This Recommendation defines the procedures to be applied to allow Group 3 facsimile transmission between terminals where in addition to the PSTN or ISDN a portion of the transmission path used between terminals includes an IP network, e.g., the Internet.

This revision of T.38 specifies in Annex B the use of the h245Tunnelling flag during H.323 call establishment for T.38 devices that do not support H.245, and, in Appendix III, corrects errors in the procedure examples forH.248 call establishment.