Missing Text Parts from MMS Messages

The customer was using NowSMS as an MMSC, and encountered two devices, the Motorola RAZR V8 and ROKR Z6, which were unable to receive any text content within an MMS message.

As a first step of troubleshooting, we recommended that the customer disable “content adaptation” by the MMSC to determine if the problem was related to content adaptation. (This setting is labeled “Enable Dynamic Image + Audio Conversion” in the MMSC configuration.)

The problem did go away with content adaptation disabled. However, disabling this support was not considered to be a permanent solution for the customer.

Upon further investigation, it was determined that the content adaptation problem was caused by errors in the User Agent Profiles (UAProf files) published by Motorola for these devices. The NowSMS MMSC consults these profiles to determine what content types are supported by the MMS client in the receiving handset. The profiles for these devices included a list of content types supported by the MMS client, but did not include plain text (text/plain) as one of the supported content types.

The NowSMS MMSC caches UAProf files in the UAPROF subdirectory of the NowSMS installation. The user was able to manually edit the motorazrv8.rdf and motorokrz6.rdf files in this directory to add support for the content typle “text/plain”.

The supported MMS content types are listed in the “MmsCcppAccept” section of the UAProf file. Simply adding <rdf:li>text/plain</rdf:li> within this section of the file is all that is necessary to add support for the “text/plain” content type.

Future versions of the NowSMS MMSC will always assume that “text/plain” is a supported content type within MMS messages, even if there is an error in the UAProf file published by the handset manufacturer.