Subject: AW: your mail

From: Hummel Heinrich <[email-masked]>
Date: Mon, 1 Jul 2002 14:47:46 +0200

1)
Venkata wrote to Neil:

  As I said before, whether to do load balancing or not 
  is _not_ an interoperability issue. It's the best interest
  of any vendor. No *specification* required - *requirements*
  may be sufficient.

I completely disagree. It takes a lot of common specification to enable load balancing capable
IP routing. Honestly, I believe it would take a new working group to do that.

2) Can anybody explain to me why Equal-Cost Multipath and why not simply Multipath ? 
For traffic balancing you may need alternatively routed pathes (MPLS-pathes, IP-pathes) which
arent necessarily of equal cost, right ?

Heinrich Hummel

Siemens

---

From: Eric Osborne <[email-masked]>
Date: Mon, 1 Jul 2002 09:57:09 -0400

On Mon, Jul 01, 2002 at 02:47:46PM +0200, Hummel Heinrich wrote:
> I completely disagree. It takes a lot of common specification to
> enable load balancing capable IP routing. Honestly, I believe it
> would take a new working group to do that.

OK, now I'm confused.  I suspect that your definition of "load
balancing" is different than mine, as I believe that both IP and LDP
are capable of load-balancing.  Some folks have said that LDP is not
capable of such a thing, but this is the first time I've heard anyone
say that IP can't do it, either.  What exactly does "load balancing"
mean to you?

> 2) Can anybody explain to me why Equal-Cost Multipath and why not
> simply Multipath ?  For traffic balancing you may need alternatively
> routed pathes (MPLS-pathes, IP-pathes) which arent necessarily of
> equal cost, right ?

With IP, you can end up with permanent loops if you don't provision
equal-cost forwarding properly.  That's why IP (and LDP, which I've
always viewed as more of an arp-like thing under IP, in this
instances) only do equal-cost balancing.  TE has the advantage that it
can use MPLS to assure a loop-free path from head to tail of a tunnel,
so it can do more complex balancing at the headend, i.e. unequal cost
placement of traffic into tunnels.

At least that's how I look at it.

eric