QUESTION Do I have to enable T38 passthrough?

[_alx_]

I have a new piaf installation with sip extensions for my users and a couple of dahdi extensions for fax machines. The pbx has a single sip trunk and through there I have ten DIDs. Two of the DIDs are for the fax machines. I have configured the inbound routes to target the two dahdi extensions that have the fax machines connected.

So, do I have to enable the T38 passthrough (on my system/trunk) to receive and send fax from these two analog faxes?

I am asking because in the Asterisk documentation I read the following

T.38 Passthrough allows Asterisk to carry T.38 UDPTL from one T.38-speaking endpoint to another T.38-speaking endpoint. Asterisk does not modify the media.

https://wiki.asterisk.org/wiki/display/AST/T.38 Fax Gateway

The Dahdi extensions I guess there are not T38 capable so I think that it is not needed but I would like the community opinion.