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In this section:

Table of Contents
maxLevel4

 

The

Spacevars
0series4
 includes an option of enabling the “V.8” detector on each DSP channel for V.34 fax.  The V.8 detector is responsible for detecting the early signaling protocol used for setting up high speed modem and high speed fax sessions.This allows the
Spacevars
0product
 to determine if a call is modem or fax, and then process the call accordingly.

To enable V.8 detector, set T.38 protocol version to “3”. The CLI syntax is shown below . Refer to Packet Service Profile - CLI  and Media Profiles - Packet Service Profile (EMA)).

Code Block
languagenone
% set profiles media packetServiceProfile <unique_profile_name> t38 protocolVersion 3

The V.8-capable calling fax machine or a calling data modem, starts the V.8 signalling by sending a CM (Call Menu) signal in response to an ANSAm signal (amplitude modulated 2100 Hz with phase reversals) from anwering fax machine. Physical layer for CM is ITU-T V.21 FSK modulation using lower channel (980 Hz for mark and 1180 Hz for space). ANSAm signal is generated by answering fax as well as modem telephony terminals, as a result SBX cannot determine precise intent of this call merely by analyzing ANSAm. This is possible by analysis of CM because CM contains an information field called "call function" which clarifies capability and intent of the calling terminal.

V.8 signal analysis module in DSP demodulates the CM and decodes the demodulated bits to learn about calling machine capability and intent. When enabled, V.8 module, determines if the CM is from a V.34 data modem, a Super G3 (V.34) fax machine or a group 3 fax machine and passes this information to call processing layer software so that call processing software then can take appropriate actions such as initiate a transition to T.38 protocol to support fax or initiate a transition to G.711 codec to support modem, based on packet service profile configurations.

V.8 Detector for SPS100 Card

The table below list the number of voice channels with and without V.8 on SPS100 per card:

Caption
0Table
1Number of voice channels with and without V.8 on SPS100 per card
Codec

Number of channels without V.8

Number of channels with V.8

G.7118544 6240

G.711 No SS

10272 7104

G.729A/G.729AB

5184 4224

G.723.1/G.723.1A

57604608

G.726/G.726 SS

57604608

iLBC/iLBC SS            

3648 3072

AMR               

4224 NA
EFR4224 NA
EVRC3168 NA
EVRCB2304 NA
WAMR ( G.722.2)2304 NA
G.7225760 4608
G.722.14992 4128
OpusNANA
SILK-NBNANA
SILK-WBNANA
T.38 version 04800NA
T.38 version 31344NA

V.8 Detector for DSP20 Card

The table below lists the number of voice channels with and without V.8 on DSP20 per card:

Caption
0Table
1Number of voice channels with and without V.8 on DSP20 per card
Codec

Number of channels without V.8

Number of channels with V.8

G.71115681152

G.711 No SS

2000

1368

G.729A/G.729AB

1168        920

G.723.1/G.723.1A

1104880

G.726/G.726SS

1104880

iLBC / iLBCSS

696600

AMR               

992NA
EFR992NA
EVRC608NA
EVRCB440NA
WAMR (G. 722.2)504NA
G.7221104880
G.722.1960784
Opus144NA
SILK-NB 560NA
SILK-WB 400NA
T.38 version 0920NA
T.38 version 3248NA

V.8 Detector for DSP25 Card

The table below lists the number of voice channels with and without V.8 on DSP25 per card:

Caption
0Table
1 Number of voice channels with and without V.8 on DSP25 per card
Codec

Number of channels without V.8

Number of channels with V.8

G.7117840 5760

G.711 No SS  

10000 6840

G.729A/G.729AB

5840 4600 

G.723.1/G.723.1A         

5520

4400

G.726/G.726 SS        

5520

4400

iLBC/iLBCSS            

34803000

AMR               

4960NA
EFR4960NA
EVRC3040 NA
EVRCB2200 NA

WAMR(G.722.2)

2520 NA
G.72255204400
G.722.148003920
Opus720NA
SILK-NB 2800NA
SILK-WB 2000NA

T.38 version 0

4600NA

T.38 version 3

1240NA

V.8 Detector for DSP-LC Card

The table below lists the number of voice channels with and without V.8 on DSP-LC per card:

Caption
0Table
1Number of voice channels with and without V.8 on DSP-LC per card
Codec

Number of channels without V.8

Number of channels with V.8

G.71143904 32256

G.711 No SS

56000 

38304

G.729A/G.729AB

32704 25760

G.723.1/G.723.1A          

30912 24640

G.726/G.726 SS       

3091224640

iLBC/iLBC SS 

19488 16800

AMR               

27776 22624
EFR2777622624
EVRC17024 14784
EVRCB12320 11200

WAMR(G.722.2)

14112 12544
G.72230912 24640
G.722.126880 21952
Opus4032NA
SILK-NB 15680NA
SILK-WB 11200NA

T.38 version 0

25760NA

T.38 version 3

6944NA

 

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