SNC and TLS - How much impact on performance and network traffic?

[Colt]

In my trainings, I often got questions about the impact of SNC and/or TLS encryption. The usage of SNC for DIAG and RFC communication results in a higher CPU consumption thus a performance impact.

However, we know due to today's CPUs and connection speeds, performance problems are barely noticeable. I remember poorly connected field offices (ISDN) which had more disconnections when enabling the SNC / TLS encryption. But these times are long gone.

Nevertheless, it would be helpful if there were already investigations about what impact SNC (QoP 3) brings on CPU / system performance and network (traffic, latency-times…). With SNC DIAG and RFC are encapsulated at the network level within SNC frames, and thus the protocol stack will certainly have a larger overhead compared to plain DIAG / RFC. Are there reliable numbers for this?

I have a vague idea of reading the %-impact on performance, especially CPU and network traffic increase once "somewhere". For reliable sources of information, preferably from SAP itself, many customers and I would certainly be very grateful! 🙂

[Colt]

UPDATE: Maybe someone is interested 🙂

• Found SAP Note 1043694 - Performance impact when using SNC for SSO
• Extract see below. Another interesting page here
• Unfortunately either the links in this page nor in the SAP Note specified above are working. I've found a working FTP server containing the gss-test suite and other useful (but older) stuff here.

SAP does not make any recommendations for the choice of one particular BC-SNC certified solution over another. The performance measurements collected by SAP's tool "gsstest" during BC-SNC certification are not published and they are of very limited use to make an estimate on the performance impact of specific usage scenarios (or application benchmarks). It is up to the vendors of the security solutions to provide 
performance figures.

The GSSTEST tool used by SAP for BC-SNC certification and checking of
interoperability constraints is available for public download as Open 
Source from the Web-Page containing the BC-SNC certification info