23.1403GPPFunctional descriptionMultimedia Messaging Service (MMS)Stage 2TS
Figure 11: Example of MMS interaction with Facsimile Services based on ITU-T.37
For the transfer of facsimile data via store-and-forward mechanisms ITU-T.37  procedures have been standardised. These are identified as appropriate in the MMS environment for the interworking with T.30  facsimile services. What the relevant MMSE parts are supposed to look like for a T.37 approach is depicted in figure 11. The MMS Relay interfaces with a T.37 Fax Gateway. For the Gateway’s communication with the MMS Relay the appropriate protocol is SMTP. I.e., the protocol to be used on the interface between MMS-Relay and the Fax GW is identical to the one used between different MMS-Relays as specified in section 6.6.
Note: The MMS Relay – MMS Server interface is not in the scope of this subsection but described in A.3.
Towards the PSTN the Fax-GW terminates the T.30 facsimile protocol. Mobile terminated fax data will be converted into TIFF image format and forwarded to the MMS Relay as an attachment in an IETF internet email. In case of mobile originated fax messages the Fax-GW receives a written email provided with the receiver’s fax number from the MMS Relay. Depending on the functions of the Fax-GW this email may contain plain text only or additional attachments, too. Although T.37 requires only TIFF format support there are Fax-GWs out on the market that permit many different formats to be included.