First, recently returned to the CIP protocol and then query the data and found that MIME (Multipurpose Internet Mail Extensions) need to know about. (Multipurpose Internet Mail Extensions type)
Directly related literature is "Multipurpose Internet Mail Extensions (MIME) Part One: the Format of Internet the Message Bodies", RFC 2045 , November 1996 RFC is the specification of the protocol text
Below understand CIP Common Industrial Protocol design-related documentation (the focus of several protocols yellow marker)
[RFC 2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [RFC 2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [RFC 2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., Leach, P., Luotonen, A. and L. Stewart, "HTTP Authentication: Basic and Digest Access Authentication", RFC 2617, June 1999. [CIP-ARCH] Allen, J. and M. Mealling, "The Architecture of the Common Indexing Protocol (CIP)", RFC 2651, August 1999. [CIP-MIME] Allen, J. and M. Mealling, "MIME Object Definitions for the Common Indexing Protocol (CIP)", RFC 2652, August 1999. [ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [CIP-TIO] Hedberg, R., Greenblatt, B., Moats, R. and M. Wahl, "A Tagged Index Object for use in the Common Indexing Protocol", RFC 2654, August 1999. [KEYWORDS] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[MIME-SEC] Galvin, J., Murphy, S., Crocker, S. and N. Freed,
"Security Multiparts for MIME: Multipart/Signed and
Multipart/Encrypted", RFC 1847, October 1995.
[MHREG] Jacob, P., "Mail and Netnews Header Registration
Procedure", Work in Progress.
二、RFC CIP 梳理的要点
CIP SEcurity secure the safety of the transport data and the MIME Object, but security is dependent on the transmission of data to complete the TLS, the ultimate aim is to be discussed with TLS security issues.