Cisco PPP DS-3 limitations - 42.9Mbpbs?

Wed Feb 20 20:38:08 UTC 2002

OMG! Arent we missing the point here? What about never running links above 
60% or so to allow for bursts against the 5 min average, and <shudder> 
upgrading or adding capacity when we get too little headroom.

And here we are, nickel and diming over a few MBps near to 45M on a DS3...
....

Or has the world changed so much that saturated pipes are The Way Things 
Are TM now.

jm

On Wednesday, February 20, 2002, at 09:37 AM, Alex Rubenstein wrote:

>
>
> BTW:
>
>   30 second input rate 13039000 bits/sec, 8055 packets/sec
>   30 second output rate 45531000 bits/sec, 10021 packets/sec
>
> Thats a pa-2t3+ on a flexwan in a 6509.
>
>
>
> On Wed, 20 Feb 2002, Stephen J. Wilcox wrote:
>
>>
>> Hmm, reasonable explanation..
>>
>> presumably this can be improved (a little) with increased interface
>> buffers.. ? and possibly non fifo queuing eg custom queuing in favour of
>> TCP rathen than UDP/ICMP etc which wont have the backoffs
>>
>> Cheers
>>
>> Steve
>>
>> On Wed, 20 Feb 2002, Randy Bush wrote:
>>
>>>> we run HDLC on DS3 and we max at about 40.something too
>>>
>>> if you're using five min (or three min) samples, and you're seeing 70%,
>>> peaks are likely much higher and some users' packets are being dropped.
>>> by 80%, enough packets are being dropped that users are likely to see
>>> the effects of exponential backoff.  things do not improve above 80%.
>>>
>>> randy
>>>
>>
>> --
>> Stephen J. Wilcox
>> IP Services Manager, Opal Telecom
>> http://www.opaltelecom.co.uk/
>> Tel: 0161 222 2000
>> Fax: 0161 222 2008
>>
>>
>
> -- Alex Rubenstein, AR97, K2AHR, alex at nac.net, latency, Al Reuben --
> --    Net Access Corporation, 800-NET-ME-36, http://www.nac.net   --
>