Solved Is anyone using t38modem for sending faxes?

[Eli55]

Hello,

This little utility is a perfect solution for sending faxes using windows fax and scan without additional hardware (56k modem and analog gateway). It basically creates a virtual modem and connects straight to SIP. I was able to get it working for outgoing faxes, however it only works with regular extensions and not FAX extensions. When trying to connect it to a FAX extension, SIP registration doesn't work because of credentials.

Could this be a problem with 3cx? it registers perfectly with the SIP trunk provider as well. I also have an issue connecting grandstream HT802 to a FAX extension, similar issue.

 

[cobaltit]

Is your 3CX hosted? Fax extensions can only be registered as local.

 

[Eli55]

Local, not hosted. Same VLAN. I'm using a hostname though, not IP address. But it doesn't work using the IP address as well.

 

[YiannisH_3CX]

What are you using as credentials? I just registered an ATA and an IP phone on a Fax extension and both register just fine.

 

[eddv123]

Then we have a possibility of a network level issue here, is the device within the same subnet as the IP PBX ? If within the same VLAN then communications should not be an issue.

There is no (as far as I am aware) PING functionality on the Grandstream, but can you PING the device from the PBX, and if so does running wireshark show the REGISTER messages reaching 3CX.

I'm using a hostname though

In regards to the hostname part (regardless of IP success or not) you need to have a local DNS resolving record for private IP >> Hostname, if this is in place and you run an nslookup locally does it resolve correctly ?

Also check the IP blacklist on the PBX and check your ATA is not on there.

 

[Eli55]

Then we have a possibility of a network level issue here, is the device within the same subnet as the IP PBX ? If within the same VLAN then communications should not be an issue.

There is no (as far as I am aware) PING functionality on the Grandstream, but can you PING the device from the PBX, and if so does running wireshark show the REGISTER messages reaching 3CX.



In regards to the hostname part (regardless of IP success or not) you need to have a local DNS resolving record for private IP >> Hostname, if this is in place and you run an nslookup locally does it resolve correctly ?

Also check the IP blacklist on the PBX and check your ATA is not on there.

Grandstream device issue was fixed by doing a SSH reset.

t38modem virtual modem program is giving me bad credentials error but i'm 100% sure the credentials are correct. I configured IP blacklist to allow the whole VLAN. 2 DNS servers have correct config, nslookup works fine.

What are you using as credentials? I just registered an ATA and an IP phone on a Fax extension and both register just fine.

Per t38modem help file:
SIP options:
--no-sip : Disable SIP protocol.
--sip-audio str : Use OPAL-Enable-Audio=str route option by
default. May be used multiple times.
--sip-audio-list : Display available audio formats.
--sip-disable-t38-mode : Use OPAL-Disable-T38-Mode=true route option by
default.
--sip-t38-udptl-redundancy str
: Use OPAL-T38-UDPTL-Redundancy=str route option by
default.
--sip-t38-udptl-keep-alive-interval ms
: Use OPAL-T38-UDPTL-Keep-Alive-Interval=ms route
option by default.
--sip-proxy [user:[pwd]@]host
: Proxy information.
--sip-register [user@]registrar[,pwd[,contact[,realm[,authID]]]]
: Registration information. Can be used multiple
times.
--sip-listen iface : Interface/port(s) to listen for SIP requests
: '*' is all interfaces (default tcp$*:5060 and
: udp$*:5060).
--sip-no-listen : Disable listen for incoming calls.


I'm doing:
--sip-register [email protected],PASSWORD,880,domain.3cx.us,AUTHID


pass and authid taken from extension settings. i tried to swap them as well and no success. Regular extensions register fine with pbx but fax extensions are having issues.

edit: i also tried swapping the host name for IP, like [email protected]. i also set it to listen on udp 5060, which works for regular extensions.

 

[eddv123]

does running wireshark show the REGISTER messages reaching 3CX.

To quote myself from a previous post, I would recommend that If you are still experiencing registration issue to do the above. It will either tell you the messages are not reaching, or give you the response from 3CX.

 

[Eli55]

To quote myself from a previous post, I would recommend that If you are still experiencing registration issue to do the above. It will either tell you the messages are not reaching, or give you the response from 3CX.

I'm not too familiar with wireshark

Activity log is showing this:
Reason: Credentials don't match, check that authorization-ID and password match the ones in extension settings

It does reach the pbx but for some reason the credentials are not going through..

 

[eddv123]

Yes that looks to me to be normal authentication (as a test) you could set your authentication ID as your extension number (not a secure option) and use this, if I recall I did something similar with Grandstream before and it worked (obviously changing the settings in the Grandstream also).

 

[Eli55]

Yes that looks to me to be normal authentication (as a test) you could set your authentication ID as your extension number (not a secure option) and use this, if I recall I did something similar with Grandstream before and it worked (obviously changing the settings in the Grandstream also).

This worked perfectly. Thank you.