Describes problems and solutions for load-balaning with multihomed SCTP.
It is essential that all paths of an association ends up in the same backend (server).
For a multihomed SCTP association the addresses (both source and dest)
are different for the paths but the ports are always the same. So
for SCTP the nfqlb hash on ports only. Another possibility is to use
IPv6 and the flow label. This is not yet implemented though.
The properties, such as scalability, are the same as for tcp/udp but distribution will basically be based the on source port (since the dest (server) port is the same).
DSR should be used since NAT can not be used without great difficulties. From rfc3257;
the NAT can have internal Application Layer Gateway (ALG) which will intelligently translate the IP addresses in the INIT and INIT ACK chunks
For SCTP over UDP hashing is still made of the SCTP ports. The
encapsulation (UDP) port is specified with the --sctp_encap=9899
option to nfqlb. If a UDP packet with the specified port as
destination port arrives, hashing is made on the SCTP ports.
