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Re: T1 bonding

  • From: Elijah Savage
  • Date: Tue Jan 24 20:22:05 2006

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Scott Morris wrote:
> If you're treating them as two separate links (e.g. two POPs, etc.) then
> that's correct, it'll be done by the routers choice of load-balancing (L3).
> If you are going to the same POP (or box potentially) you can do MLPPP and
> have a more effective L2 load balancing.
> 
> Otherwise, it's possible to get an iMux DSU (Digital Link is a vendor as I
> recall, but there may be others) that allow that magical bonding to occur
> prior to the router seeing the link.  At that point, the router just sees a
> bigger line coming in (some do 6xT-1 and have a 10meg ethernet output to
> your router).
> 
> If you're seeing the balancing the way that you are, most likely that vendor
> (I have no specific knowledge about the A-vendor) is doing usage-based
> aggregation which isn't exactly a balancing act.  The ones at some of my
> sites are MLPPP which is a vendor-agnostic approach for the most part.
> 
> Scott 
> 
> -----Original Message-----
> From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of
> Elijah Savage
> Sent: Tuesday, January 24, 2006 7:28 PM
> To: Matt Bazan
> Cc: nanog@merit.edu
> Subject: Re: T1 bonding
> 
> 
> Matt Bazan wrote:
>>> Can someone shed some technical light on the details of how two T1's 
>>> are bonded (typically).  We've got two sets of T's at two different 
>>> location with vendor 'X' (name starts w/ an 'A') and it appears that 
>>> we're really only getting about 1 full T's worth of bandwidth and 
>>> maybe 20% of the second.
>>>
>>> Seems like they're bonded perhaps using destination IP?  It's a vendor 
>>> managed solution and I need to get some answers faster than they're 
>>> coming in.  Thanks.
>>>
>>>   Matt
>>>
> More than likely they are not bonded t1's they are just load balanced by the
> router which by default on Cisco is per session. Meaning pc1 to t1#1, pc2to
> t1#2, pc3 to t1#1. If they are truly bonded with some sort of MUX for a 3
> meg port then you would not see the results you are seeing.
> 
> --
> http://www.digitalrage.org/
> The Information Technology News Center
Remember he said both t1's are coming from different vendors, which
would only leave the Mux route which is why I said what I said :)
- --
http://www.digitalrage.org/
The Information Technology News Center
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