Question on peering strategies

Reza Motamedi motamedi at
Mon May 23 17:53:58 UTC 2016

I'm glad we are having this discussion.

I want to clarify something, since I'm not sure I'm following the
terminology. What Max referred to as  "VLAN exchange" is what Equinix
markets as "*private VLAN"*, right?
I just copy-pasted a portion of Equinix's IX brochure that covers the
services that they offer []
Standard Equinix Internet Exchange Features
• Public VLAN — offers access to all peering participants
• Supports industry standard IEEE 802.1Q trunking encapsulation
• Redundant MLPE route servers at each IX Point enabling efficient open
• *Private VLAN* (Required: Unicast Peering VLAN enabled) — create a
private broadcast domain over the public switched infrastructure that can
be used for direct bi-lateral peering or to create a community of interest

My question is what is the point of having such an option for peering? I
understand the argument that Owen and Leo have, which is to move the bigger
portion of traffic away from the IX fabric and keep the IX for smaller
flows. but why would a pair of networks want a private point-to-point
connection on a shared switching fabric. Is this just because that shared
fabric has geographical reach, as in the case of IXReach?

I also see that links provided in this discussion show Europe based
networks that are using this peering type more often. Is this widely
accepted that US market is totally different from Europe?

Best Regards
Reza Motamedi (R.M)
Graduate Research Fellow
Oregon Network Research Group
Computer and Information Science
University of Oregon

On Mon, May 23, 2016 at 9:50 AM, Owen DeLong <owen at> wrote:

> As mentioned by others, they do exist, but usually not for exactly the
> reason you state.
> In most cases, peers go to PNI instead of peering via the exchange when it
> does not make
> sense to grow laterally at the exchange for significant bilateral traffic.
> It’s much
> less expensive to get a cross-connect from my router to your router than
> for both of
> us to add a cross-connect to the exchange and each pay for an additional
> exchange port.
> Example: If I have 12.5 gigs of traffic to the exchange and 8 gigs of that
> is to
> autonomous system X while the remaining 4.5 G goes to random other peers,
> then it
> makes much more sense for both X and I to connect directly (PNI) than for
> each of
> us to order an additional exchange port to support that traffic.
> Owen
> > On May 21, 2016, at 23:33 , Max Tulyev <maxtul at> wrote:
> >
> > Hi All,
> >
> > I wonder why a "VLAN exchange" does not exists. Or I do not know any?
> >
> > In my understanding it should be a switch, and people connected can
> > easily order a private VLAN between each other (or to private group)
> > through some kind of web interface.
> >
> > That should be a more easy and much less expensive way for private
> > interconnects than direct wires.
> >
> > On 16.05.16 20:46, Reza Motamedi wrote:
> >> Dear Nanogers,
> >>
> >> I have a question about common/best network interconnection practices.
> >> Assume that two networks (let's refer to them as AS-a and AS-b) are
> present
> >> in a colocation facility say Equinix LA. As many of you know, Equininx
> runs
> >> an IXP in LA as well. So AS-as and AS-b can interconnct
> >> 1) using private cross-connect
> >> 2) through the public IXP's switching fabric.
> >> Is it a common/good practice for the two networks to establish
> connections
> >> both through the IXP and also using a private cross-connect?
> >>
> >> I was thinking considering the cost of cross-connects (my understanding
> is
> >> that the colocation provider charges the customers for each
> cross-connect
> >> in addition to the rent of the rack or cage or whatever), it would not
> be
> >> economically reasonable to have both. Although, if the cross-connect is
> the
> >> primary method of interconnection, and the IXP provides a router-server
> the
> >> public-peering over IXP would essentially be free. So it might makes
> sense
> >> to assume that for the private cross-connect, there exists a back-up
> >> connection though the IXP. Anyway, I guess some discussion may give more
> >> insight about which one is more reasonable to assume and do.
> >>
> >> Now my last question is that if the two connections exist (one private
> >> cross-connect and another back-up through the IXP), what are the chances
> >> that periodically launched traceroutes that pass the inter-AS
> connection in
> >> that colo see both types of connection in a week. I guess what I'm
> asking
> >> is how often back-up routes are taken? Can the networks do load
> balancing
> >> on the two connection and essentially use them as primary routes?
> >>
> >> Best Regards
> >> Reza Motamedi (R.M)
> >> Graduate Research Fellow
> >> Oregon Network Research Group
> >> Computer and Information Science
> >> University of Oregon
> >>

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