TDM SDK FAQ

Q. Can Sangoma TDM SDK sends response/data when any data/event is received?

Ans. Sangoma TDM SDK(Analog/PRI/ISUP) is Tapping only i.e. it only receives data from the network. User has full access to BCHAN(voice), and can use existing libsangoma RX functions within the Sangoma TDM SDK.

Q. Is the Sangoma TDM SDK Thread safe. How to call a thread for each Sangoma port to handle events independently?

Ans. Yes, Sangoma TDM SDK is thread safe. We recomended to run a thread per call.

Q. What are advantages of Sangoma TDM SDK over LibSangoma voice API? Is it better in terms of structure, stability, performance?

Ans. Sangoma TDK SDK is a superset of libsangoma. It is build on top of libsangoma to provide a unified signaling and media SDK.
        Sangoma TDM SDK provides:

1. Programmable configuration.

2. Integrated protocol stacks, optimized for Tapping.

3. Unified signalling API for multiple protocols
   
   

   • PRI, SS7, MTP2, Analog.

4. Fully working sample code that user can use to rapidly prototype their application.

        Libsangoma provides:

1. Raw access DCHAN & BCHAN interfaces.

2. Base functions to perform programmatic configuration, statistics and operation of Sangoma boards.

3. It does not provide any signalling such as: PRI,SS7.

   • It is user responsibility to handle signalling.

       SANGOMA TDM SDK Architecture:

• Sample code for PRI, SS7, Analog, MTP2

• SDK commin tapping config, statistic, operation library

• FreeTDM

• Libsangoma

        For further Detailed explanation please visit Link : TDM SDK

Q. How to change the wanpipe/port configuration?

Ans. Default wanpipe configuration w.r.t. pri/ss7/mtp2/analog etc. is done by "sangoma_set_default_<tapping_type>()" function present in libsangoma_wp_config.c file loacted at "sangoma-tdm-sdk-<verison>/applications/common/" path.
        E.g. wanpipe for PRI tapping is being configured at "sangoma_set_default_pri_tap_config()" function. Any changes w.r.t. wanpipe configuration for PRI tapping needs to be change in this function for PRI tapping and similarily for others.

For detailed Tapping configuration please go through the given link: TDM SDK Configuration

Q. How to change number of ports that needs to be configured?

Ans. In sample tapping application number of ports that need to be configured is hard-coded. Customer can change number of ports or which port that needs to be  configured and started changing "port_id" as define in "sample_app_hwprobe_calback()" function present at sample application of different tapping application types.
         E.g. In order to changes "port_id" w.r.t. PRI Tapping just search for string "port_id" in "sample_app_hwprobe_calback()" function present in "sample_application.c" file located at "sangoma-tdm-sdk-<verison>/applications/sample_isdn_tapping/".

Q. What to do in case wanpipe is not in connected state?

Ans. If wanpipe is not getting in connected first thing to do is debug wanpipe using below link:
         Wanpipe Debugging
After debugging wanpipe if everything looks good then please change the framing type in the wanpipe configuration. For change in wanpipe configuration please go above explanation w.r.t. change in wanpipe configuration. In case after changing the framing type still wanpipe is not in connected state and everything w.r.t. wanpipe looks good as per wanpipe debugging link then change then change the "impedance mode" to 0 and "rx level" to "43db" in wanpipe configuration as shown below:
         sdla_fe_cfg->cfg.te_cfg.high_impedance_mode = 0;
         sdla_fe_cfg->cfg.te_cfg.rx_slevel = WAN_TE1_RX_SLEVEL_43_DB;
This is because in case of No tap isolation if we enable high impedance then the amplification becomes too HIGH which distorts the signal.
NOTE: By default for tapping mode high impedance is set to 1 and Rx level is set to 12DB.  

Q. Sample Tapping application getting "Too many open files" error ?

Ans.  If you are getting "Too many open" files error which means tapping application failed to open the file due to reaching system max open file limit. Please check your system limit by "ulimit -Hn"/"ulimit -Sn" to see hard and soft limit. If it is around 1024 or very low then increase that to max i.e. "ulimit -n 65000". 

Q. How we can play the file recorded using sangoma tapping solution?

Ans. We can use audacity tool in order to listen to the files as recorded by sangoma tapping solution.
          
         Steps to hear the Files recorded:

• Step 1: Open file recorded in audacity tool.

• Step 2: Goto File then import and then RawData.

• Step 3: Select the file you want to listen.

  For ISDN:

• Step 4: Set Encoding Type as ‘Ulaw’, Byte Order as ‘No endianess’, Channels as ‘1channel (Mono)’, Start offset as ‘0’ bytes, Amount of import as ‘100’ % and Sample rate as ‘8000’ Hz.

             For ISUP:

• Step 4: Set Encoding Type as ‘Alaw’, Byte Order as ‘No endianess’, Channels as ‘1channel (Mono)’, Start offset as ‘0’ bytes, Amount of import as ‘100’ % and Sample rate as ‘8000’ Hz.

• Step 5: Select Import and start listening to the recorded file.

Q. To which port tapping cable needs to be connected and cable pinouts?

 Ans. Tapping can be achieved using Sangoma TDM SDK either using Sangoma Tap Box or without using Sangoma Tap Box.

• With Sangoma Tap Box:

  • For A101/102/104 Card:

    • Tx NET port of Tap Box is connected to Port N of Sangoma Card.

    • Tx CPE port of Tap Box is connected to Port N+1 of Sangoma Card.

  • For A108/A116 Card:
    
    

    • Rx pinout of Tx NET port of Tap Box is connected to Rx of Port N of Sangoma Card.

    • Rx pinout of Tx NET port of Tap Box is connected to Rx of Port N+1 of Sangoma Card.

          NOTE: Please refer to the link for Pinout of A108 and Sangoma Tap Box
                   

Without Sangoma Tap Box:

• For A101/102/104/108/116 Card:

  • Rx of port (i.e pinout 1 & 2 in case of NT) is connected to Rx of Port N of Sangoma Card

  • Rx of port (i.e. pinout 4 & 5 in case of TE) or Tx of port (i.e. pinout 4 & 5 in case of NT) is connected to Rx of Port N+1 of Sangoma Card

         NOTE: In case of A108/A116 since single RJ 45 consists of two ports in such a case if we need to use both the ports in order to tap E1 then Rx of port should be connected to Rx of Port N of A108 (i.e. pinout 1 & 2) and Tx of port should be connected to Rx of port N+4 of A108 (i.e. pinout 3 & 5).

A108 Connect pinouts:

1 -> Port N     – Rx+
2 -> Port N     – Rx-
3 -> Port N+4 – Rx+
4 -> Port N     – Tx+
5 -> Port N     – Tx-
6 -> Port N+4 – Rx-
7 -> Port N+4 – Tx+
8 -> Port N+4 – Tx 

NOTE: For information for pinouts refer to below links:

1. Tapping Cable pinouts

2. Cable pinouts