Internet Exchanges L1-L7

Internet Exchanges — 7 vendors and operators, each broken down by layer L1 to L7: what they sell at that layer, and which layer is their home turf.

DE-CIX

Home turf: L1 / L2

L1 Physical

This is one of this domain's star layers. An IXP's physical-layer product is remarkably plain: a switch port, plus a fibre patch cable (cross-connect) running from the participant's own rack to that port.

L2 Data Link

This layer is the IXP itself — what it sells sits exactly here in the protocol stack. An IXP provides a shared layer-2 switching fabric: every participant's port hangs in the same broadcast domain, able to communicate directly by MAC address as though on one local network, and on top of that layer-2 plane each pair establishes layer-3 peering sessions (see L…

L3 Network

This layer is where participants actually do business on an IXP. The IXP assigns a public IP subnet to the fabric, each participant takes one address, and they establish BGP sessions within that subnet to exchange routes.

L4 Transport

This layer is explicitly empty — no product or service. An IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange; it does not terminate, proxy or optimise participants' transport-layer connections, and TCP and UDP traffic crossing the fabric is entirely transparent payload to it.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (already recorded at L3), and the portal members use for self-service management is an application-layer matter (see L7), neither constituting an independent session-layer product line.

L6 Presentation

This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product. One reality deserves stating honestly here: an IXP fabric does not itself encrypt the traffic crossing it, and confidentiality between participants is each party's own responsibility (for instance running encrypted tunnels over it o…

L7 Application

This layer is this domain's operational and value-added interface. The base part is the member portal and traffic statistics: viewing your port's real-time and historical traffic, peering far-end lists, billing and tickets — and those traffic statistics are the direct basis on which a participant judges whether an IXP remains worth the investment, because th…

AMS-IX

Home turf: L2 / L3

L1 Physical

The physical-layer product form matches this page's DE-CIX domain (a switch port plus a cross-connect, with switching equipment residing in neutral colocation facilities), and the mechanics are not repeated.

L2 Data Link

The principles of a shared layer-2 fabric and the misconfiguration-propagation risk it brings are explained fully at L2 of this page's DE-CIX domain and are not repeated here. What deserves separate treatment for this domain at this layer is a scale effect: as one of the world's largest shared layer-2 fabrics, both its participant count and the size of indiv…

L3 Network

The mechanics of route servers and multilateral peering, the role of RPKI route origin validation together with participants' own issuance obligation, and the principle by which blackholing discards DDoS traffic at the IXP are all explained fully at L3 of this page's DE-CIX domain and are not repeated here.

L4 Transport

This layer is explicitly empty — no product or service. The reason matches this page's DE-CIX domain: an IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange, it does not terminate, proxy or optimise participants' transport-layer connections, and traffic crossing the fabric is transparent payload to it.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (see L3), and the member self-service portal is an application-layer matter (see L7).

L6 Presentation

This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; the fabric itself does not encrypt traffic crossing it, and confidentiality is each participant's own responsibility (mechanism explained at L6 of this page's DE-CIX domain).

L7 Application

The conventional parts (member portal, traffic statistics, cloud connect, closed user groups) resemble this page's DE-CIX domain in form and the mechanics are not repeated. What genuinely deserves separate treatment at this layer is how its governance structure manifests: this domain is a neutral, independent, not-for-profit organisation owned collectively b…

LINX

Home turf: L1 / L2

L1 Physical

This is this domain's star layer, because its footprint thinking at this layer differs from both other IXP domains on this page. The physical-layer product form is generic (a switch port plus a cross-connect, with equipment residing in neutral facilities); see the DE-CIX domain for mechanics, not repeated here.

L2 Data Link

The principles of a shared layer-2 fabric, along with the risk of misconfiguration spilling over within a shared broadcast domain and the port discipline it demands, are explained fully at L2 of this page's DE-CIX domain, with the scale dimension added at L2 of the AMS-IX domain, and are not repeated here.

L3 Network

Route servers and multilateral peering, RPKI route origin validation together with participants' own issuance obligation, and blackholing mechanics are all explained fully at L3 of this page's DE-CIX domain, with the scale-related route-hygiene responsibility at L3 of the AMS-IX domain, and are not repeated here.

L4 Transport

This layer is explicitly empty — no product or service. The reason matches this page's other IXP domains: an IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange, and it does not terminate, proxy or optimise participants' transport-layer connections.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions are layer-3 routing-protocol sessions (see L3), and the member portal is an application-layer matter (see L7).

L6 Presentation

This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; the fabric itself does not encrypt traffic crossing it, and confidentiality is each participant's own responsibility (see L6 of this page's DE-CIX domain for mechanics).

L7 Application

The conventional parts (member portal, traffic statistics, private interconnection and cloud connect style value-added services) resemble this page's DE-CIX domain in form and the mechanics are not repeated.

HKIX

Home turf: L2 / L3

L1 Physical

The physical-layer product form is generic (a switch port plus a cross-connect); see this page's DE-CIX domain for mechanics, not repeated here. This domain has one peculiarity of origin at this layer: it is operated by the Chinese University of Hong Kong, and its earliest exchange facilities were located on campus, later expanding into Hong Kong's commercia…

L2 Data Link

The principles of a shared layer-2 fabric and the inherent risk of a shared broadcast domain are explained fully at L2 of this page's DE-CIX domain; why port discipline must be stricter under scale effects is at L2 of the AMS-IX domain; and the trade-off of independent fabrics between home market and regional sites is at L2 of the LINX domain.

