FAX T.38

[rabbitman]

The Faxing will not work when you enable T.38. When I diable it works.
why is that?

[pc44]

Hi rabbitman,

When you disable T.38, your fax attempt is likely using G711 instead.  Many users have noted success with G711 -- more so than with T.38.  For some reason, I have yet to hear of any OBi user successfully faxing via T.38. 

If anyone out there has been successful with T.38 on the OBi202, please speak up.   I'd like to get this working myself but have placed it on the back burner due to the unsuccessful feedback by others in the forum.

pc44

[QBZappy]

When you disable T.38, your fax attempt is likely using G711 instead.  Many users have noted success with G711 -- more so than with T.38.  For some reason, I have yet to hear of any OBi user successfully faxing via T.38. 

I believe that the voice SP needs to support T.38.

[pc44]

I believe that the voice SP needs to support T.38.

You are correct, as usual.  Callcentric and Anveo Direct support T.38, but have you heard of anyone that has been successful with T.38 on the OBi202 yet?

[QBZappy]

pc44,

I can't recall anyone reporting using T.38 with success.

[jjtricket]

T.38 is checked on my obi202 and faxes are working

[QBZappy]

What service provider are you using?

[jjtricket]

Just using GV

[QBZappy]

Ah, in that case GV transcodes everything into G711. That seems to be a false positive.

Soryy pc44, we are still looking for a winner. No cigar for you jjtricket this time. 

[pc44]

Ah, in that case GV transcodes everything into G711. That seems to be a false positive.

Soryy pc44, we are still looking for a winner. No cigar for you jjtricket this time. 

Awwww 

[jjtricket]

Sorry to burst that bubble, but thanks for your help!

[Static]

I'm using an obi202 with anveo for fax. I assume I'm using t.38..  I'm kinda a voip noob so i really have no idea. anyway, whatever I'm doing, it's BUGGY BUGGY BUGGY. it can take 2 or 3 tries before a fax successfully sends or receives..

[pc44]

Static,

I was getting all excited there for a minute, and then wham! you slammed the door on me.   Anveo does support T.38, as QBZ referenced earlier; so I was hoping you would have some success to report.  But "buggy buggy buggy" doesn't sound good at all.

Are you able to go to your Call Status in the OBi *during* the fax transmissions?  I wonder what codec it is reporting to you during these fax attempts.  I would assume T.38, but it would be nice to confirm whether that is actually in play during your 2 or 3 attempts.

Thanks for this feedback; it's valuable to me,
pc44

[Diana]

Correct me if I wrong, but T.38 is NOT a codec, but a fax protocol.

Static,

Are you able to go to your Call Status in the OBi *during* the fax transmissions?  I wonder what codec it is reporting to you during these fax attempts.  I would assume T.38, but it would be nice to confirm whether that is actually in play during your 2 or 3 attempts.

[Billt928]

I have had a trouble ticket open with both OBI and Callcentric about issues with T.38 for over a month

Seems I can send faxes fine but receiving them is a huge issue. The line just disconnects when the fax answers and starts negotiating the connection. OBI techs told me that Callcentric was issuing a BYE and disconnecting the call. When T.38 is disabled Callcentric accepts the T.38 then switches to G711.
Seems Callcentric sees something going on when logging the calls, but only informs me that something is strange. I have not been told what that is. Though this week they are doing an internal port to a diffrent carrier.

I can only hope that it works. Also the setting that Callcentric provided at http://www.callcentric.com/support/device/obihai/obi202 worked better than the Obitalk default settings. Before changing them I was having issues with outbound faxes also

[pc44]

Correct me if I wrong, but T.38 is NOT a codec, but a fax protocol.

Static,

Are you able to go to your Call Status in the OBi *during* the fax transmissions?  I wonder what codec it is reporting to you during these fax attempts.  I would assume T.38, but it would be nice to confirm whether that is actually in play during your 2 or 3 attempts.

I believe you are correct.  I am trying to determine if T.38 is in play during a fax attempt by some of the users here.  So far, it seems as though no one has reported success here with T.38.

[pc44]

I have had a trouble ticket open with both OBI and Callcentric about issues with T.38 for over a month

Seems I can send faxes fine but receiving them is a huge issue. The line just disconnects when the fax answers and starts negotiating the connection. OBI techs told me that Callcentric was issuing a BYE and disconnecting the call. When T.38 is disabled Callcentric accepts the T.38 then switches to G711.
Seems Callcentric sees something going on when logging the calls, but only informs me that something is strange. I have not been told what that is. Though this week they are doing an internal port to a diffrent carrier.

I can only hope that it works. Also the setting that Callcentric provided at http://www.callcentric.com/support/device/obihai/obi202 worked better than the Obitalk default settings. Before changing them I was having issues with outbound faxes also

Do keep us posted on this.  I do not know much about T.38, but hopefully you, Callcentric, or Obihai will find a solution.  Callcentric and Anveo are the only two T.38 supported providers that come to mind, and so far, we aren't seeing success.  My backup VoIP provider says they are "planning" to support T.38 "soon" (i.e. last month), but I am still waiting for them to roll this out.  If they do, I will be doing extensive testing to try to get mine working.

pc44

[Mango]

Bump.    If anyone has successfully used T.38 on the OBi202, please share!

[Billt928]

it now seems to be working as expected using T38 for most faxes (PSTN lines, OBI202 to OBI202 and others that support T38) Google numbers, HP Test Fax, Magic Jack it will re-invite to use G711U

ITSP SIP
ProxyServer = callcentric.com
RegistrarServer = callcentric.com
UserAgentDomain = callcentric.com
OutboundProxy = srv.callcentric.com

X_ProxyServerRedundancy = unchecked

X_DnsSrvAutoPrefix = enabled
X_PublicIPAddress = your public ip

ITSP General
DigitMap = (*xx.|*123|**275*x.|[3469]11|1xxxxxxxxxx|<1Your Area Code>[2-9]xxxxxx|<1>[2-9]xxxxxxxxx|011xx.|xx.|(Mipd)|[^*]@@.)


Voice Services > SPx Service
X_KeepAliveEnable = enabled
X_KeepAliveExpires = 120

Codec Profile A or B
G711U Codec
Priority = 1

G711A Codec
Priority = 2

All others disabled

You can tell your using T38 under call status (it does not show T38) but this line will change

Call Status
Audio Codec = tx=G711U; rx=G711U

Will change to when sending
Audio Codec = tx=; rx=G711U

After the re-invite to T38.

This is the result of many hours of testing with Obi and Callcentric senior support staff all working together to resolve the T38 issues I was having with the obi disconnecting the call when negotiating the T38 connection.

I hope this helps others with T38 issues

[QBZappy]

Billt928,

Thanks for sharing.