Cox clamping VPN traffic?

Tomas L. Byrnes tomb at byrneit.net
Sat Jan 26 01:27:03 UTC 2008


The throttling I am talking about occurred on business class service
which is rated at 16Mbps/2Mbps and is NOT cheap. I'd love to know what
the throttling mechanism Comcast uses is, as Cox swears up and down that
they have no such thing in place. That both got throttled to the EXACT
SAME, non multiple of a DS0, is just a bit too coincidental for me.

If it was some sort of trunk capacity or mux issue, I would expect the
BW I was left with to be a multiple of 64Kbps or 1.544 Mbps, not some
odd-ball number like 43Kbps.

 

> -----Original Message-----
> From: Jim Popovitch [mailto:yahoo at jimpop.com] 
> Sent: Friday, January 25, 2008 4:50 PM
> To: Tomas L. Byrnes
> Cc: nanog at nanog.org
> Subject: Re: Cox clamping VPN traffic?
> 
> On Jan 25, 2008 12:17 PM, Tomas L. Byrnes <tomb at byrneit.net> wrote:
> >
> >
> > I've got a local peer with Cox for VPN users to co-lo. A VPN 
> > connection that otherwise shows no issues just had their 
> file transfer 
> > rate during a large file transfer over the VPN go from 10Mbps to 
> > 43kbps, and stay there. This isn't transit, it's local peering.
> 
> I see the *exact* same problem with Comcast at home.  I get 
> about 30 seconds of the 6.6Mbps provisioned rate then the 
> drop kicks in and down to 43kbps it goes.  In talking with 
> Comcast engineers privately, I've learned that the 
> "provisioned" rates should no longer be
> considered as sustainable, only initial.   Now I don't normally need a
> sustained up/down rate, but it has come in handy in the past 
> when up/down-loading backups or ISOs... but I guess those 
> days are behind us as the large providers have started 
> re-interpreting the definition of "provisioned", or to be 
> more accurate they have implemented a TTL on it.  That said, 
> I do see their point of view wrt PTP, esp torrent traffic, 
> and their desire to limit it's impact on their networks....
> but it does boil my blood when *I* need to use "my" bandwidth for
> legitimate purposes only to find myself throttled. :-)   Part of me
> wonders if this isn't an effort to push "business" class services.
> 
> -Jim P.
> 



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