VPIM Voice Message MIME Sub-type Registration
obsoleted by
- rfc-3801 — Voice Profile for Internet Mail - version 2 (VPIMv2)
obsoletes
- rfc-1911 — Voice Profile for Internet Mail
Extracted elements (12)
A version parameter is required to distinguish VPIM v2 content from the earlier VPIM v1 definition in RFC 1911, enabling receivers to apply the correct processing rules for each version.
multipart/voice-message is defined as identical to multipart/mixed so that pre-MIME or non-VPIM systems can still process the content, losing only the identification as a voice message. A preamble can be inserted for pre-MIME software recipients.
Systems conforming to VPIM v1 (RFC 1911) may not include the required version parameter. Recipients encountering a missing version parameter should still accept and handle the message, though VPIM v1 positional identification would likely be lost.
All VPIM Messages MUST contain the multipart/voice-message sub-type to identify the wrapping of a voice message.
The order of audio segments in a multipart/voice-message MUST NOT be assumed. The order that contents appear SHOULD be the order in which they are presented to the user.
The version parameter value is '2.0' for VPIM v2 conformant content. Should further revisions occur, there MUST be backwards compatibility such that systems implementing version n can read version 2, and vice versa.
The multipart/voice-message MIME sub-type wraps the components of a single voice message. It is semantically and syntactically identical to multipart/mixed, so systems that do not understand the sub-type can safely interpret it as multipart/mixed.
The version parameter default value (when absent) is 1, indicating conformance to VPIM v1 (RFC 1911). A value of '2.0' indicates conformance to VPIM v2 (RFC 2421).
Typical multi-segment voice messages order content as: spoken name of originator (max 12 seconds), spoken subject (max 20 seconds), and the voice message itself, though this order must not be assumed.
When version=2.0, only specific media types are valid contents of multipart/voice-message: audio/*, image/*, message/rfc822, and application/directory.
Registers the MIME sub-type multipart/voice-message with IANA for use in Voice Profile for Internet Mail (VPIM) systems. Required parameters are 'boundary' and 'version'; no optional parameters are defined.
The multipart/voice-message sub-type identifies content as a voice message. In some environments, this loss of content anonymity may constitute a security concern.