Cell Relay Archive

[spork_neck@yahoo.com (Dan)]

"E. C. Meggison" <emegg@bellsouth.net> wrote in message news:<7eE48.96551$Ee7.6403611@e3500-atl1.usenetserver.com>...
> "Thomas Frieling" <thomas.frieling@arcor.de> wrote in message
> 3C52D71F.7FAB88A6@arcor.de">news:3C52D71F.7FAB88A6@arcor.de...
> >
> > Dan schrieb:
> > >
> > > (...)
> > >  Each pvc is config'ed for 6 meg vbr-nrt. (...)
> >
> > Is this PCR or SCR? And how about MBS? Or is this a traffic
> > shaping parameter at the routers?
> > Anyway. The traffic shaping settings at the routers have to match
> > the UPC-settings at the ATM-network. If the routers allow only a
> > PCR traffic shaping cells are discarded by the network during
> > peaks which exceed MBS...
> 
> ...or Sustained cell rate.  MBS only limits the number of cells that can be
> sent at the peak cell rate.
> 
> > If your ATM-network switches allow the choice of the VBR.3
> > conformance definition this will probably solve or mitigate your
> > problem. VBR.3 allows the traffic source to exceed the Maximum
> > Burst Size and cells in excess of MBS will be transported on a
> > best effort base.
> 
> Better known as tagging.  However, these cells are discard eligible.
> 
> >
> > Thomas

Thanks for the replys so far,

Included below are partial configs from our central router and 1
remote router.

NOTE: We can achieve out full SCR and even PCR if we increase our TCP
window size on our Windows/9x/NT/2000 boxes. (unix/linux need no
adjustment)

Again, my question is is this the only way to achieve our SCR across
the ATM network? By adjusting TCP window size? What is it about ATM
the creates the need for such an adjustment? We were fine with Frame
Relay with similar bandwidth and delay.

Thanks again!



Central Site ATM config
--snip--
!
interface ATM1/0
 no ip address
 load-interval 30
 atm scrambling cell-payload
 atm framing cbitplcp
 no atm ilmi-keepalive
!
interface ATM1/0.11 point-to-point
 description Miramar PVC
 ip address 10.96.1.21 255.255.255.252
 pvc miramar 11/32
  protocol ip 10.96.1.22 broadcast
  vbr-nrt 6173 4115 100
  encapsulation aal5snap
 !
!

remote site atm config

--snip--
!
interface ATM1/0
 no ip address
 load-interval 30
 atm scrambling cell-payload
 no atm ilmi-keepalive
!
interface ATM1/0.1 point-to-point
 ip address 10.96.1.22 255.255.255.252
 pvc miramar 11/32
  protocol ip 10.96.1.21 broadcast
  vbr-nrt 6173 4115 100
  encapsulation aal5snap
 !
!