Linux-ATM support.

[Charles R. Anderson]

On Sat, Jul 31, 2004 at 12:46:53PM -0400, Lamar Owen wrote:
> So ATM features are more Enterprise than hobbyist, but having robust ATM 
> networking for CLIP over PVC and SVC as well as LANE support could raise some 
> interest in high-bandwidth applications.  

ATM is still too overly complex as an Enterprise networking
technology.  Certainly support should be there for those who need it,
but I doubt it is worth the effort just for new high-bandwidth
applications, unless the intent is to work with legacy ATM
infrastructure.

> In my case, the server that the HE card is in needs to associate with multiple 
> ELANS for firewall and routing purposes; ATM NIC's are great for that sort of 
> thing, since I can set up a CLIP VC and two or more LEC's on the one card; 
> but as far as the kernel is concerned they are physically separate 'ethernet' 
> interfaces.

Ethernet can do that with 802.1Q VLANs.  I just don't see the
advantage of ATM for new deployments in this case.  Emulating
broadcast LANs on top of circuit-switched technology is inefficient,
complex, and fragile.  On the other hand, the support could be useful
for those stuck with legacy ATM in order to create firewalls, IDS's,
flow analysis tools, etc.

> The problem ATM has faced in the past is a combination of cost and complexity.  
> Cost is going down, and enterprise-class switches routinely turn up on eBay 
> at a fraction of their retail cost (hrmph, I've seen several Nexabit NX64000 
[...]
> five-switch fully redundant ATM network with multiple ELANS and LECS/LES/BUS 
> automatic failover in just a few months (and, while my title is IT Director, 
> I am basically the entire IT department, and do everything from terminating 
> fibers to writing software).  It just wasn't that hard.

Ugh.  It seems silly to create all that complexity just to work around
the inherent weaknesses of the LANE technology, with all the overhead
to boot.  I don't think you characterize the average IT person.

> And it impresses people to no end when I physically pull an OC-12
> trunk fiber out of a switch port and the switch transparently
> reroutes over the other fibers....

Ethernet can do that too with 802.3ad Link Aggregation.  I too went
through my ATM phase and I'm much happier now that I have migrated to
a completely Ethernet infrastructure.