[asterisk-users] T.38 gateway ATA

[Jeff LaCoursiere]

On 09/25/2012 10:34 AM, Sylvain Rochet wrote:
> Hi Jeff,
>
>
> On Tue, Sep 25, 2012 at 10:11:27AM -0500, Jeff LaCoursiere wrote:
>> Aha!  That is what I am looking for.  What firmware rev are you
>> using on the 3102?
> 5.1.12 on SPA8000, 5.1.10(GW) on SPA3102, there is probably new releases
> from Cisco, at the time I builded the T.38 network those were the latest
> releases.
>
> Here is my SPA3102 configuration that I changed or are relevant to FAX/T.38:
>
> Network Jitter Level: very high
> Jitter Buffer Adjustment: disable
> Call Waiting Serv: no
> Three Way Conf Serv: no
> Echo Canc Enable: no
> Echo Canc Adapt Enable: no
> Echo Supp Enable: no
> FAX CED Detect Enable: yes
> FAX CNG Detect Enable: yes
> FAX Passthru Codec: G711a
> FAX Codec Symmetric: yes
> FAX Passthru Method: NSE
> DTMF Tx Mode: Normal
> FAX Process NSE: yes
> FAX Disable ECAN: yes
> FAX Enable T38: yes
> FAX Tone Detect Mode: caller or callee
>
> Note that my Asterisk is also configured to do Fax Tone Detect and ask
> my ATA to switch to T.38 before my ATA ask Asterisk to do so, thereforce
> I don't know if ATA Fax Tone Detection work correctly.
>
>
>> So if I am parsing you correctly, the asterisk server the ATA is
>> registered to is *also* a T.38 gateway, as you have directly connected
>> ISDN?
> Yes, this is also a T.38 gateway, my goal was to use T.38 from my ATA to
> Asterisk over my non-isochronous IP network. T.38 gateway is supported
> since Asterisk >= 10 and you don't need it since you are doing T.38
> passthru, but you need a device somewhere on the path able to detect the
> FAX preamble and ask to switch the data channel from ulaw/alaw to T.38.
>
>
> Sylvain
>

Thanks for the info Sylvain, that is just what I was looking for. Hoping 
to find that a lower model has the same feature set (don't really need 
the FXO port)... I am playing with an SPA122 right now, which seems to 
have the same options available you mention above. I'll load the latest 
firmware and report my experiences for posterity.

Cheers,

j