emulator is a client-side application that works along with GL’s T1/E1 Analyzer Cards and Windows Client/Server software. This test tool is used to perform testing using CAS signaling and transmission and detection of TDM traffic over T1/E1 using scripts, and offers a complete solution for testing, troubleshooting, and maintenance of devices and networks implementing CAS. MAPS™ CAS automates the testing procedure with ready scripts for inbound and outbound calls. Calls are established, once the signaling information such as signaling bits, DTMF/MF digits, or Tones are sent or detected.

MAPS™ CAS is widely used for following test solutions-

  • High density FXO Simulation - supports up to 96 Analog Channels
    (using MAPS™ CAS and Channel Bank)
  • Testing Hybrid networks - using MAPS™ CAS and MAPS™ SIP/MGCP
    (using MAPS™ CAS, Channel Bank, and MAPS™ SIP/MGCP)

GL’s MAPS™ CAS Emulator requires additional licenses:

  • XX610 - Client Server w/Tx-Rx File
  • XX620 - Client Server w/Dtmf
  • XX630 - Client Server w/Dsp
  • Channel Bank (APSCB-24 or APSCB-48) for 2wire emulation
  • XXXFT0 - Fax emulation option

MAPS™ CAS Emulator supports typical CAS signaling methods including Loop Start, R1, MFC-R2, SS5, Sweden P7, FGD, and other variants of these methods. MAPS™ CAS also supports simulation of SF, Voice Call and SS5 Signaling using VF Input/Output interfaces available on tProbe hardware unit.MAPS™ CAS includes powerful utilities like Profile Editor and Script Editor which allow new scenarios to be created or existing scenarios to be modified for CAS Signaling. The test configuration window allows users to configure various CAS signaling types (Loop Start, R1, MFC-R2, SS5, Sweden P7, FGD, SF Signaling, Voice Call) including R1 digit parameters, flow control parameters, forward/ backward tone parameters and various others to transmit and receive CAS inbound and outbound signals.

MAPS™ CAS supports simulation of CAMA trunks connected to the 911 selective router (SR). CAMA type signaling trunks are used to provide the calling party’s Automatic Number Identification (ANI) to the selective router. The selective router then routes the call to the appropriate Public Safety Answering Point (PSAP) based on the calling party’s location. Both analog and digital (T1) CAMA simulations are supported. Analog simulation requires an additional channel bank specially configured for CAMA.

MAPS™ application supports a Command Line Interface (CLI) such as the Java, VBScripts, TCL, Python scripting tools, to provide the capability of remote operation, automation, and multi-site connectivity.

With the purchase of additional licenses (xx610, xx620, xxFT0) traffic can be simulated over T1/E1 interfaces. Supported traffic includes transmission and detection of TDM digits, voice files, single tone, dual tone, speech and FAX. Also supports various traffic events simulation during the course of a call.

Features

Call Scenarios

  • Caller ID
  • Two-way Calling
  • Three-way Calling
  • Three-way Calling with Calling Party Number Identification
  • VMWI – Voice Mail with MWI (message waiting indicator) and SDT (stutter dialtone)
  • Call Waiting – Detect tone, call id, flash to accept call

Protocols

  • T1 Wink Start (R1 wink)
  • T1 Loop Start and T1 Ground Start
  • T1 Feature Group D (FGD)
  • T1 Immediate Start
  • T1 CAMA (Centralized Automated Message Accounting)
  • T1 SF Signaling
  • T1 Voice Call Signaling
  • T1/E1 SS5 Signaling
  • E1 MFC-R2 (All variants, full /semi compelled)
  • E1 European Digital CAS (EUC)
  • E1 Digital E & M
  • E1 International Wink Start
  • E1 Sweden P7
  • Any User-Defined CAS Protocol

Functionalities

  • Voice Prompt Confirmation (requires VQT)
  • Voice Quality and Delay Measurements (requires VQT)
  • Detect Caller ID, and VMWI
  • Basic telephony functions - On-hook, Off-hook, Detect ringing signal, Dial, and 3-Way Call (using flash hook)
  • Both analog and digital (T1) CAMA simulation is supported
  • Dial Tone Delay, Post Pickup Delay, special dial tone, stutter dial tone, special information tone, call waiting, call in progress tone, reorder tone, busy tone, congestion tone, confirmation tone, howler tone, and ring-back tone
  • Fax - Send /Receive fax image (TIFF format) file from/to the specified location.
  • Call Failure events
  • Call Completion events
  • Call Drop (sustain calls) events

