Can't fax with Grandstream HandyTone 286

I just got my Grandstream HandyTone 286 in the mail a few days ago, and I’ve managed to get it to work fine when I hook up an analog phone, but I’m unable to get my faxes to work when I hook up my regular fax machine to the line. I am using ulaw (which I was told would be okay for using faxes on) - has anyone set up something similar to this before and can help me out?

sending faxes over ulaw might work, if its on a lan for example.

Its not recommended, the recommended way is to use a t.38 capable device, and patch asterisk to do t.38

I will look into that. The 286 is t.38 capable, can I assume that any fax machine can then send a regular ‘fax’, and that the handytone and asterisk will take care of the rest?

Can anyone give me any resources for either making my handytone 286 work for fax-passthrough mode (like it says it should), or patching asterisk with t.38?

The only info I can find on t.38 and asterisk implies that it doesn’t work…