Re: SCTP failover

From: David Lehmann <lehmann@ulticom.com>
Date: Fri Feb 11 2005 - 14:08:35 EST

('binary' encoding is not supported, stored as-is) ('binary' encoding is not supported, stored as-is) Randall Stewart wrote:
> In any event the only way to keep the network failover time
> down is to set RTO.Max to a lower value.. that would make things
> faster... To have a 1 second failover I would imagine that
> Ulticom's stack is setting both RTO.Min and RTO.Max to a
> lower value... aka that adds up to a total of 1 second..
> I.e. something like 50ms RTO.Min and 400ms RTO.Max

Nope. When the error count is greater than 0 on the
primary destination, Ulticom uses an alternate destination,
until the error is cleared on the primary destination.
So, if the user is using the default values, the user
will only see a blip for one second.
(...assuming an RTO of 1 second)

IMHO, waiting around for 1 minute while data trickles through
the association is not acceptable and does not give the user
of a sense of transparent network redundancy.

IMHO, the language in section 6.4 should be changed from:
    By default, an endpoint SHOULD always transmit to the primary path,
    unless the SCTP user explicitly specifies the destination transport
    address (and possibly source transport address) to use.
to something like:
    By default, an endpoint SHOULD always transmit to the primary path,
    unless the error count on the destination is greater than zero or the
    SCTP user explicitly specifies the destination transport address (and
    possibly source transport address) to use.

-- 
David Lehmann                          Ulticom, Inc.
AOL/Yahoo IM: davidULCM                1020 Briggs Road
1-856-787-2729                         Mt. Laurel, NJ 08054   USA

Received on Fri Feb 11 14:31:49 2005