Solutions

CLI Capabilities

  • TCP/IP based Client Server application
  • API available for Tcl, Python, VBScripts, Java

Reporting

  • Central Database of events/results/errors
  • Multi-User, Multi-Test, Multi-Reporting
  • Executed test cases
  • Successful test cases
  • Failed test cases
  • Failed reason
  • Test results showing voice quality, failed call attempts, dropped calls
  • PDF and CSV file formats

Solutions

Solution 1: High Density FXO Simulation with MAPS™ CAS and Channel Bank

MAPS™ CAS Server connected to Third-party Channel Banks
Features High Density NB Solution
MAPS™ CAS
Space Considerations 1U (MAPS™ CAS)
3U (Channel Bank)
Ports Quad T1 (4 x T1)
96 Analog Channels
FXO Audio NB Support
Operation Fully Independent Ports with control b/w systems
Bulk Call Yes – Supports
Solution 2: End-to-end Hybrid Network Testing using High Density MAPS™ CAS and Channel Bank

Features Hybrid Network Test Solution
MAPS™ CAS
Space Considerations 1U (MAPS™ CAS)
1U (MAPS™ SIP/ MAPS™ MGCP)
1U (Audio Codes Media Gateway)
3U (Channel Bank)
Ports Quad T1 (4 x T1)
96 Analog Channels
FXO Audio NB Support
Operation Fully Independent Ports with control b/w systems
Bulk Call Yes – Supports

Supported Protocols Standards

MAPS™ CAS Simulator supports the following CAS protocols:

  • E1 MFC-R2 Signaling  - Defined by the ITU Recommendations Q.421-Q.442, uses a multi-frequency compelled signaling protocol to exchange address information. Sends MFC-R2 forward and backward tones per CCITT specifications. MAPS CAS includes ready profiles for India, China, Mexico and different country specific implementations will be supported in future.
  • E1 European Digital CAS (EUC)
  • E1 Digital E & M
  • E1 International Wink Start
  • E1 Sweden P7
  • T1 Wink Start (R1 wink) - The R1 wink protocol uses one-bit signaling, and the wink (brief presence of current or variation of the signaling bit) that the inbound side uses to indicate readiness to receive address signaling
  • T1 Loop Start
  • T1 Ground Start
  • T1 Feature Group D
  • T1 Immediate Start
  • T1 FXO CAMA (Centralized Automated Message Accounting)
  • T1 SF Signaling
  • T1 Voice Call Signaling
  • T1/E1 SS5 Signaling
  • Any User-Defined CAS Protocol

E1 MFC-R2 Call Simulation

The following table describes the line signaling for a typical call:

State Outbound
(AfBfCfDf)
Direction Inbound
(AbBbCbDb)
Idle 1001
(Idle)
  -------
  <-------
1001
(Idle)
Seizure 0001
(State=INIT)
  -------> Seizure Detected
Incoming Call
Seizure acknowledged     <------- 1101
State=Idle
       

The outbound sends the address information using in-band compelled MF tones. The inbound completes the compelled sequence by accepting or rejecting the call, using the last backward compelled tone. If the call is accepted, the inbound plays a ring tone on the line, and then signals answer call by setting the Ab bit to 0.

Ringing

 

 

<-------

Send ring back tone
State=Idle

Answer - conversation state

 

(State=Outbound Initiated)
Call connected

<-------

0101
(State=INIT A=0101)
Answering call
Call-Connected

       

Depending on which side hangs up the call first, a clear back signal or a clear forward signal is generated. Depending on national specifications, there might be a period of time in which the inbound side holds a release guard state, which is the same as clear back but happens when the outbound side is already in the idle state. Idle follows.

Inbound hangs up first: Clear back

 

 <-------

1100
(Call-Released)

Clear forward

1001(call Released)
State=Connected Outbound

------->

 

Idle

1001

------->
 <-------

1001

Outbound hangs up first: Clear back

1001
(Call-Released)

------->
 

 

Release guard

 

 <-------

1100(call Released)
State=Connected Inbound

Idle

1001

------->
  <-------

1001


MAPS™ CAS MFC-R2 can place and answer call on the selected timeslot and Send or Receive Traffic. The ready scripts used can detect events and respond with appropriate actions with respect to the states. The Events encountered during the progress of the calls are logged as seen in the screen below.

