SCTP guidelines for Diameter base protocol specified in section 2.1.1 of RFC 6733

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I have a query on SCTP guidelines for Diameter base protocol specified in section 2.1.1 of RFC 6733 as :

"A Diameter agent SHOULD use dedicated payload protocol identifiers (PPIDs) for clear text and encrypted SCTP DATA chunks instead of only using the unspecified payload protocol identifier (value 0). For this purpose, two PPID values are allocated: the PPID value 46 is for Diameter messages in clear text SCTP DATA chunks, and the PPID value 47 is for Diameter messages in protected DTLS/SCTP DATA chunks."

RFC doesn't specify the behavior if the connected diameter peer doesn't use PPID as 46/47 for diameter message transport over SCTP or DTLS/SCTP. What if diameter messages are received with PPID set to value other than 46/47 or default 0 value? Should the messages be ignored or respond with error diameter message back to peer with same PPID set ? Please comment on this behavior.

posted Aug 23, 2013 by Mandeep Sehgal

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1 Answer

I think the correct behavior would be to discard the data and close the connection, but since this is new in 6733, I haven't seen actual implementations doing this.
Though 3GPP specs insist on SCTP, most implementations on the field seem to be TCP based.

answer Aug 26, 2013 by Rathnakumar Kayyar

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