[AVTCORE] Proposed text for draft-ietf-avtcore-ports-for-ucast-mcast-rtp-01

["Ali C. Begen (abegen)" <[e-mail]>]

Based on a comment from IESG, we would like to propose the following change to the Token draft. It is about increasing the length of the Tokens. Currently, the length field is 1 byte, IESG recommends 2 bytes with a warning sign.

Please let us know if you do not want this change. 
Link to the draft: https://datatracker.ietf.org/doc/draft-ietf-avtcore-ports-for-ucast-mcast-rtp/?include_text=1

-acbegen

New text for 4.2

Token Element (Variable size): Element that is used to carry the Token generated by the server. This element is a 32-bit aligned Length-Value element. The Length field, which is 16 bits, indicates the length (in octets) of the Value field that follows the Length field. While a 16-bit length allows for Tokens with a size of up to 65535 bytes, using Tokens larger than 1000 bytes is generally a bad idea since this can easily cause IP fragmentation. Note that a Token has to be transmitted in an RTCP compound packet within a UDP packet, which often has an MTU of 1500 bytes.
 
The length does not include any padding that is required for alignment. The Value field carries the Token (or more accurately, the output of the encoding process on the server). If the Token element does not fall on a 32-bit boundary, the last word MUST be padded to the boundary using further bits set to zero.