CAS MFCR2 Place and Answer Scripts

Screenshot of MFCR2 Call Events Log

FGD Call Simulation

The following table describes the line signaling for a typical call:

State Outbound AfBf Direction Inbound AbBb
Idle 0 0 <---------------> 0 0
Seizure 1 1 --------------->  
Seizure acknowledged   <--------------- 1 1 – 0 0 (Wink)

The outbound side starts to send the address information using MF tones. Feature group D can transfer more than one digit field to speed up long distance calls. Every field starts with a KP tone (start of pulsing) and ends with ST tone (end of pulsing). After each digits field the inbound side acknowledges the reception with a signaling bit wink.

Register signaling first field digit spill MF tones Start
KP
--------------->  
  Called Number --------------->  
  MF tones End
ST
--------------->  
  MF tones Start
KP
--------------->  
  Calling Number --------------->  
  MF tones End
ST
--------------->  
Acknowledgment of Digits Reception   <--------------- 1 1 – 0 0 (Wink)
Once all the address information has been transferred, the inbound side accepts the call by sending the off-hook signaling code or rejects the call sending Idle signaling code
If the call is rejected, the outbound side switches back to signaling AB = 00 (idle), clearing the line.
Clear forward 0 0 <---------------> 0 0
If the call is accepted, the inbound side answers the call by flipping both backward bits to 1.
Answer   <--------------- 1 1
Call Active - Conversation State
Clear 0 0 <---------------> 0 0
Idle 0 0 <---------------> 0 0


MAPS™ CAS FGD can place and answer call on the selected timeslot and Send or Receive Traffic. The ready scripts used can detect events and respond with appropriate actions with respect to the states. The Events encountered during the progress of the calls are logged as seen in the screen below.

FGD Place and Answer Scripts

Screenshot of FGD Call Events Log

T1 Wink Start (R1 wink) Call Simulation

Call Generation feature allows the user to simulate incoming and outgoing communications in CAS network, where signaling transitions occurs between switches, using proper scripts and profiles. The profile allows necessary parameters of call controls to be changed during runtime.

The following depicts the typical CAS signaling procedure for Loop Start lines -


Side A to Side B CAS Call Flow

The screenshot below shows MAPS™ acting as outbound terminal and transmitting the signaling bits to the other switch MAPS™ provides Event Log, Error Events, and Captured Errors report log encountered during the progress of the call.

CAS CIDCW – Call ID Call Waiting Script

Screenshot of CIDCW Call Events Log

European Sweden P7 Call Simulation

The following table describes the line signaling for a typical call:

CAS Signaling PABX (tProbe™) to Multiplexer (Subscriber)

Signal or state ASB 501
a | b | c | d
Multiplexer
a | b | c | d
Idle 1  0  0  1 1  0  0  1
Seizure (Ringing) 1  0  0  1       Line
0  1  0  1       Signal
--------------->
1  0  0  1
Answer (Off Hook)                     Line
0  1  0  1       Signal
<---------------
1  0  0  1
0  0  0  1
Stop ringing 0  1  0  1       Line
0  0  0  1       Signal
--------------->
0  0  0  1
Register recall                     Line
0  0  0  1       Signal
<---------------
0  0  0  1
1  0  0  1
0  0  0  1
Clear backward                     tone
1  0  0  1       Signal
                       >>>>>>>
X  0  0  1
On Hook (clear forward)                     Line
1  0  0  1       Signal
<---------------
0  0  0  1
1  0  0  1


MAPS™ CAS SwedenP7 can place and answer call on the selected timeslot and Send or Receive Traffic. The ready scripts used can detect events and respond with appropriate actions with respect to the states. The Events encountered during the progress of the calls are logged as seen in the screen below.

SwedenP7 Place and Answer Scripts

Screenshot of SwedenP7 Call Events Log

CAMA Signalling Simulation for 911 Systems

CAMA is a special analog trunk originally developed for long-distance billing but is now mainly used for emergency call services: 911 and Enhanced 9-1-1 (E-911). CAMA trunk connects a customer switch directly to the selective router (SR) in the service provider network.

