Below are the steps involved:
1. Fragmentation: Every upper layer message is fragmented into 2^14 equivalent to 16384
bytes or less blocks.
2. Compression: This one is optionally
applied and must be lossless. It may not increase content length by more than
1024 bytes.
3. Compute a MAC (Message Authentication
Code): For this purpose, a shared secret key has to be used.
4. Encryption: Inclusive of the MAC, the
compressed message is encrypted using symmetric encryption. It must not
increase the length by 1024 bytes or more.
5. Preparing a heading in the following
fields: Major Version (8 bits); Compression Length (16 bits); Minor Version (8
bits); and Content Type (8 bits).
