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10. Summary of Changes from RFC 4566

This document obsoletes [RFC4566]. The following is a summary of the changes from RFC 4566:

Major Changes​

  1. Deprecation of the "k=" line: The "k=" line for conveying encryption keys has been deprecated. Modern key exchange mechanisms such as DTLS-SRTP [RFC5763] SHOULD be used instead.

  2. Updated ABNF Grammar: The ABNF grammar in Section 9 has been updated for clarity and to align with RFC 5234.

  3. Updated Security Considerations: Section 7 has been significantly expanded to address modern security threats and to recommend current best practices.

  4. Clarifications on UTF-8 and Character Sets: Text has been clarified regarding the use of UTF-8 encoding and the "a=charset:" attribute.

  5. Updated IANA Considerations: Section 8 has been updated to reflect current IANA registry procedures and to reference RFC 8126.

Minor Changes​

  1. Terminology Updates: Various terms have been updated to align with current usage and to improve clarity.

  2. Reference Updates: Numerous references have been updated to point to current specifications. For example:

    • Updated references to HTTP specifications (RFC 7230)
    • Updated references to TLS specifications (RFC 8446)
    • Updated references to SIP specifications

  3. Clarifications on Media Descriptions: Additional clarifications have been added regarding the handling of media descriptions and attributes.

  4. IPv6 Address Handling: Clarifications added regarding IPv6 address representation.

  5. Multicast Address Handling: Additional guidance on multicast address usage.

  6. Bandwidth Specification: Clarifications on the interpretation of bandwidth values.

  7. Time Zone Handling: Improved description of time zone adjustment mechanisms.

  8. Attribute Extensibility: Enhanced description of attribute extension mechanisms.

  9. URI Handling: Updated guidance on URI usage within SDP.

  10. Media Type Registration: Updated "application/sdp" media type registration.

Editorial Changes​

  1. Numerous editorial corrections and clarifications throughout the document
  2. Improved formatting and structure
  3. Updated examples to reflect current practices
  4. Corrected typographical errors from RFC 4566
  5. Improved consistency in terminology usage

Backward Compatibility​

This specification maintains backward compatibility with RFC 4566 with the following exception:

  • The "k=" line, while deprecated, is still syntactically valid for parsing purposes. However, implementations SHOULD NOT generate new session descriptions using the "k=" line.

Implementations conforming to this specification can process session descriptions conforming to RFC 4566, with the understanding that the "k=" line is now deprecated.

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