GL’s MAPS™ CAS Emulator can be used to simulate CAMA trunks connected to the 911 selective router (SR). CAMA type signaling trunks are used to provide the calling party’s Automatic Number Identification (ANI) to the selective router. The selective router then routes the call to the appropriate Public Safety Answering Point (PSAP) based on the calling party’s location.

Both analog and digital (T1) CAMA simulations are supported. Analog simulation requires an additional channel bank specially configured for CAMA.

The below figure illustrates a typical FXO CAMA signaling scenario where MAPS™ CAS simulates the CAMA trunk connected to the 911 selective router.


Digital CAMA Simulation

Analog CAMA Simulation

CAMA circuits connected to the E-9-1-1

CAMA type signaling is used for provisioning the calling party’s Automatic Number Identification (ANI) to the 911 selective router.
The ANI in the form of MF digits can be defined as: KP-I-NXX-XXXX-ST, where,

KP - indicates a KP (Key Pulse) signal
I - information digit
NXX - the prefix of the telephone number (exchange)
XXXX - the caller’s PBX station number
ST - indicates a ST (Start Pulse)

The figure below outlines the signaling sequence for CAMA type trunks connected to the 9-1-1 switch:


Signaling sequence for CAMA type trunks connected to E-911 switch

CAMA trunks connected to PSAP

For an alternative configuration in Private Exchange Branches (PBX) where the CAMA trunks are connected directly to the PSAP, the ANI is defined as: KP-NPD-NXX-XXXX-ST where,

KP - indicates a KP (key pulse) signal
NPD - numbering plan digit representing the area code of the PBX caller who originated the 9-1-1 call
NXX - the prefix of the telephone number (exchange)
XXXX - the caller’s PBX station number
ST - indicates a SP (Start Pulse)

The figure below outlines the signaling sequence for CAMA type trunks connected directly to the PSAP:

MAPS™ CAS Emulator application displaying a real-time signaling sequence of the CAMA type trunk connected to the 911 selective router.


Signaling sequence for CAMA type trunks connected to the PSAP

MAPS™ CAS simulating CAMA trunks

Single Frequency (SF) Signaling

In analog circuits, channel bandwidth is divided into a 300 – 3400 Hz “voiceband” used for speech and/or data, and a “supervisory band” centered at 2400/2600/2800 Hz used for the signaling tone.  Because both the supervisory signal (SF Tone on Idle and Active modes) and line traffic are carried in the same channel, filters are normally required at each end of the connection to separate out the line signal from the voiceband traffic. 

MAPS™ CAS Single Frequency (SF) simulator can generate signalling tone on Idle and Active Modes with configurable operational frequency (2400/2600/2800 Hz) bands for analog G/G interface. It also has efficient filters to extract Voice from line signals and filters to inform the state of the remote-end efficiently.

Other related features include -

  • Selection to SF signalling on Idle and Active mode operation
  • User configurable Signalling Tone
  • User control on call to Terminate, Answer, Reject calls
  • Extracted voice can be recorded
  • Ladder diagram for call flows
  • Events window to keep track of the call status

The following are the examples of Call Supervision in SF Tone on Active Mode and Idle Mode:

  • The caller’s DTMF digits is superimposed on the signaling tone as it is inserted when seizing the channel.


  • The calling side seizes the line by dropping the signaling tone (Line seizure state). At this point, addressing tones are exchanged according to the signaling standard. 

The following call flows illustrate the SF Signaling procedure in Active Mode using MAPS™ CAS

SF Signaling Place Call Message Sequence
(ACTIVE Mode)
SF Signaling Answer Call Message Sequence
(ACTIVE Mode)

MAPS™ CAS SF Signaling can place and answer call (in both Active mode and Idle modes)on the selected timeslot and Send or Receive Traffic over established call.

SF Signaling Place Call Simulation
(ACTIVE Mode)
SF Signaling Answer Call Simulation
(ACTIVE Mode)
   
SF Signaling Place Call Simulation
(IDLE Mode)
SF Signaling Answer Call Simulation
(IDLE Mode)

Voice Call Signaling

Voice call lines are typically used for four-wire, point-to-point, two-way voice calls.  A Voice detect (VOX) circuit is used on the receive pair to detect incoming audio and signal the voice switch.  No signaling is used on the transmit pair. These calls are sometimes configured on 2w circuits.

