On Tue, Sep 7, 2010 at 11:48 PM, Fred Baker <[email protected]> wrote: > > On Sep 8, 2010, at 11:44 AM, Christopher Morrow wrote: > >> On Tue, Sep 7, 2010 at 9:18 PM, Brian E Carpenter >>> If this is correct, it is futile to assert that the flow label >>> MUST be delivered unchanged to the destination, because we >>> cannot rely on this in the real world. >>> > > Anything that cannot be proven to have the same original value at the end of > the ride has this characteristic.
seems like a fine idea. >>> Are we ready to accept this analysis? > > I, personally, am very ready to accept this analysis. It might be key to > making the flow label useful. > >> what's the threat if it changes in flight? multiple times even? > > Speaking for myself, I see no threat. On the other hand, the question to me > is what might be the benefit. What has been proposed is some variation on a > load-sharing hash, one that might, for example, let the ingress node in a > network direct specified traffic streams to one of several egresses - > essentially what is done using MPLS but without the fuss and bother. > > One could imagine this being something akin to an ECMP route, but without any > real discussion of "routing cost". Imagine that we could assign egress > numbers to routers - akin to an IP address, but fits in 20 bits. An ingress > node could look at some tuple (source/destination address, DSCP, whatever > else) and decide that the correct egress router is <something>, and put the > <something>'s number in the flow label to direct traffic towards the egress. > One could imagine several policies - traffic toward a given egress is up to > some limit rate, and arriving traffic that exceeds that rate goes to a > different egress for example, or 1/3 of sessions this way and 2/3 that, or > whatever served the ISP. this all gets 'crazy', I suppose if we wanted to route on flow-label not destination-ip-address this might happen, but ... that seems 'crazy' as I said before :) since not everyone would be using the flow-label (maybe) and inconsistent routing would suddenly make the internet look a lot like a PSTN network (to me). 'crazy' I say!! -chris -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
