North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: ATM (was Re: too many routes)

  • From: Richard Irving
  • Date: Mon Sep 15 19:13:20 1997

Peter Kline wrote:
> 
> 
  Hey Peter,

     Long time no see (a couple years at least)! 
I remember now you became a "Golden Handcuff" kid. How are you liking
Cisco ?

     This thread has become a Holy war, I quit responding when some of
our "esteemed" colleague's started 
resorting to "ad homonym" Arguments.( ie. ATM doesn't work 'cause your
UGLY! ;{ )  But, for you.... :)

     The BPX has the capability to understand the advantage of multiple
paths, and capitalize on them. Kind of 
a DEC spanning tree instead of an IEEE. (I just thought I would confuse
everyone again ;)

     Certainly the easiest way to configure this is to simply manually
load balance the PVC's based upon 
expectation, then it looks like:

        trunk or uni
       uni /DS3\   uni
    OC3-OC3-DS3-OC3->OC3
           \DS3/

     Now manually, this can be done on any vendor combo that
interoperates. The downside, it won't be dynamic,
and there is no way to ever get a PVC or SVC > 45mbs. You also need to
know ahead of time what the utilization 
will be, and it cannot adjust. So if two SVC's burst at the same time,
ooops.

     With ForeSight, the physical looks the same, except now the DS3's
must be Trunks. However, the VC's can 
now be bundled or grouped, etc. This makes the path that any one
connection takes dynamic,
selecting one of the DS3 trunks. This is an "on the fly operation". It
will adjust according to each VC's
need, and each trunks load (with preference for re-using the same trunk
if possible). It will also re-route to
react to "real-time" requirements/bursts. So, if two vc's burst, they
will retrain to different trunk paths, 
(if needed , of course...) auto-magically. 

   Don't the guys on the Strat side of the shop talk to you guys ? ;)

Richard

**
 "Real-Time" is defined, in this case, as "As soon as it notices, it
will change as fast as it can"
 "DEC spanning tree vs IEEE is for the purpose of ANALOGY only, not a
direct,exact,precise,perfect identical
  comparison, (Those who cannot see the forest for the tree's..., go
into management! Just think,
  you will get to wear a tie everyday, and dress so nice that it will
instantly be obvious to you that all 
  the geeks in blue jeans are inferior. You can *then* have the sense of
security that all these confusing 
  technical terms seem to be undermining in you....;)"
> 
> -peter