On 06.03.2003 at 08:37:49, Rob van der Heij <[EMAIL PROTECTED]> wrote:
> Our CPU's are too expensive to be bothered with ARP... I rather offload this > work to the OSA card. Ok, so lets keep all the good ARP processing etc, and unload all the other stuff. ;-) > I recall from tests that the cost of getting all broadcast traffic on a > moderately quiet LAN was about 5 times the cost of the 100 Hz timer tick. > Go figure what would happen if OSA would copy the packets to everyone. Granted, the processing of broadcast frames is not too attractive. But the copying of all the frames to everyone is definitely not cool. So we don't do it. The thing that makes Adam's RTL8139 simple is the fact it doesn't need to have multiple "systems" using it (ok, and the fact that on a PC we don't care about the overhead of ARP, but let's forget that a moment). This is exactly what makes an OSA complicated. So maybe IBM should give us an OSA that can't do EMIF, but still does the ARP Offload and other stuff that we like (thank you IBM). Better still (and zero cost to IBM), perhaps we should not share our OSAs with any other systems. Dedicate the CHPIDs to your z/VM LPAR (reconfigurable, perhaps, but not shared). You may find that your scaredy z/OS network guys (we're not that bad, Adam, really) would prefer it that way, and to be honest, on top of what you've already paid for IFLs, DASD, support, 3rd party software, etc, another couple of OSA ports doesn't add *too* much. However, if sharing is what we want, we have to accept that it comes at a cost. If that cost is a few z/OS network sysprogs getting beaten about the head (I'll admit, Adam, that we can be stubborn sometimes ;-) ) in order for them to let go of "primary router" -- which we all know there is no need for z/OS to have -- then so be it. > And I don't want the penguins to waste time discussing routing amongst > themselves when there is only one way out anyway. If some more work is > needed for routing, then I want one virtual machine to do that for all. Absolutely. He's the router penguin that owns the OSA port (one penguin to rule them all -- sorry, couldn't resist: been in NZ too long). Can someone remind me what the PORTNAME is actually for, again? Cheers, Vic Cross
