Question on peering strategies

Marty Strong marty at
Mon May 23 18:19:03 UTC 2016

The usefulness of an elastic fabric as far as I can see it are:

- Can give you a private VLAN to some *cloud* providers that provide direct access to them in some other fashion than peering (assumedly for enterprises)
- Is spread across multiple buildings across a metro area
- Is elastic so can be divided between different services for different time periods

In a traditional peering sense it doesn’t really offer much value.

Just my two pence.

Marty Strong
CloudFlare - AS13335
Network Engineer
marty at
+44 7584 906 055
smartflare (Skype)

> On 23 May 2016, at 18:53, Reza Motamedi <motamedi at> wrote:
> 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
> peering
> • *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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