Code change:
Implementations MUST either abandon an association or re-key prior to allowing the sequence number to wrap. <del> Implementations MUST NOT allow the epoch to wrap, but instead MUST establish a new association, terminating the old association. </del> 4.2.2. When receiving protected DTLS records, the recipient does not have a full epoch or sequence number value in the record and so there is <del> some opportunity for ambiguity.  Because the full epoch and sequence number are used to compute the per-record nonce, failure to reconstruct these values leads to failure to deprotect the record, and so implementations MAY use a mechanism of their choice to determine the full values.  This section provides an algorithm which is comparatively simple and which implementations are RECOMMENDED to follow. </del> <ins> some opportunity for ambiguity.  Because the full sequence number is used to compute the per-record nonce and the epoch determines the keys, failure to reconstruct these values leads to failure to deprotect the record, and so implementations MAY use a mechanism of their choice to determine the full values.  This section provides an algorithm which is comparatively simple and which implementations are RECOMMENDED to follow. </ins> If the epoch bits match those of the current epoch, then implementations SHOULD reconstruct the sequence number by computing

Related discussion:
text: However, to my understanding the full epoch value are so rarely included in transmitted DTLS messages that its size have minimal implication on the overhead that it is not worth saving 4-bytes to be certain to have eliminated any practical limitation.
I think a 2-week WGLC and notifying the IESG will suffice.
FYI. We have now run into quite many problems with the interworking of semi-permanent DTLS/SCTP connections (lasting years) and DTLS 1.3: No Diffie-Hellman rekeying No post-handshake server authentication No rekeying of the exporter_secret 2^40.5 packets limit 2 minute MSL requirement 2^38.5 byte SCTP user message size limit Our initial plan was to just replace DTLS 1.2 with DTLS 1.3, leave DTLS/SCTP as is, but as the problems keep adding up we are now startnig to consider quite big changes to DTLS/SCTP 1.3 to make this work: URL Using new DTLS connections instead of KeyUpdate could potentially address the first five, but is a significant change.
Hi, Based on the problems long-lived DTLS/SCTP had with DTLS 1.3 (as well as DTLS 1.2 without renegotiation and respecting AEAD limits) we restructured DTLS/SCTP (RFC6083bis) to use parallel connections instead of relying on renegotiation and post-handshake messages. We think this quite easily solves all the problems we had without requiring any updates of DTLS 1.3. It also makes DTLS/SCTP less dependant on version specific DTLS mechanisms. It will hopefully work without changes with any future DTLS 1.4. URL We can now firmly RECOMMEND DTLS 1.3 which I think is very important. 5G is to a large degree replacing or complementing IPsec with TLS, DTLS, and DTLS/SCTP. I will do my best to transition 3GPP to DTLS 1.3 asap. FYI, 3GPP DTLS/SCTP associations have very long lifetimes (can be years), strive for five nines (99.999%) availability and cannot be teared down without causing major disruptions.