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New Member

Fax problem иoth inside and outside of a LAN


We are using CCM 4.3.1 for voip. and have some problem with fax receptions. Fax goes from one ata186 in our ccm to another and some strings in text are missing, fax goes outside of our network through vg as5400 and the pictures are same. We try to configure ata for fax detect for only g711 and nothing helps.


Re: Fax problem иoth inside and outside of a LAN

There are two ways in fax configuration, the first is G711 fax mode and the second is the fax passthrough.For G711 fax mode, the ATA is pre-configure for using G.711 for the specific port(s) and the port(s) is/are configure for no vad and no fax detection.the audio setting needs to be set to 0X00120012 (if both ports are to be used for fax), on the gateway router under the voip dial peer config,

you need to add 'fax rate disable', "codec g711alaw" (for Euro) and "no vad".

For Fax Pasthrough mode, the ATA will detect the fax tones coming from the machine and switch the

codec from G.723 or G.729 to G.711. For this config we need to set not only the AudioMode bits (0X00150015) but also the ConnectMode (0x908e2400) or (0x90002400) bits. however if the gateway router cannot recognise the 'modem passthrough nse ...' command, then you either need to use the fax mode or upgrade the router to 12.2.11T train or later.

Please note that if the G711 fax mode doesn't work properly, then you may need to use the fax pass through mode

New Member

Re: Fax problem иoth inside and outside of a LAN

Hi, thanks for answer.

We try to configure ata both pas through and fax mode like you say, but problem are still were. Ougoing fax are normal. Incoming missing some strings. Debug show nothing. Codecs -> 0 or 8 doesn't matter.

We try different config, soft, fax machines no different. What else shall we do to make fax work properly.

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