Asterisk 1.6 T.38 faxing issue

We have an ATA attached to a fax machine that we're not able to reliably send or receive T.38 faxes with. The trunks (Broadvox) are configured for T.38 and so is the ATA (Linksys SPA3102). Here is the environment: AsteriskNOW 1.7.1 Asterisk 1.6.2.11 FreePBX 2.8.1.3 Here is the layout of the network: Broadvox --> WAN --> Firewall (NAT) --> ATA --> FAX Machine I have verified by taking captures that the transmission switches over to T.38 but most attempts result in a hangup around 30 seconds into the call. There are a variety of issues found in the Asterisk logs (included below) but in the research I've done I haven't found any resolution. WARNING[5836] udptl.c: (SIP/4232879579): UDPTL asked to send 41 bytes of IFP when far end only prepared to accept 38 bytes; data loss will [login to view URL] may need to override the T38FaxMaxDatagram value for this endpoint in the channel driver configuration. WARNING[22599] rtp.c: RTP Read too short [Mar 24 14:44:58] WARNING[22599] rtp.c: RTP Read too short [Mar 24 14:44:58] WARNING[22599] rtp.c: RTP Read too short [Mar 24 14:44:58] WARNING[22599] rtp.c: RTP Read too short [Mar 24 14:45:04] WARNING[22599] rtp.c: RTP Read too short WARNING[24064] udptl.c: T38FaxUdpEC in [login to view URL] is no longer supported; use the t38pt_udptl configuration option in [login to view URL] instead. WARNING[24064] udptl.c: T38FaxMaxDatagram in [login to view URL] is no longer supported; value is now supplied by T.38 applications. If you are an Asterisk expert and familiar with fax configuration required for our environment, we'd appreciate your help.