[RADIATOR] [Radiator] SCTP Multihoming

[Heikki Vatiainen]

On 21.11.2017 17:30, Trey Ormsbee wrote:
> Does Radiator support SCTP Multihoming?

Radiator uses the same socket interface calls for TCP and SCTP. This 
means the multihoming capability is limited to what can be achieved 
without SCTP specific calls. For example, if you see SCTP sockets API 
and search for 'multi-' you'll see that multi-homing is automatically 
enabled for some cases.

https://tools.ietf.org/html/rfc6458

There's one SCTP specific configuration option in Radiator that helps 
with multihoming. You can specify multiple peers with SCTPPeer and 
Radiator will try to connect to each of them with connect() until it 
succeeds. This could also be used later to set the hosts for 
sctp_connectx() when this SCTP specific call is available.

This is not as good as sctp_connectx() since it means calling connect() 
in serial instead of handing all hosts to sctp_connectx(), but while it 
may take longer, it should still get the connection up if there's at 
least one destination address that responds.

> The only thing I see in the documentation regarding multihoming is is
> for binding across multiple ip's. But nothing specific for sctp
> multihoming.

Looks like SCTPPeer is not documented, but that is available for 
Diameter and other Stream based classes.

We have thought about creating the necessary bindings for the SCTP 
socket calls. When this happens has not been decided yet, and it depends 
on, for example, how much need there would be for the SCTP specific 
socket calls and options.

Thanks,
Heikki

-- 
Heikki Vatiainen
hvn at open.com.au