# DSP files

The following files are included with Natural Access:

DSP file | Description
--- | ---
adsir(_j).f41 | Contains the caller ID function that decodes the modem burst that occurs between the first and second rings on a loop start line. In addition, it contains the FSK data receiver. (_j) is the V.23 variant.
adsix(_j).f41 | Contains the FSK data transmitter. (_j) is the V.23 variant.
amr.f41 | Contains AMR play and record functions.
callp.f41 | Contains voice and tone detectors used for call progress detection. Use for any outgoing or two-way trunk protocol and for call progress analysis.
cg6conf.f41 | Contains functions for conferences that use only a single DSP. See readme_cnf.txt for more information.
cgcnfm.f41 | Contains functions for conferences across multiple DSPs. This is for the master DSP. See readme_cnf.txt for more information.
cgcnfs.f41 | Contains functions for conferences across multiple DSPs. This is for a slave DSP. See readme_cnf.txt for more information.
dtmf.f41 | Contains the DTMF receiver, energy detector, silence detector, and precise tone filter typically used for cleardown.
dtmfe.f41 | A variant of dtmf.f41, optimized for use with the echo canceler (echo.f41). It yields better talk-off resistance, but requires the echo canceler to achieve the best cut-through performance. Note: You must use echo cancellation with this function.
echo.f41 | Contains the echo cancellation function. The echo canceler removes reflected transmit channel energy from the incoming signal, which improves DTMF detection and voice recognition while playing. CG board DSP echo functions are characterized by two parameters: tail length and adaptation rate. Tail length represents the maximum duration of the echo that can be cancelled, in ms. The adaptation rate specifies the percentage of the echo canceler filter coefficients that are adapted every period. The CG 6565 echo function has an adapt period of 8 ms. Therefore, an echo function with a 20 ms tail length and 100% rate will adapt all the coefficients in 8 ms while the same function with a 25% rate will adapt in 32 ms. Note: Substitute dtmfe.f41 for dtmf.f41 when using the echo canceler.
echo_v3.f41 | Contains an improved echo cancellation function. This echo canceler presents a higher performance than the one in echo.f41. It also has a maximum tail length of 64 ms. Note: Substitute dtmfe.f41 for dtmf.f41 when using this echo canceler.
echo_v4.f41 | Combines echo_v3.f41 functionality with comfort noise generation and tone disabling enhancements.
f_amr.f41 | Contains AMR encoder and decoder for voice over IP transmissions. See readme_amr.txt for more information.
f_evrc.f41 | Contains EVRC encoder and decoder for voice over IP transmissions. See readme_evrc.txt for more information.
f_faxt38.f41 | Contains T.38 encoder and decoder for voice over IP transmissions. See readme_faxt38.txt for more information.
f_g711.f41 | Contains G.711 encoder and decoder for voice over IP transmissions. See readme_g711.txt for more information.
f_g711vad.f41 | Contains G.711 VAD encoder and decoder for voice over IP transmissions. See readme_g711.txt for more information.
f_g723.f41 | Contains G.723 encoder and decoder for voice over IP transmissions. See readme_g723.txt for more information.
f_g726.f41 | Contains G.726 encoder and decoder for voice over IP transmissions. See readme_g726.txt for more information.
f_g729a.f41 | Contains G.729a encoder and decoder for voice over IP transmissions. See readme_g729a.txt for more information.
f_gsm_fr.f41 | Contains GSM-FR encoder and decoder for voice over IP transmissions. See readme_gsm_fr.txt for more information.
f_ilbc_20.f41 | Contains iLBC 20 (20 ms frames) encoder and decoder for voice over IP transmissions. See readme_ilbc.txt and RFC 3951 for more information.
f_ilbc_30.f41 | Contains iLBC 30 (30 ms frames) encoder and decoder for voice over IP transmissions. See readme_ilbc.txt and RFC 3951 for more information.
g723.f41 | Contains ITU G.723.1 play and record functions for both 5.3 kbit/s and 6.4 kbit/s rates. The codec data is output as raw bytes of the encoded 30 ms frames.
g726.f41 | Contains ITU G.726 ADPCM play and record functions. G.726 is a standard for 32 kbit/s speech coding. These functions require considerably more DSP processing time than the functions in voice.f41. g726.f41 is required if you start play and record with an encoding type of ADI_ENCODE_G726.
g729a.f41 | Contains ITU G.729A play and record functions. The 8 kbit/s codec data is output as raw bytes of encoded 10 ms frames.
gsm_ms.f41 | Contains MS-GSM play and record functions. The 13 kbit/s full rate GSM speech codec outputs data in Microsoft formatted frames.
gsm_mspl.f41 | Contains identical play and record functions as the gsm_ms.f41 except that the maximum output power of the play function is maintained.
ima.f41 | Contains IMA ADPCM play and record functions. IMA is a standard for 32 kbit/s speech encoding.
mf.f41 | Contains the multi-frequency receiver required for any trunk control protocol (TCP) that uses MF signaling, and is required by the MF detector.
nmsfax.f41 | Contains NaturalFax send and receive functions. See readme_nfx.txt for more information.
oki.f41 | Contains play and record functions for OKI ADPCM speech encoding, at 24 kbit/s or 32 kbit/s (used to play and record compatible voice files).
ptf.f41 | Contains precise tone filters. Typically used for CNG, CED, or custom tone detection.
rvoice.f41 | Contains PCM play and record functions. rvoice.f41 is required to play or record with an encoding of ADI_ENCODE_MULAW, ADI_ENCODE_ALAW, or ADI_ENCODE_PCM8M16.
rvoice_vad.f41 | Contains PCM play and record functions. Record functions can enable the voice activity detection (VAD) capability. rvoice_vad.f41 is required to play or record with an encoding of ADI_ENCODE_MULAW, ADI_ENCODE_ALAW, or ADI_ENCODE_PCM8M16.
tone.f41 | Contains the tone generation function. This file is required for any trunk protocol except NOCC. It is also required for generating tones, generating DTMF tones, MF tones, initiating dialing, and for generating a beep tone with any record function.
voice.f41 | Contains NMS ADPCM play and record functions. The compressed speech is in a framed format with 20 ms of data per frame. Speech is compressed to 16, 24, or 32 kbit/s or stored as uncompressed mu-law or A-law (64 kbit/s). This file is required to play or record with encoding values of ADI_ENCODE_NMS_16, ADI_ENCODE_NMS_24, ADI_ENCODE_NMS_32, or ADI_ENCODE_NMS_64.
wave.f41 | Contains play and record functions for PCM speech in formats commonly used in WAVE files, including 8 and 16 bit 11 kHz sampling.

For all NaturalAccess ISDN Software installations, load the following files:

- dtmf.f41

- callp.f41

- tone.f41

Additional .f41 files are available for Fusion and fax configurations. For more information, refer to the Dialogic® NaturalAccess™ Fusion™ VoIP API Developer’s Manual and Dialogic® NaturalAccess™ NaturalFax™ API Developer’s Manual .

The f41info utility can be used to list DSP file resources. For more information, refer to f41info - Displaying DPF file resource usage.