L3 Network

This is this domain's other star layer, because among the four IXP domains on this site it best illustrates why IXPs exist at all. Route server, multilateral peering, RPKI and blackholing mechanics are at L3 of this page's DE-CIX domain and are not repeated.

L4 Transport

This layer is explicitly empty — no product or service. The reason matches this page's other IXP domains: an IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange, it does not terminate, proxy or optimise participants' transport-layer connections, and traffic crossing the fabric is transparent payload to it.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (see L3), and the member self-service interface is an application-layer matter (see L7).

L6 Presentation

This layer is explicitly empty — no product or service. This domain has no standalone encryption or presentation-layer product; the fabric itself does not encrypt traffic crossing it, and confidentiality is each participant's own responsibility (see L6 of this page's DE-CIX domain for mechanics).

L7 Application

The conventional parts (member portal, traffic statistics, billing and tickets) resemble this page's DE-CIX domain in form and the mechanics are not repeated. What deserves singling out for this domain at this layer is the mark its non-commercial origin left on service positioning: operated by a university and starting as a public-benefit local interconnecti…

Equinix IX

Home turf: L1 / L7

L1 Physical

This is one of this domain's star layers, because its role at this layer is completely inverted relative to the four preceding IXP domains on this site. All four of those own no facilities and lodge their switching equipment inside neutral colocation providers' buildings (L1 of this page's DE-CIX domain calls that a symbiosis); this domain is that colocation…

L2 Data Link

The principles of a shared layer-2 fabric and the inherent risk of a shared broadcast domain are explained fully at L2 of this page's DE-CIX domain, and why port discipline must be stricter under scale effects is at L2 of the AMS-IX domain. Those mechanics are not repeated here.

L3 Network

The mechanics of route servers and multilateral peering, RPKI route origin validation together with participants' own issuance obligation, and blackholing are all explained fully at L3 of this page's DE-CIX domain, with the scale-related route-hygiene responsibility at L3 of the AMS-IX domain, and are not repeated here.

L4 Transport

This layer is explicitly empty — no product or service. The reason matches this page's other IXP domains: an IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange, it does not terminate, proxy or optimise participants' transport-layer connections, and traffic crossing the fabric is transparent payload to it.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (see L3), and the customer self-service portal is an application-layer matter (see L7).

L6 Presentation

L7 Application

This is this domain's second star layer, because it holds a structural tension found nowhere else on this site. A facility operator's principal interconnection revenue comes substantially from cross-connects — a dedicated physical cable between two customers, billed per cable per month — and a public exchange fabric is to some degree a substitute for cross-c…

SIX (Seattle)

Home turf: L3 / L7

L1 Physical

The physical-layer product form is generic (a switch port plus a cross-connect); see L1 of this page's DE-CIX domain for mechanics, not repeated here. What characterises this domain at this layer is restraint of scope: it concentrates mainly on carrier hotels in Seattle (buildings such as the Westin Building) and a small number of other facilities in that ar…

L2 Data Link

The principles of a shared layer-2 fabric and the inherent risk of a shared broadcast domain are explained fully at L2 of this page's DE-CIX domain, with port discipline under scale effects at L2 of the AMS-IX domain, and are not repeated here.

L3 Network

This is one of this domain's star layers, because the value of the low-barrier strategy is ultimately realised here. Route server, multilateral peering and RPKI mechanics are at L3 of this page's DE-CIX domain and are not repeated.

L4 Transport

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (see L3), and the member self-service interface is an application-layer matter (see L7).

L6 Presentation

L7 Application

This is this domain's second star layer and where its entire differentiation lies: very low access cost plus lean non-profit operation. It has long provided access at fees far below commercial IXPs (a model based historically on predominantly one-time fees earned it its reputation, and the current fee structure should be checked against latest official discl…

JPIX

Home turf: L1 / L3

L1 Physical

This is one of this domain's star layers. The physical-layer product form is generic (a switch port plus a cross-connect, with equipment lodging in neutral facilities); see L1 of this site's DE-CIX domain for mechanics, not repeated here.

L2 Data Link

The principles of a shared layer-2 fabric and the inherent risk of a shared broadcast domain are explained fully at L2 of this site's DE-CIX domain, port discipline under scale effects at L2 of the AMS-IX domain, and the structure and trade-offs of independent per-city fabrics analysed fully at L2 of this site's LINX domain (cross-city peering requires separ…

L3 Network

This is this domain's second star layer, because the structure of the market it operates in produces a problem at this layer that no other IXP domain on this site has. Route server, multilateral peering and RPKI mechanics are at L3 of this site's DE-CIX domain and are not repeated. The core problem is fragmented reachability.

L4 Transport

This layer is explicitly empty — no product or service. The reason matches this site's other IXP domains: an IXP's responsibility ends at layer-2 forwarding and layer-3 route exchange, it does not terminate, proxy or optimise participants' transport-layer connections, and traffic crossing the fabric is transparent payload to it.

L5 Session

This layer is explicitly empty — no product or service. This domain offers no session-layer product: BGP sessions between participants are layer-3 routing-protocol sessions (see L3), and the member self-service portal is an application-layer matter (see L7).

L6 Presentation

L7 Application

The conventional parts (member portal, traffic statistics, billing and tickets) resemble this site's DE-CIX domain in form and the mechanics are not repeated. What this domain should add at this layer echoes the fragmented landscape at L3: in a market where joining several IXPs may be necessary, traffic statistics serve not only to review an individual port'…