Propose which modifications can be made in SDP (Section 6)

[ekr]

Section 6 indicates that programmers can edit the SDP and lists changes which can and cannot be made. It explicitly is preliminary and needs to be fleshed out.

[fluffy]

There are three categories - must reject, must act on , and ones that the browser can do whatever it wants but if it is not acted on then an error is generated

[fluffy]

General approach is most things are in the "browser can do what it wants case"

[martinthomson]

Discussed in DC: this applies only to changes on the local side; the gap between createOffer/createAnswer and setLocalDescription.

Proposed path is to mandate one of two actions:

• Accept the changes and apply them
• Reject the changes outright

We will enumerate certain changes that fall into either category, but these lists will not be exhaustive. All unspecified changes will either be accepted or rejected, and that decision will be left to the browser, but they cannot be ignored.

Obviously, some types of changes will be ignored. For instance, reordering of a= lines might not be detected as a change. These might carry semantics (as a=group-id does), but we can't require perfect detection.