Question about peering

Thu May 10 00:06:37 UTC 2012

Most of the time no.  ISP A and ISP C probably don't have alot of traffic
destined for each other's AS's.  Without other peers in an IX sort of model
the link would probably be mostly devoid of (useful) traffic. Although, if
ISP A and C were small regional ISP's and they could get free peering from
someone like netflix that may be worth while, but I digress.   Another
interesting occurrence would be if ISP A shifted it's metrics to force it's
transit traffic into ISP C's AS offloading the cost of the eventual ISP B
hop to ISP C. (assuming someone announces the full table)  I've also seen
ISP A re-announce ISP C's routes to their upstreams with preferred metrics
in order to make the link "one-sided" and begin billing ISP A.

2012/4/6 Anurag Bhatia <me at anuragbhatia.com>

> Hello everyone
>
>
>
> I am curious to know how small ISPs plan peering with other interested
> parties. E.g if ISP A is connected to ISP C via big backbone ISP B, and say
> A and C both have open peering policy and assuming the exist in same
> exchange or nearby. Now at this point is there is any "minimum bandwidth"
> considerations? Say if A and C have 1Gbps + of flowing traffic - very
> likely peering would be good idea to save transit costs to B. But if A and
> C have very low levels - does it still makes sense? Does peering costs
> anything if ISPs are in same exchange? Does at low traffic level it makes
> more sense to keep on reaching other ISPs via big transit provider?
>
>
>
> Thanks.
>
> --
>
> Anurag Bhatia
> anuragbhatia.com
> or simply - http://[2001:470:26:78f::5] if you are on IPv6 connected
> network!
>
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