MAPS™ CAS supports Voice Call Signaling by providing voice activated circuitry (VOX) to control voice connectivity and ensure immediate activation of the circuit upon receipt of incoming voice. During out-going call, it seizes (open) any circuit designated by the Government as a voice call line and transmits the voice into the circuit, whenever the circuit is activated.

User configurable VOX threshold, exhibit a voice signaling threshold of -26 dBm0 (nominal test level) and blocks responses to voice signals below the threshold of -26 dBm0 for the analog G/G interface. The ready scripts used can detect events and respond with appropriate actions with respect to the states.

The following depicts the typical Voice Call Signaling procedure simulation using MAPS™ CAS

Voice Call Signaling Message Sequence Voice Call Recording

SS5 / ATS No.5 Signalling

MAPS™ CAS supports Signalling System No 5 Line and register signalling procedure simulation as per Q.140- Q.199. SS5 specifications. SS5/ATS-No.5 call simulation is automated with ready-to-use scripts and facilitates to add events on active calls.
ATS-No.5 is a variant of SS5 signalling system, which is used in order to Seize a line, clear a line from either calling or called user side, block a line and answer a call. Line signals use one or two tones. VCSs are able to distinguish between different line signals by keeping track of the call state during the call setup or clearing procedure. Line signals can be sent from either side of an inter-VCS link. ATS-No.5-line signals are compelled implying that each line signal sent in one direction has a corresponding acknowledgement line signal in the opposite direction.

The following call flows illustrate the SS5 Signaling procedure.

CAS SS5 Signaling Place Call CAS SS5 Signaling Answer Call

MAPS™ CAS SS5 Signaling can place and answer call on the selected timeslot and Send or Receive Traffic as shown in the below screenshots.

SS5 Signaling Place Call SS5 Signaling Answer Call

Screenshots

Testbed Setup Configuration

Load Generation Parameters

Script Editor

Profile Editor

Script Contents and Script Flow

Call Statistics

MFCR2 Call Events Log

FGD Call Events Log

SWEDENP7 Call Events Log

SF Signaling Call Events Log

Voice Call Signaling Call Events Log

SS5 Signaling Call Events Log

Buyer's Guide

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 ETA or EEA (Octal/Quad Boards), PTA or PEA (tProbe Units), UTA or UEA (USB Units), HUT or HUE (Universal Cards), and HDT or HDE (HD cards) depending upon the hardware.

Item No. MAPS™ for TDM Network
(requires T1 or E1 Hardware and Basic Software)
XX651 MAPS™ CAS Protocol Emulator
MAPS™ APS Protocol Emulator
XX610 Transmit and Receive File Capability
XX620 Client Server Transmit/Detect digits (Place Call/ Answer Call)
XX630 Client Server DSP operations
  Related Software
XX625 T1 or E1 CAS Simulator (Client-Server Based) *
* Requires XX610, XX620, XX630
DR010
DR001
DCOSS CAS Simulator (Loop Start & Ground Start)
DCOSS Software (**Required**)
XX031 Enhanced T1 / E1 Call Capture/Analysis Software
XX647 MAPS™ ISUP Conformance Test Suite (Test Scripts)
XX648 MAPS™ ISDN Emulator
XX649 MAPS™ ISUP Emulator
XX652 MAPS™ MC-MLPPP Emulator
PKS120

PKS121

PKS122

PKS123

PKS124

PKS130
MAPS™ SIP Emulator

MAPS™ SIP Conformance Test Suite (Test Scripts)

MAPS™ MEGACO Emulator

MAPS™ MEGACO Conformance Test Suite (Test Scripts)

MAPS™ MGCP Protocol Emulation with Conformance Test Suite

MAPS™ SIGTRAN Emulator
  Related Hardware
FTE001

ETE001
QuadXpress T1E1 Main Board (Quad Port– requires additional licenses)

OctalXpress T1E1 Main Board plus Daughter Board (Octal Port– requires additional licenses)
PTE001 tProbe™ Dual T1 E1 Laptop Analyzer with Basic Analyzer Software
HTE001 Universal T1/E1 Card with Basic Analyzer Software
UTE001 Portable USB based Dual T1 or E1 Laptop Analyzer with Basic Analyzer Software