3 ms·

I'd like to also add to this that SCTP doesn't ship on Mac OS X either by default. Although, in recent years there have been development on an SCTP over UDP sta

by sargun 11y ago

I'd like to also add to this that SCTP doesn't ship on Mac OS X either by default. Although, in recent years there have been development on an SCTP over UDP standard, allowing for user-mode SCTP. Yet, I still haven't seen a mature version of this API ship on Mac OS X. Some time ago, I also did performance testing on SCTP vs. TCP. It's surprisingly sad how much worse SCTP's performance was compared to TCP. I imagine that this is because just isn't as much work put into SCTP as TCP.

elihu 11y ago
SCTP uses 32 bit checksums rather than 16. It may be the case that your hardware can do 16 bit checksums in hardware, but for SCTP it has to do the checksum in software. (I think it used to be the case and maybe still is that SCTP vs TCP benchmarks would disable hardware checksums so that the results weren't biased unfairly in favor of TCP.)
- throwaway2048 11y ago
  even at gigabit speeds, unless the implementation is really, really bad, checksumming will absolutely not be the issue here as far as my experience goes. Benchmarks should be consulted before preformance issues are debated.
  - MrBuddyCasino 11y ago
    I once made a CRC64 implementation, and single core performance was at 1150 MBytes/s on Java 8. So, yeah.
- pktgen 11y ago
  Some Intel NICs (at least the 10G ones, but some Googling suggests some 1G as well) support SCTP checksum offload. Also, the checksum is a CRC32C and the SSE4.2 CRC32 instruction can calculate these really fast.